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redict/src/module.c
Yossi Gottlieb 67b43f75e2 Modules: expose real client on conn events. 
When REDISMODULE_EVENT_CLIENT_CHANGE events are delivered, modules may
want to mutate the client state (e.g. perform authentication).

This change links the module context with the real client rather than a
fake client for these events.
2020-09-30 17:06:57 +03:00

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/*
* Copyright (c) 2016, Salvatore Sanfilippo <antirez at gmail dot com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Redis nor the names of its contributors may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "server.h"
#include "cluster.h"
#include "rdb.h"
#include <dlfcn.h>
#include <sys/stat.h>
#include <sys/wait.h>
/* --------------------------------------------------------------------------
* Private data structures used by the modules system. Those are data
* structures that are never exposed to Redis Modules, if not as void
* pointers that have an API the module can call with them)
* -------------------------------------------------------------------------- */
typedef struct RedisModuleInfoCtx {
struct RedisModule *module;
const char *requested_section;
sds info; /* info string we collected so far */
int sections; /* number of sections we collected so far */
int in_section; /* indication if we're in an active section or not */
int in_dict_field; /* indication that we're currently appending to a dict */
} RedisModuleInfoCtx;
typedef void (*RedisModuleInfoFunc)(RedisModuleInfoCtx *ctx, int for_crash_report);
/* This structure represents a module inside the system. */
struct RedisModule {
void *handle; /* Module dlopen() handle. */
char *name; /* Module name. */
int ver; /* Module version. We use just progressive integers. */
int apiver; /* Module API version as requested during initialization.*/
list *types; /* Module data types. */
list *usedby; /* List of modules using APIs from this one. */
list *using; /* List of modules we use some APIs of. */
list *filters; /* List of filters the module has registered. */
int in_call; /* RM_Call() nesting level */
int in_hook; /* Hooks callback nesting level for this module (0 or 1). */
int options; /* Module options and capabilities. */
int blocked_clients; /* Count of RedisModuleBlockedClient in this module. */
RedisModuleInfoFunc info_cb; /* Callback for module to add INFO fields. */
};
typedef struct RedisModule RedisModule;
/* This represents a shared API. Shared APIs will be used to populate
* the server.sharedapi dictionary, mapping names of APIs exported by
* modules for other modules to use, to their structure specifying the
* function pointer that can be called. */
struct RedisModuleSharedAPI {
void *func;
RedisModule *module;
};
typedef struct RedisModuleSharedAPI RedisModuleSharedAPI;
static dict *modules; /* Hash table of modules. SDS -> RedisModule ptr.*/
/* Entries in the context->amqueue array, representing objects to free
* when the callback returns. */
struct AutoMemEntry {
void *ptr;
int type;
};
/* AutMemEntry type field values. */
#define REDISMODULE_AM_KEY 0
#define REDISMODULE_AM_STRING 1
#define REDISMODULE_AM_REPLY 2
#define REDISMODULE_AM_FREED 3 /* Explicitly freed by user already. */
#define REDISMODULE_AM_DICT 4
#define REDISMODULE_AM_INFO 5
/* The pool allocator block. Redis Modules can allocate memory via this special
* allocator that will automatically release it all once the callback returns.
* This means that it can only be used for ephemeral allocations. However
* there are two advantages for modules to use this API:
*
* 1) The memory is automatically released when the callback returns.
* 2) This allocator is faster for many small allocations since whole blocks
* are allocated, and small pieces returned to the caller just advancing
* the index of the allocation.
*
* Allocations are always rounded to the size of the void pointer in order
* to always return aligned memory chunks. */
#define REDISMODULE_POOL_ALLOC_MIN_SIZE (1024*8)
#define REDISMODULE_POOL_ALLOC_ALIGN (sizeof(void*))
typedef struct RedisModulePoolAllocBlock {
uint32_t size;
uint32_t used;
struct RedisModulePoolAllocBlock *next;
char memory[];
} RedisModulePoolAllocBlock;
/* This structure represents the context in which Redis modules operate.
* Most APIs module can access, get a pointer to the context, so that the API
* implementation can hold state across calls, or remember what to free after
* the call and so forth.
*
* Note that not all the context structure is always filled with actual values
* but only the fields needed in a given context. */
struct RedisModuleBlockedClient;
struct RedisModuleCtx {
void *getapifuncptr; /* NOTE: Must be the first field. */
struct RedisModule *module; /* Module reference. */
client *client; /* Client calling a command. */
struct RedisModuleBlockedClient *blocked_client; /* Blocked client for
thread safe context. */
struct AutoMemEntry *amqueue; /* Auto memory queue of objects to free. */
int amqueue_len; /* Number of slots in amqueue. */
int amqueue_used; /* Number of used slots in amqueue. */
int flags; /* REDISMODULE_CTX_... flags. */
void **postponed_arrays; /* To set with RM_ReplySetArrayLength(). */
int postponed_arrays_count; /* Number of entries in postponed_arrays. */
void *blocked_privdata; /* Privdata set when unblocking a client. */
RedisModuleString *blocked_ready_key; /* Key ready when the reply callback
gets called for clients blocked
on keys. */
/* Used if there is the REDISMODULE_CTX_KEYS_POS_REQUEST flag set. */
int *keys_pos;
int keys_count;
struct RedisModulePoolAllocBlock *pa_head;
redisOpArray saved_oparray; /* When propagating commands in a callback
we reallocate the "also propagate" op
array. Here we save the old one to
restore it later. */
};
typedef struct RedisModuleCtx RedisModuleCtx;
#define REDISMODULE_CTX_INIT {(void*)(unsigned long)&RM_GetApi, NULL, NULL, NULL, NULL, 0, 0, 0, NULL, 0, NULL, NULL, NULL, 0, NULL, {0}}
#define REDISMODULE_CTX_MULTI_EMITTED (1<<0)
#define REDISMODULE_CTX_AUTO_MEMORY (1<<1)
#define REDISMODULE_CTX_KEYS_POS_REQUEST (1<<2)
#define REDISMODULE_CTX_BLOCKED_REPLY (1<<3)
#define REDISMODULE_CTX_BLOCKED_TIMEOUT (1<<4)
#define REDISMODULE_CTX_THREAD_SAFE (1<<5)
#define REDISMODULE_CTX_BLOCKED_DISCONNECTED (1<<6)
#define REDISMODULE_CTX_MODULE_COMMAND_CALL (1<<7)
/* This represents a Redis key opened with RM_OpenKey(). */
struct RedisModuleKey {
RedisModuleCtx *ctx;
redisDb *db;
robj *key; /* Key name object. */
robj *value; /* Value object, or NULL if the key was not found. */
void *iter; /* Iterator. */
int mode; /* Opening mode. */
/* Zset iterator. */
uint32_t ztype; /* REDISMODULE_ZSET_RANGE_* */
zrangespec zrs; /* Score range. */
zlexrangespec zlrs; /* Lex range. */
uint32_t zstart; /* Start pos for positional ranges. */
uint32_t zend; /* End pos for positional ranges. */
void *zcurrent; /* Zset iterator current node. */
int zer; /* Zset iterator end reached flag
(true if end was reached). */
};
typedef struct RedisModuleKey RedisModuleKey;
/* RedisModuleKey 'ztype' values. */
#define REDISMODULE_ZSET_RANGE_NONE 0 /* This must always be 0. */
#define REDISMODULE_ZSET_RANGE_LEX 1
#define REDISMODULE_ZSET_RANGE_SCORE 2
#define REDISMODULE_ZSET_RANGE_POS 3
/* Function pointer type of a function representing a command inside
* a Redis module. */
struct RedisModuleBlockedClient;
typedef int (*RedisModuleCmdFunc) (RedisModuleCtx *ctx, void **argv, int argc);
typedef void (*RedisModuleDisconnectFunc) (RedisModuleCtx *ctx, struct RedisModuleBlockedClient *bc);
/* This struct holds the information about a command registered by a module.*/
struct RedisModuleCommandProxy {
struct RedisModule *module;
RedisModuleCmdFunc func;
struct redisCommand *rediscmd;
};
typedef struct RedisModuleCommandProxy RedisModuleCommandProxy;
#define REDISMODULE_REPLYFLAG_NONE 0
#define REDISMODULE_REPLYFLAG_TOPARSE (1<<0) /* Protocol must be parsed. */
#define REDISMODULE_REPLYFLAG_NESTED (1<<1) /* Nested reply object. No proto
or struct free. */
/* Reply of RM_Call() function. The function is filled in a lazy
* way depending on the function called on the reply structure. By default
* only the type, proto and protolen are filled. */
typedef struct RedisModuleCallReply {
RedisModuleCtx *ctx;
int type; /* REDISMODULE_REPLY_... */
int flags; /* REDISMODULE_REPLYFLAG_... */
size_t len; /* Len of strings or num of elements of arrays. */
char *proto; /* Raw reply protocol. An SDS string at top-level object. */
size_t protolen;/* Length of protocol. */
union {
const char *str; /* String pointer for string and error replies. This
does not need to be freed, always points inside
a reply->proto buffer of the reply object or, in
case of array elements, of parent reply objects. */
long long ll; /* Reply value for integer reply. */
struct RedisModuleCallReply *array; /* Array of sub-reply elements. */
} val;
} RedisModuleCallReply;
/* Structure representing a blocked client. We get a pointer to such
* an object when blocking from modules. */
typedef struct RedisModuleBlockedClient {
client *client; /* Pointer to the blocked client. or NULL if the client
was destroyed during the life of this object. */
RedisModule *module; /* Module blocking the client. */
RedisModuleCmdFunc reply_callback; /* Reply callback on normal completion.*/
RedisModuleCmdFunc timeout_callback; /* Reply callback on timeout. */
RedisModuleDisconnectFunc disconnect_callback; /* Called on disconnection.*/
void (*free_privdata)(RedisModuleCtx*,void*);/* privdata cleanup callback.*/
void *privdata; /* Module private data that may be used by the reply
or timeout callback. It is set via the
RedisModule_UnblockClient() API. */
client *reply_client; /* Fake client used to accumulate replies
in thread safe contexts. */
int dbid; /* Database number selected by the original client. */
int blocked_on_keys; /* If blocked via RM_BlockClientOnKeys(). */
int unblocked; /* Already on the moduleUnblocked list. */
} RedisModuleBlockedClient;
static pthread_mutex_t moduleUnblockedClientsMutex = PTHREAD_MUTEX_INITIALIZER;
static list *moduleUnblockedClients;
/* We need a mutex that is unlocked / relocked in beforeSleep() in order to
* allow thread safe contexts to execute commands at a safe moment. */
static pthread_mutex_t moduleGIL = PTHREAD_MUTEX_INITIALIZER;
/* Function pointer type for keyspace event notification subscriptions from modules. */
typedef int (*RedisModuleNotificationFunc) (RedisModuleCtx *ctx, int type, const char *event, RedisModuleString *key);
/* Keyspace notification subscriber information.
* See RM_SubscribeToKeyspaceEvents() for more information. */
typedef struct RedisModuleKeyspaceSubscriber {
/* The module subscribed to the event */
RedisModule *module;
/* Notification callback in the module*/
RedisModuleNotificationFunc notify_callback;
/* A bit mask of the events the module is interested in */
int event_mask;
/* Active flag set on entry, to avoid reentrant subscribers
* calling themselves */
int active;
} RedisModuleKeyspaceSubscriber;
/* The module keyspace notification subscribers list */
static list *moduleKeyspaceSubscribers;
/* Static client recycled for when we need to provide a context with a client
* in a situation where there is no client to provide. This avoids allocating
* a new client per round. For instance this is used in the keyspace
* notifications, timers and cluster messages callbacks. */
static client *moduleFreeContextReusedClient;
/* Data structures related to the exported dictionary data structure. */
typedef struct RedisModuleDict {
rax *rax; /* The radix tree. */
} RedisModuleDict;
typedef struct RedisModuleDictIter {
RedisModuleDict *dict;
raxIterator ri;
} RedisModuleDictIter;
typedef struct RedisModuleCommandFilterCtx {
RedisModuleString **argv;
int argc;
} RedisModuleCommandFilterCtx;
typedef void (*RedisModuleCommandFilterFunc) (RedisModuleCommandFilterCtx *filter);
typedef struct RedisModuleCommandFilter {
/* The module that registered the filter */
RedisModule *module;
/* Filter callback function */
RedisModuleCommandFilterFunc callback;
/* REDISMODULE_CMDFILTER_* flags */
int flags;
} RedisModuleCommandFilter;
/* Registered filters */
static list *moduleCommandFilters;
typedef void (*RedisModuleForkDoneHandler) (int exitcode, int bysignal, void *user_data);
static struct RedisModuleForkInfo {
RedisModuleForkDoneHandler done_handler;
void* done_handler_user_data;
} moduleForkInfo = {0};
typedef struct RedisModuleServerInfoData {
rax *rax; /* parsed info data. */
} RedisModuleServerInfoData;
/* Flags for moduleCreateArgvFromUserFormat(). */
#define REDISMODULE_ARGV_REPLICATE (1<<0)
#define REDISMODULE_ARGV_NO_AOF (1<<1)
#define REDISMODULE_ARGV_NO_REPLICAS (1<<2)
/* Determine whether Redis should signalModifiedKey implicitly.
* In case 'ctx' has no 'module' member (and therefore no module->options),
* we assume default behavior, that is, Redis signals.
* (see RM_GetThreadSafeContext) */
#define SHOULD_SIGNAL_MODIFIED_KEYS(ctx) \
ctx->module? !(ctx->module->options & REDISMODULE_OPTION_NO_IMPLICIT_SIGNAL_MODIFIED) : 1
/* Server events hooks data structures and defines: this modules API
* allow modules to subscribe to certain events in Redis, such as
* the start and end of an RDB or AOF save, the change of role in replication,
* and similar other events. */
typedef struct RedisModuleEventListener {
RedisModule *module;
RedisModuleEvent event;
RedisModuleEventCallback callback;
} RedisModuleEventListener;
list *RedisModule_EventListeners; /* Global list of all the active events. */
unsigned long long ModulesInHooks = 0; /* Total number of modules in hooks
callbacks right now. */
/* Data structures related to the redis module users */
/* This is the object returned by RM_CreateModuleUser(). The module API is
* able to create users, set ACLs to such users, and later authenticate
* clients using such newly created users. */
typedef struct RedisModuleUser {
user *user; /* Reference to the real redis user */
} RedisModuleUser;
/* --------------------------------------------------------------------------
* Prototypes
* -------------------------------------------------------------------------- */
void RM_FreeCallReply(RedisModuleCallReply *reply);
void RM_CloseKey(RedisModuleKey *key);
void autoMemoryCollect(RedisModuleCtx *ctx);
robj **moduleCreateArgvFromUserFormat(const char *cmdname, const char *fmt, int *argcp, int *flags, va_list ap);
void moduleReplicateMultiIfNeeded(RedisModuleCtx *ctx);
void RM_ZsetRangeStop(RedisModuleKey *kp);
static void zsetKeyReset(RedisModuleKey *key);
void RM_FreeDict(RedisModuleCtx *ctx, RedisModuleDict *d);
void RM_FreeServerInfo(RedisModuleCtx *ctx, RedisModuleServerInfoData *data);
/* --------------------------------------------------------------------------
* Heap allocation raw functions
* -------------------------------------------------------------------------- */
/* Use like malloc(). Memory allocated with this function is reported in
* Redis INFO memory, used for keys eviction according to maxmemory settings
* and in general is taken into account as memory allocated by Redis.
* You should avoid using malloc(). */
void *RM_Alloc(size_t bytes) {
return zmalloc(bytes);
}
/* Use like calloc(). Memory allocated with this function is reported in
* Redis INFO memory, used for keys eviction according to maxmemory settings
* and in general is taken into account as memory allocated by Redis.
* You should avoid using calloc() directly. */
void *RM_Calloc(size_t nmemb, size_t size) {
return zcalloc(nmemb*size);
}
/* Use like realloc() for memory obtained with RedisModule_Alloc(). */
void* RM_Realloc(void *ptr, size_t bytes) {
return zrealloc(ptr,bytes);
}
/* Use like free() for memory obtained by RedisModule_Alloc() and
* RedisModule_Realloc(). However you should never try to free with
* RedisModule_Free() memory allocated with malloc() inside your module. */
void RM_Free(void *ptr) {
zfree(ptr);
}
/* Like strdup() but returns memory allocated with RedisModule_Alloc(). */
char *RM_Strdup(const char *str) {
return zstrdup(str);
}
/* --------------------------------------------------------------------------
* Pool allocator
* -------------------------------------------------------------------------- */
/* Release the chain of blocks used for pool allocations. */
void poolAllocRelease(RedisModuleCtx *ctx) {
RedisModulePoolAllocBlock *head = ctx->pa_head, *next;
while(head != NULL) {
next = head->next;
zfree(head);
head = next;
}
ctx->pa_head = NULL;
}
/* Return heap allocated memory that will be freed automatically when the
* module callback function returns. Mostly suitable for small allocations
* that are short living and must be released when the callback returns
* anyway. The returned memory is aligned to the architecture word size
* if at least word size bytes are requested, otherwise it is just
* aligned to the next power of two, so for example a 3 bytes request is
* 4 bytes aligned while a 2 bytes request is 2 bytes aligned.
*
* There is no realloc style function since when this is needed to use the
* pool allocator is not a good idea.
*
* The function returns NULL if `bytes` is 0. */
void *RM_PoolAlloc(RedisModuleCtx *ctx, size_t bytes) {
if (bytes == 0) return NULL;
RedisModulePoolAllocBlock *b = ctx->pa_head;
size_t left = b ? b->size - b->used : 0;
/* Fix alignment. */
if (left >= bytes) {
size_t alignment = REDISMODULE_POOL_ALLOC_ALIGN;
while (bytes < alignment && alignment/2 >= bytes) alignment /= 2;
if (b->used % alignment)
b->used += alignment - (b->used % alignment);
left = (b->used > b->size) ? 0 : b->size - b->used;
}
/* Create a new block if needed. */
if (left < bytes) {
size_t blocksize = REDISMODULE_POOL_ALLOC_MIN_SIZE;
if (blocksize < bytes) blocksize = bytes;
b = zmalloc(sizeof(*b) + blocksize);
b->size = blocksize;
b->used = 0;
b->next = ctx->pa_head;
ctx->pa_head = b;
}
char *retval = b->memory + b->used;
b->used += bytes;
return retval;
}
/* --------------------------------------------------------------------------
* Helpers for modules API implementation
* -------------------------------------------------------------------------- */
/* Create an empty key of the specified type. 'kp' must point to a key object
* opened for writing where the .value member is set to NULL because the
* key was found to be non existing.
*
* On success REDISMODULE_OK is returned and the key is populated with
* the value of the specified type. The function fails and returns
* REDISMODULE_ERR if:
*
* 1) The key is not open for writing.
* 2) The key is not empty.
* 3) The specified type is unknown.
*/
int moduleCreateEmptyKey(RedisModuleKey *key, int type) {
robj *obj;
/* The key must be open for writing and non existing to proceed. */
if (!(key->mode & REDISMODULE_WRITE) || key->value)
return REDISMODULE_ERR;
switch(type) {
case REDISMODULE_KEYTYPE_LIST:
obj = createQuicklistObject();
quicklistSetOptions(obj->ptr, server.list_max_ziplist_size,
server.list_compress_depth);
break;
case REDISMODULE_KEYTYPE_ZSET:
obj = createZsetZiplistObject();
break;
case REDISMODULE_KEYTYPE_HASH:
obj = createHashObject();
break;
default: return REDISMODULE_ERR;
}
dbAdd(key->db,key->key,obj);
key->value = obj;
return REDISMODULE_OK;
}
/* This function is called in low-level API implementation functions in order
* to check if the value associated with the key remained empty after an
* operation that removed elements from an aggregate data type.
*
* If this happens, the key is deleted from the DB and the key object state
* is set to the right one in order to be targeted again by write operations
* possibly recreating the key if needed.
*
* The function returns 1 if the key value object is found empty and is
* deleted, otherwise 0 is returned. */
int moduleDelKeyIfEmpty(RedisModuleKey *key) {
if (!(key->mode & REDISMODULE_WRITE) || key->value == NULL) return 0;
int isempty;
robj *o = key->value;
switch(o->type) {
case OBJ_LIST: isempty = listTypeLength(o) == 0; break;
case OBJ_SET: isempty = setTypeSize(o) == 0; break;
case OBJ_ZSET: isempty = zsetLength(o) == 0; break;
case OBJ_HASH: isempty = hashTypeLength(o) == 0; break;
case OBJ_STREAM: isempty = streamLength(o) == 0; break;
default: isempty = 0;
}
if (isempty) {
dbDelete(key->db,key->key);
key->value = NULL;
return 1;
} else {
return 0;
}
}
/* --------------------------------------------------------------------------
* Service API exported to modules
*
* Note that all the exported APIs are called RM_<funcname> in the core
* and RedisModule_<funcname> in the module side (defined as function
* pointers in redismodule.h). In this way the dynamic linker does not
* mess with our global function pointers, overriding it with the symbols
* defined in the main executable having the same names.
* -------------------------------------------------------------------------- */
/* Lookup the requested module API and store the function pointer into the
* target pointer. The function returns REDISMODULE_ERR if there is no such
* named API, otherwise REDISMODULE_OK.
*
* This function is not meant to be used by modules developer, it is only
* used implicitly by including redismodule.h. */
int RM_GetApi(const char *funcname, void **targetPtrPtr) {
dictEntry *he = dictFind(server.moduleapi, funcname);
if (!he) return REDISMODULE_ERR;
*targetPtrPtr = dictGetVal(he);
return REDISMODULE_OK;
}
/* Helper function for when a command callback is called, in order to handle
* details needed to correctly replicate commands. */
void moduleHandlePropagationAfterCommandCallback(RedisModuleCtx *ctx) {
client *c = ctx->client;
/* We don't need to do anything here if the context was never used
* in order to propagate commands. */
if (!(ctx->flags & REDISMODULE_CTX_MULTI_EMITTED)) return;
if (c->flags & CLIENT_LUA) return;
/* Handle the replication of the final EXEC, since whatever a command
* emits is always wrapped around MULTI/EXEC. */
alsoPropagate(server.execCommand,c->db->id,&shared.exec,1,
PROPAGATE_AOF|PROPAGATE_REPL);
/* If this is not a module command context (but is instead a simple
* callback context), we have to handle directly the "also propagate"
* array and emit it. In a module command call this will be handled
* directly by call(). */
if (!(ctx->flags & REDISMODULE_CTX_MODULE_COMMAND_CALL) &&
server.also_propagate.numops)
{
for (int j = 0; j < server.also_propagate.numops; j++) {
redisOp *rop = &server.also_propagate.ops[j];
int target = rop->target;
if (target)
propagate(rop->cmd,rop->dbid,rop->argv,rop->argc,target);
}
redisOpArrayFree(&server.also_propagate);
/* Restore the previous oparray in case of nexted use of the API. */
server.also_propagate = ctx->saved_oparray;
/* We're done with saved_oparray, let's invalidate it. */
redisOpArrayInit(&ctx->saved_oparray);
}
}
/* Free the context after the user function was called. */
void moduleFreeContext(RedisModuleCtx *ctx) {
moduleHandlePropagationAfterCommandCallback(ctx);
autoMemoryCollect(ctx);
poolAllocRelease(ctx);
if (ctx->postponed_arrays) {
zfree(ctx->postponed_arrays);
ctx->postponed_arrays_count = 0;
serverLog(LL_WARNING,
"API misuse detected in module %s: "
"RedisModule_ReplyWithArray(REDISMODULE_POSTPONED_ARRAY_LEN) "
"not matched by the same number of RedisModule_SetReplyArrayLen() "
"calls.",
ctx->module->name);
}
if (ctx->flags & REDISMODULE_CTX_THREAD_SAFE) freeClient(ctx->client);
}
/* This Redis command binds the normal Redis command invocation with commands
* exported by modules. */
void RedisModuleCommandDispatcher(client *c) {
RedisModuleCommandProxy *cp = (void*)(unsigned long)c->cmd->getkeys_proc;
RedisModuleCtx ctx = REDISMODULE_CTX_INIT;
ctx.flags |= REDISMODULE_CTX_MODULE_COMMAND_CALL;
ctx.module = cp->module;
ctx.client = c;
cp->func(&ctx,(void**)c->argv,c->argc);
moduleFreeContext(&ctx);
/* In some cases processMultibulkBuffer uses sdsMakeRoomFor to
* expand the query buffer, and in order to avoid a big object copy
* the query buffer SDS may be used directly as the SDS string backing
* the client argument vectors: sometimes this will result in the SDS
* string having unused space at the end. Later if a module takes ownership
* of the RedisString, such space will be wasted forever. Inside the
* Redis core this is not a problem because tryObjectEncoding() is called
* before storing strings in the key space. Here we need to do it
* for the module. */
for (int i = 0; i < c->argc; i++) {
/* Only do the work if the module took ownership of the object:
* in that case the refcount is no longer 1. */
if (c->argv[i]->refcount > 1)
trimStringObjectIfNeeded(c->argv[i]);
}
}
/* This function returns the list of keys, with the same interface as the
* 'getkeys' function of the native commands, for module commands that exported
* the "getkeys-api" flag during the registration. This is done when the
* list of keys are not at fixed positions, so that first/last/step cannot
* be used.
*
* In order to accomplish its work, the module command is called, flagging
* the context in a way that the command can recognize this is a special
* "get keys" call by calling RedisModule_IsKeysPositionRequest(ctx). */
int *moduleGetCommandKeysViaAPI(struct redisCommand *cmd, robj **argv, int argc, int *numkeys) {
RedisModuleCommandProxy *cp = (void*)(unsigned long)cmd->getkeys_proc;
RedisModuleCtx ctx = REDISMODULE_CTX_INIT;
ctx.module = cp->module;
ctx.client = NULL;
ctx.flags |= REDISMODULE_CTX_KEYS_POS_REQUEST;
cp->func(&ctx,(void**)argv,argc);
int *res = ctx.keys_pos;
if (numkeys) *numkeys = ctx.keys_count;
moduleFreeContext(&ctx);
return res;
}
/* Return non-zero if a module command, that was declared with the
* flag "getkeys-api", is called in a special way to get the keys positions
* and not to get executed. Otherwise zero is returned. */
int RM_IsKeysPositionRequest(RedisModuleCtx *ctx) {
return (ctx->flags & REDISMODULE_CTX_KEYS_POS_REQUEST) != 0;
}
/* When a module command is called in order to obtain the position of
* keys, since it was flagged as "getkeys-api" during the registration,
* the command implementation checks for this special call using the
* RedisModule_IsKeysPositionRequest() API and uses this function in
* order to report keys, like in the following example:
*
* if (RedisModule_IsKeysPositionRequest(ctx)) {
* RedisModule_KeyAtPos(ctx,1);
* RedisModule_KeyAtPos(ctx,2);
* }
*
* Note: in the example below the get keys API would not be needed since
* keys are at fixed positions. This interface is only used for commands
* with a more complex structure. */
void RM_KeyAtPos(RedisModuleCtx *ctx, int pos) {
if (!(ctx->flags & REDISMODULE_CTX_KEYS_POS_REQUEST)) return;
if (pos <= 0) return;
ctx->keys_pos = zrealloc(ctx->keys_pos,sizeof(int)*(ctx->keys_count+1));
ctx->keys_pos[ctx->keys_count++] = pos;
}
/* Helper for RM_CreateCommand(). Turns a string representing command
* flags into the command flags used by the Redis core.
*
* It returns the set of flags, or -1 if unknown flags are found. */
int64_t commandFlagsFromString(char *s) {
int count, j;
int64_t flags = 0;
sds *tokens = sdssplitlen(s,strlen(s)," ",1,&count);
for (j = 0; j < count; j++) {
char *t = tokens[j];
if (!strcasecmp(t,"write")) flags |= CMD_WRITE;
else if (!strcasecmp(t,"readonly")) flags |= CMD_READONLY;
else if (!strcasecmp(t,"admin")) flags |= CMD_ADMIN;
else if (!strcasecmp(t,"deny-oom")) flags |= CMD_DENYOOM;
else if (!strcasecmp(t,"deny-script")) flags |= CMD_NOSCRIPT;
else if (!strcasecmp(t,"allow-loading")) flags |= CMD_LOADING;
else if (!strcasecmp(t,"pubsub")) flags |= CMD_PUBSUB;
else if (!strcasecmp(t,"random")) flags |= CMD_RANDOM;
else if (!strcasecmp(t,"allow-stale")) flags |= CMD_STALE;
else if (!strcasecmp(t,"no-monitor")) flags |= CMD_SKIP_MONITOR;
else if (!strcasecmp(t,"no-slowlog")) flags |= CMD_SKIP_SLOWLOG;
else if (!strcasecmp(t,"fast")) flags |= CMD_FAST;
else if (!strcasecmp(t,"no-auth")) flags |= CMD_NO_AUTH;
else if (!strcasecmp(t,"getkeys-api")) flags |= CMD_MODULE_GETKEYS;
else if (!strcasecmp(t,"no-cluster")) flags |= CMD_MODULE_NO_CLUSTER;
else break;
}
sdsfreesplitres(tokens,count);
if (j != count) return -1; /* Some token not processed correctly. */
return flags;
}
/* Register a new command in the Redis server, that will be handled by
* calling the function pointer 'func' using the RedisModule calling
* convention. The function returns REDISMODULE_ERR if the specified command
* name is already busy or a set of invalid flags were passed, otherwise
* REDISMODULE_OK is returned and the new command is registered.
*
* This function must be called during the initialization of the module
* inside the RedisModule_OnLoad() function. Calling this function outside
* of the initialization function is not defined.
*
* The command function type is the following:
*
* int MyCommand_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc);
*
* And is supposed to always return REDISMODULE_OK.
*
* The set of flags 'strflags' specify the behavior of the command, and should
* be passed as a C string composed of space separated words, like for
* example "write deny-oom". The set of flags are:
*
* * **"write"**: The command may modify the data set (it may also read
* from it).
* * **"readonly"**: The command returns data from keys but never writes.
* * **"admin"**: The command is an administrative command (may change
* replication or perform similar tasks).
* * **"deny-oom"**: The command may use additional memory and should be
* denied during out of memory conditions.
* * **"deny-script"**: Don't allow this command in Lua scripts.
* * **"allow-loading"**: Allow this command while the server is loading data.
* Only commands not interacting with the data set
* should be allowed to run in this mode. If not sure
* don't use this flag.
* * **"pubsub"**: The command publishes things on Pub/Sub channels.
* * **"random"**: The command may have different outputs even starting
* from the same input arguments and key values.
* * **"allow-stale"**: The command is allowed to run on slaves that don't
* serve stale data. Don't use if you don't know what
* this means.
* * **"no-monitor"**: Don't propagate the command on monitor. Use this if
* the command has sensible data among the arguments.
* * **"no-slowlog"**: Don't log this command in the slowlog. Use this if
* the command has sensible data among the arguments.
* * **"fast"**: The command time complexity is not greater
* than O(log(N)) where N is the size of the collection or
* anything else representing the normal scalability
* issue with the command.
* * **"getkeys-api"**: The command implements the interface to return
* the arguments that are keys. Used when start/stop/step
* is not enough because of the command syntax.
* * **"no-cluster"**: The command should not register in Redis Cluster
* since is not designed to work with it because, for
* example, is unable to report the position of the
* keys, programmatically creates key names, or any
* other reason.
* * **"no-auth"**: This command can be run by an un-authenticated client.
* Normally this is used by a command that is used
* to authenticate a client.
*/
int RM_CreateCommand(RedisModuleCtx *ctx, const char *name, RedisModuleCmdFunc cmdfunc, const char *strflags, int firstkey, int lastkey, int keystep) {
int64_t flags = strflags ? commandFlagsFromString((char*)strflags) : 0;
if (flags == -1) return REDISMODULE_ERR;
if ((flags & CMD_MODULE_NO_CLUSTER) && server.cluster_enabled)
return REDISMODULE_ERR;
struct redisCommand *rediscmd;
RedisModuleCommandProxy *cp;
sds cmdname = sdsnew(name);
/* Check if the command name is busy. */
if (lookupCommand(cmdname) != NULL) {
sdsfree(cmdname);
return REDISMODULE_ERR;
}
/* Create a command "proxy", which is a structure that is referenced
* in the command table, so that the generic command that works as
* binding between modules and Redis, can know what function to call
* and what the module is.
*
* Note that we use the Redis command table 'getkeys_proc' in order to
* pass a reference to the command proxy structure. */
cp = zmalloc(sizeof(*cp));
cp->module = ctx->module;
cp->func = cmdfunc;
cp->rediscmd = zmalloc(sizeof(*rediscmd));
cp->rediscmd->name = cmdname;
cp->rediscmd->proc = RedisModuleCommandDispatcher;
cp->rediscmd->arity = -1;
cp->rediscmd->flags = flags | CMD_MODULE;
cp->rediscmd->getkeys_proc = (redisGetKeysProc*)(unsigned long)cp;
cp->rediscmd->firstkey = firstkey;
cp->rediscmd->lastkey = lastkey;
cp->rediscmd->keystep = keystep;
cp->rediscmd->microseconds = 0;
cp->rediscmd->calls = 0;
dictAdd(server.commands,sdsdup(cmdname),cp->rediscmd);
dictAdd(server.orig_commands,sdsdup(cmdname),cp->rediscmd);
cp->rediscmd->id = ACLGetCommandID(cmdname); /* ID used for ACL. */
return REDISMODULE_OK;
}
/* Called by RM_Init() to setup the `ctx->module` structure.
*
* This is an internal function, Redis modules developers don't need
* to use it. */
void RM_SetModuleAttribs(RedisModuleCtx *ctx, const char *name, int ver, int apiver) {
RedisModule *module;
if (ctx->module != NULL) return;
module = zmalloc(sizeof(*module));
module->name = sdsnew((char*)name);
module->ver = ver;
module->apiver = apiver;
module->types = listCreate();
module->usedby = listCreate();
module->using = listCreate();
module->filters = listCreate();
module->in_call = 0;
module->in_hook = 0;
module->options = 0;
module->info_cb = 0;
ctx->module = module;
}
/* Return non-zero if the module name is busy.
* Otherwise zero is returned. */
int RM_IsModuleNameBusy(const char *name) {
sds modulename = sdsnew(name);
dictEntry *de = dictFind(modules,modulename);
sdsfree(modulename);
return de != NULL;
}
/* Return the current UNIX time in milliseconds. */
long long RM_Milliseconds(void) {
return mstime();
}
/* Set flags defining capabilities or behavior bit flags.
*
* REDISMODULE_OPTIONS_HANDLE_IO_ERRORS:
* Generally, modules don't need to bother with this, as the process will just
* terminate if a read error happens, however, setting this flag would allow
* repl-diskless-load to work if enabled.
* The module should use RedisModule_IsIOError after reads, before using the
* data that was read, and in case of error, propagate it upwards, and also be
* able to release the partially populated value and all it's allocations. */
void RM_SetModuleOptions(RedisModuleCtx *ctx, int options) {
ctx->module->options = options;
}
/* Signals that the key is modified from user's perspective (i.e. invalidate WATCH
* and client side caching). */
int RM_SignalModifiedKey(RedisModuleCtx *ctx, RedisModuleString *keyname) {
signalModifiedKey(ctx->client,ctx->client->db,keyname);
return REDISMODULE_OK;
}
/* --------------------------------------------------------------------------
* Automatic memory management for modules
* -------------------------------------------------------------------------- */
/* Enable automatic memory management.
*
* The function must be called as the first function of a command implementation
* that wants to use automatic memory.
*
* When enabled, automatic memory management tracks and automatically frees
* keys, call replies and Redis string objects once the command returns. In most
* cases this eliminates the need of calling the following functions:
*
* 1) RedisModule_CloseKey()
* 2) RedisModule_FreeCallReply()
* 3) RedisModule_FreeString()
*
* These functions can still be used with automatic memory management enabled,
* to optimize loops that make numerous allocations for example. */
void RM_AutoMemory(RedisModuleCtx *ctx) {
ctx->flags |= REDISMODULE_CTX_AUTO_MEMORY;
}
/* Add a new object to release automatically when the callback returns. */
void autoMemoryAdd(RedisModuleCtx *ctx, int type, void *ptr) {
if (!(ctx->flags & REDISMODULE_CTX_AUTO_MEMORY)) return;
if (ctx->amqueue_used == ctx->amqueue_len) {
ctx->amqueue_len *= 2;
if (ctx->amqueue_len < 16) ctx->amqueue_len = 16;
ctx->amqueue = zrealloc(ctx->amqueue,sizeof(struct AutoMemEntry)*ctx->amqueue_len);
}
ctx->amqueue[ctx->amqueue_used].type = type;
ctx->amqueue[ctx->amqueue_used].ptr = ptr;
ctx->amqueue_used++;
}
/* Mark an object as freed in the auto release queue, so that users can still
* free things manually if they want.
*
* The function returns 1 if the object was actually found in the auto memory
* pool, otherwise 0 is returned. */
int autoMemoryFreed(RedisModuleCtx *ctx, int type, void *ptr) {
if (!(ctx->flags & REDISMODULE_CTX_AUTO_MEMORY)) return 0;
int count = (ctx->amqueue_used+1)/2;
for (int j = 0; j < count; j++) {
for (int side = 0; side < 2; side++) {
/* For side = 0 check right side of the array, for
* side = 1 check the left side instead (zig-zag scanning). */
int i = (side == 0) ? (ctx->amqueue_used - 1 - j) : j;
if (ctx->amqueue[i].type == type &&
ctx->amqueue[i].ptr == ptr)
{
ctx->amqueue[i].type = REDISMODULE_AM_FREED;
/* Switch the freed element and the last element, to avoid growing
* the queue unnecessarily if we allocate/free in a loop */
if (i != ctx->amqueue_used-1) {
ctx->amqueue[i] = ctx->amqueue[ctx->amqueue_used-1];
}
/* Reduce the size of the queue because we either moved the top
* element elsewhere or freed it */
ctx->amqueue_used--;
return 1;
}
}
}
return 0;
}
/* Release all the objects in queue. */
void autoMemoryCollect(RedisModuleCtx *ctx) {
if (!(ctx->flags & REDISMODULE_CTX_AUTO_MEMORY)) return;
/* Clear the AUTO_MEMORY flag from the context, otherwise the functions
* we call to free the resources, will try to scan the auto release
* queue to mark the entries as freed. */
ctx->flags &= ~REDISMODULE_CTX_AUTO_MEMORY;
int j;
for (j = 0; j < ctx->amqueue_used; j++) {
void *ptr = ctx->amqueue[j].ptr;
switch(ctx->amqueue[j].type) {
case REDISMODULE_AM_STRING: decrRefCount(ptr); break;
case REDISMODULE_AM_REPLY: RM_FreeCallReply(ptr); break;
case REDISMODULE_AM_KEY: RM_CloseKey(ptr); break;
case REDISMODULE_AM_DICT: RM_FreeDict(NULL,ptr); break;
case REDISMODULE_AM_INFO: RM_FreeServerInfo(NULL,ptr); break;
}
}
ctx->flags |= REDISMODULE_CTX_AUTO_MEMORY;
zfree(ctx->amqueue);
ctx->amqueue = NULL;
ctx->amqueue_len = 0;
ctx->amqueue_used = 0;
}
/* --------------------------------------------------------------------------
* String objects APIs
* -------------------------------------------------------------------------- */
/* Create a new module string object. The returned string must be freed
* with RedisModule_FreeString(), unless automatic memory is enabled.
*
* The string is created by copying the `len` bytes starting
* at `ptr`. No reference is retained to the passed buffer.
*
* The module context 'ctx' is optional and may be NULL if you want to create
* a string out of the context scope. However in that case, the automatic
* memory management will not be available, and the string memory must be
* managed manually. */
RedisModuleString *RM_CreateString(RedisModuleCtx *ctx, const char *ptr, size_t len) {
RedisModuleString *o = createStringObject(ptr,len);
if (ctx != NULL) autoMemoryAdd(ctx,REDISMODULE_AM_STRING,o);
return o;
}
/* Create a new module string object from a printf format and arguments.
* The returned string must be freed with RedisModule_FreeString(), unless
* automatic memory is enabled.
*
* The string is created using the sds formatter function sdscatvprintf().
*
* The passed context 'ctx' may be NULL if necessary, see the
* RedisModule_CreateString() documentation for more info. */
RedisModuleString *RM_CreateStringPrintf(RedisModuleCtx *ctx, const char *fmt, ...) {
sds s = sdsempty();
va_list ap;
va_start(ap, fmt);
s = sdscatvprintf(s, fmt, ap);
va_end(ap);
RedisModuleString *o = createObject(OBJ_STRING, s);
if (ctx != NULL) autoMemoryAdd(ctx,REDISMODULE_AM_STRING,o);
return o;
}
/* Like RedisModule_CreatString(), but creates a string starting from a long long
* integer instead of taking a buffer and its length.
*
* The returned string must be released with RedisModule_FreeString() or by
* enabling automatic memory management.
*
* The passed context 'ctx' may be NULL if necessary, see the
* RedisModule_CreateString() documentation for more info. */
RedisModuleString *RM_CreateStringFromLongLong(RedisModuleCtx *ctx, long long ll) {
char buf[LONG_STR_SIZE];
size_t len = ll2string(buf,sizeof(buf),ll);
return RM_CreateString(ctx,buf,len);
}
/* Like RedisModule_CreatString(), but creates a string starting from a double
* instead of taking a buffer and its length.
*
* The returned string must be released with RedisModule_FreeString() or by
* enabling automatic memory management. */
RedisModuleString *RM_CreateStringFromDouble(RedisModuleCtx *ctx, double d) {
char buf[128];
size_t len = d2string(buf,sizeof(buf),d);
return RM_CreateString(ctx,buf,len);
}
/* Like RedisModule_CreatString(), but creates a string starting from a long
* double.
*
* The returned string must be released with RedisModule_FreeString() or by
* enabling automatic memory management.
*
* The passed context 'ctx' may be NULL if necessary, see the
* RedisModule_CreateString() documentation for more info. */
RedisModuleString *RM_CreateStringFromLongDouble(RedisModuleCtx *ctx, long double ld, int humanfriendly) {
char buf[MAX_LONG_DOUBLE_CHARS];
size_t len = ld2string(buf,sizeof(buf),ld,
(humanfriendly ? LD_STR_HUMAN : LD_STR_AUTO));
return RM_CreateString(ctx,buf,len);
}
/* Like RedisModule_CreatString(), but creates a string starting from another
* RedisModuleString.
*
* The returned string must be released with RedisModule_FreeString() or by
* enabling automatic memory management.
*
* The passed context 'ctx' may be NULL if necessary, see the
* RedisModule_CreateString() documentation for more info. */
RedisModuleString *RM_CreateStringFromString(RedisModuleCtx *ctx, const RedisModuleString *str) {
RedisModuleString *o = dupStringObject(str);
if (ctx != NULL) autoMemoryAdd(ctx,REDISMODULE_AM_STRING,o);
return o;
}
/* Free a module string object obtained with one of the Redis modules API calls
* that return new string objects.
*
* It is possible to call this function even when automatic memory management
* is enabled. In that case the string will be released ASAP and removed
* from the pool of string to release at the end.
*
* If the string was created with a NULL context 'ctx', it is also possible to
* pass ctx as NULL when releasing the string (but passing a context will not
* create any issue). Strings created with a context should be freed also passing
* the context, so if you want to free a string out of context later, make sure
* to create it using a NULL context. */
void RM_FreeString(RedisModuleCtx *ctx, RedisModuleString *str) {
decrRefCount(str);
if (ctx != NULL) autoMemoryFreed(ctx,REDISMODULE_AM_STRING,str);
}
/* Every call to this function, will make the string 'str' requiring
* an additional call to RedisModule_FreeString() in order to really
* free the string. Note that the automatic freeing of the string obtained
* enabling modules automatic memory management counts for one
* RedisModule_FreeString() call (it is just executed automatically).
*
* Normally you want to call this function when, at the same time
* the following conditions are true:
*
* 1) You have automatic memory management enabled.
* 2) You want to create string objects.
* 3) Those string objects you create need to live *after* the callback
* function(for example a command implementation) creating them returns.
*
* Usually you want this in order to store the created string object
* into your own data structure, for example when implementing a new data
* type.
*
* Note that when memory management is turned off, you don't need
* any call to RetainString() since creating a string will always result
* into a string that lives after the callback function returns, if
* no FreeString() call is performed.
*
* It is possible to call this function with a NULL context. */
void RM_RetainString(RedisModuleCtx *ctx, RedisModuleString *str) {
if (ctx == NULL || !autoMemoryFreed(ctx,REDISMODULE_AM_STRING,str)) {
/* Increment the string reference counting only if we can't
* just remove the object from the list of objects that should
* be reclaimed. Why we do that, instead of just incrementing
* the refcount in any case, and let the automatic FreeString()
* call at the end to bring the refcount back at the desired
* value? Because this way we ensure that the object refcount
* value is 1 (instead of going to 2 to be dropped later to 1)
* after the call to this function. This is needed for functions
* like RedisModule_StringAppendBuffer() to work. */
incrRefCount(str);
}
}
/**
* This function can be used instead of RedisModule_RetainString().
* The main difference between the two is that this function will always
* succeed, whereas RedisModule_RetainString() may fail because of an
* assertion.
*
* The function returns a pointer to RedisModuleString, which is owned
* by the caller. It requires a call to RedisModule_FreeString() to free
* the string when automatic memory management is disabled for the context.
* When automatic memory management is enabled, you can either call
* RedisModule_FreeString() or let the automation free it.
*
* This function is more efficient than RedisModule_CreateStringFromString()
* because whenever possible, it avoids copying the underlying
* RedisModuleString. The disadvantage of using this function is that it
* might not be possible to use RedisModule_StringAppendBuffer() on the
* returned RedisModuleString.
*
* It is possible to call this function with a NULL context.
 */
RedisModuleString* RM_HoldString(RedisModuleCtx *ctx, RedisModuleString *str) {
if (str->refcount == OBJ_STATIC_REFCOUNT) {
return RM_CreateStringFromString(ctx, str);
}
incrRefCount(str);
if (ctx != NULL) {
/*
* Put the str in the auto memory management of the ctx.
         * It might already be there, in this case, the ref count will
         * be 2 and we will decrease the ref count twice and free the
         * object in the auto memory free function.
         *
         * Why we can not do the same trick of just remove the object
         * from the auto memory (like in RM_RetainString)?
         * This code shows the issue:
         *
         * RM_AutoMemory(ctx);
         * str1 = RM_CreateString(ctx, "test", 4);
         * str2 = RM_HoldString(ctx, str1);
         * RM_FreeString(str1);
         * RM_FreeString(str2);
         *
         * If after the RM_HoldString we would just remove the string from
         * the auto memory, this example will cause access to a freed memory
         * on 'RM_FreeString(str2);' because the String will be free
         * on 'RM_FreeString(str1);'.
         *
         * So it's safer to just increase the ref count
         * and add the String to auto memory again.
         *
         * The limitation is that it is not possible to use RedisModule_StringAppendBuffer
         * on the String.
*/
autoMemoryAdd(ctx,REDISMODULE_AM_STRING,str);
}
return str;
}
/* Given a string module object, this function returns the string pointer
* and length of the string. The returned pointer and length should only
* be used for read only accesses and never modified. */
const char *RM_StringPtrLen(const RedisModuleString *str, size_t *len) {
if (str == NULL) {
const char *errmsg = "(NULL string reply referenced in module)";
if (len) *len = strlen(errmsg);
return errmsg;
}
if (len) *len = sdslen(str->ptr);
return str->ptr;
}
/* --------------------------------------------------------------------------
* Higher level string operations
* ------------------------------------------------------------------------- */
/* Convert the string into a long long integer, storing it at `*ll`.
* Returns REDISMODULE_OK on success. If the string can't be parsed
* as a valid, strict long long (no spaces before/after), REDISMODULE_ERR
* is returned. */
int RM_StringToLongLong(const RedisModuleString *str, long long *ll) {
return string2ll(str->ptr,sdslen(str->ptr),ll) ? REDISMODULE_OK :
REDISMODULE_ERR;
}
/* Convert the string into a double, storing it at `*d`.
* Returns REDISMODULE_OK on success or REDISMODULE_ERR if the string is
* not a valid string representation of a double value. */
int RM_StringToDouble(const RedisModuleString *str, double *d) {
int retval = getDoubleFromObject(str,d);
return (retval == C_OK) ? REDISMODULE_OK : REDISMODULE_ERR;
}
/* Convert the string into a long double, storing it at `*ld`.
* Returns REDISMODULE_OK on success or REDISMODULE_ERR if the string is
* not a valid string representation of a double value. */
int RM_StringToLongDouble(const RedisModuleString *str, long double *ld) {
int retval = string2ld(str->ptr,sdslen(str->ptr),ld);
return retval ? REDISMODULE_OK : REDISMODULE_ERR;
}
/* Compare two string objects, returning -1, 0 or 1 respectively if
* a < b, a == b, a > b. Strings are compared byte by byte as two
* binary blobs without any encoding care / collation attempt. */
int RM_StringCompare(RedisModuleString *a, RedisModuleString *b) {
return compareStringObjects(a,b);
}
/* Return the (possibly modified in encoding) input 'str' object if
* the string is unshared, otherwise NULL is returned. */
RedisModuleString *moduleAssertUnsharedString(RedisModuleString *str) {
if (str->refcount != 1) {
serverLog(LL_WARNING,
"Module attempted to use an in-place string modify operation "
"with a string referenced multiple times. Please check the code "
"for API usage correctness.");
return NULL;
}
if (str->encoding == OBJ_ENCODING_EMBSTR) {
/* Note: here we "leak" the additional allocation that was
* used in order to store the embedded string in the object. */
str->ptr = sdsnewlen(str->ptr,sdslen(str->ptr));
str->encoding = OBJ_ENCODING_RAW;
} else if (str->encoding == OBJ_ENCODING_INT) {
/* Convert the string from integer to raw encoding. */
str->ptr = sdsfromlonglong((long)str->ptr);
str->encoding = OBJ_ENCODING_RAW;
}
return str;
}
/* Append the specified buffer to the string 'str'. The string must be a
* string created by the user that is referenced only a single time, otherwise
* REDISMODULE_ERR is returned and the operation is not performed. */
int RM_StringAppendBuffer(RedisModuleCtx *ctx, RedisModuleString *str, const char *buf, size_t len) {
UNUSED(ctx);
str = moduleAssertUnsharedString(str);
if (str == NULL) return REDISMODULE_ERR;
str->ptr = sdscatlen(str->ptr,buf,len);
return REDISMODULE_OK;
}
/* --------------------------------------------------------------------------
* Reply APIs
*
* Most functions always return REDISMODULE_OK so you can use it with
* 'return' in order to return from the command implementation with:
*
* if (... some condition ...)
* return RM_ReplyWithLongLong(ctx,mycount);
* -------------------------------------------------------------------------- */
/* Send an error about the number of arguments given to the command,
* citing the command name in the error message.
*
* Example:
*
* if (argc != 3) return RedisModule_WrongArity(ctx);
*/
int RM_WrongArity(RedisModuleCtx *ctx) {
addReplyErrorFormat(ctx->client,
"wrong number of arguments for '%s' command",
(char*)ctx->client->argv[0]->ptr);
return REDISMODULE_OK;
}
/* Return the client object the `RM_Reply*` functions should target.
* Normally this is just `ctx->client`, that is the client that called
* the module command, however in the case of thread safe contexts there
* is no directly associated client (since it would not be safe to access
* the client from a thread), so instead the blocked client object referenced
* in the thread safe context, has a fake client that we just use to accumulate
* the replies. Later, when the client is unblocked, the accumulated replies
* are appended to the actual client.
*
* The function returns the client pointer depending on the context, or
* NULL if there is no potential client. This happens when we are in the
* context of a thread safe context that was not initialized with a blocked
* client object. Other contexts without associated clients are the ones
* initialized to run the timers callbacks. */
client *moduleGetReplyClient(RedisModuleCtx *ctx) {
if (ctx->flags & REDISMODULE_CTX_THREAD_SAFE) {
if (ctx->blocked_client)
return ctx->blocked_client->reply_client;
else
return NULL;
} else {
/* If this is a non thread safe context, just return the client
* that is running the command if any. This may be NULL as well
* in the case of contexts that are not executed with associated
* clients, like timer contexts. */
return ctx->client;
}
}
/* Send an integer reply to the client, with the specified long long value.
* The function always returns REDISMODULE_OK. */
int RM_ReplyWithLongLong(RedisModuleCtx *ctx, long long ll) {
client *c = moduleGetReplyClient(ctx);
if (c == NULL) return REDISMODULE_OK;
addReplyLongLong(c,ll);
return REDISMODULE_OK;
}
/* Reply with an error or simple string (status message). Used to implement
* ReplyWithSimpleString() and ReplyWithError().
* The function always returns REDISMODULE_OK. */
int replyWithStatus(RedisModuleCtx *ctx, const char *msg, char *prefix) {
client *c = moduleGetReplyClient(ctx);
if (c == NULL) return REDISMODULE_OK;
addReplyProto(c,prefix,strlen(prefix));
addReplyProto(c,msg,strlen(msg));
addReplyProto(c,"\r\n",2);
return REDISMODULE_OK;
}
/* Reply with the error 'err'.
*
* Note that 'err' must contain all the error, including
* the initial error code. The function only provides the initial "-", so
* the usage is, for example:
*
* RedisModule_ReplyWithError(ctx,"ERR Wrong Type");
*
* and not just:
*
* RedisModule_ReplyWithError(ctx,"Wrong Type");
*
* The function always returns REDISMODULE_OK.
*/
int RM_ReplyWithError(RedisModuleCtx *ctx, const char *err) {
return replyWithStatus(ctx,err,"-");
}
/* Reply with a simple string (+... \r\n in RESP protocol). This replies
* are suitable only when sending a small non-binary string with small
* overhead, like "OK" or similar replies.
*
* The function always returns REDISMODULE_OK. */
int RM_ReplyWithSimpleString(RedisModuleCtx *ctx, const char *msg) {
return replyWithStatus(ctx,msg,"+");
}
/* Reply with an array type of 'len' elements. However 'len' other calls
* to `ReplyWith*` style functions must follow in order to emit the elements
* of the array.
*
* When producing arrays with a number of element that is not known beforehand
* the function can be called with the special count
* REDISMODULE_POSTPONED_ARRAY_LEN, and the actual number of elements can be
* later set with RedisModule_ReplySetArrayLength() (which will set the
* latest "open" count if there are multiple ones).
*
* The function always returns REDISMODULE_OK. */
int RM_ReplyWithArray(RedisModuleCtx *ctx, long len) {
client *c = moduleGetReplyClient(ctx);
if (c == NULL) return REDISMODULE_OK;
if (len == REDISMODULE_POSTPONED_ARRAY_LEN) {
ctx->postponed_arrays = zrealloc(ctx->postponed_arrays,sizeof(void*)*
(ctx->postponed_arrays_count+1));
ctx->postponed_arrays[ctx->postponed_arrays_count] =
addReplyDeferredLen(c);
ctx->postponed_arrays_count++;
} else {
addReplyArrayLen(c,len);
}
return REDISMODULE_OK;
}
/* Reply to the client with a null array, simply null in RESP3
* null array in RESP2.
*
* The function always returns REDISMODULE_OK. */
int RM_ReplyWithNullArray(RedisModuleCtx *ctx) {
client *c = moduleGetReplyClient(ctx);
if (c == NULL) return REDISMODULE_OK;
addReplyNullArray(c);
return REDISMODULE_OK;
}
/* Reply to the client with an empty array.
*
* The function always returns REDISMODULE_OK. */
int RM_ReplyWithEmptyArray(RedisModuleCtx *ctx) {
client *c = moduleGetReplyClient(ctx);
if (c == NULL) return REDISMODULE_OK;
addReply(c,shared.emptyarray);
return REDISMODULE_OK;
}
/* When RedisModule_ReplyWithArray() is used with the argument
* REDISMODULE_POSTPONED_ARRAY_LEN, because we don't know beforehand the number
* of items we are going to output as elements of the array, this function
* will take care to set the array length.
*
* Since it is possible to have multiple array replies pending with unknown
* length, this function guarantees to always set the latest array length
* that was created in a postponed way.
*
* For example in order to output an array like [1,[10,20,30]] we
* could write:
*
* RedisModule_ReplyWithArray(ctx,REDISMODULE_POSTPONED_ARRAY_LEN);
* RedisModule_ReplyWithLongLong(ctx,1);
* RedisModule_ReplyWithArray(ctx,REDISMODULE_POSTPONED_ARRAY_LEN);
* RedisModule_ReplyWithLongLong(ctx,10);
* RedisModule_ReplyWithLongLong(ctx,20);
* RedisModule_ReplyWithLongLong(ctx,30);
* RedisModule_ReplySetArrayLength(ctx,3); // Set len of 10,20,30 array.
* RedisModule_ReplySetArrayLength(ctx,2); // Set len of top array
*
* Note that in the above example there is no reason to postpone the array
* length, since we produce a fixed number of elements, but in the practice
* the code may use an iterator or other ways of creating the output so
* that is not easy to calculate in advance the number of elements.
*/
void RM_ReplySetArrayLength(RedisModuleCtx *ctx, long len) {
client *c = moduleGetReplyClient(ctx);
if (c == NULL) return;
if (ctx->postponed_arrays_count == 0) {
serverLog(LL_WARNING,
"API misuse detected in module %s: "
"RedisModule_ReplySetArrayLength() called without previous "
"RedisModule_ReplyWithArray(ctx,REDISMODULE_POSTPONED_ARRAY_LEN) "
"call.", ctx->module->name);
return;
}
ctx->postponed_arrays_count--;
setDeferredArrayLen(c,
ctx->postponed_arrays[ctx->postponed_arrays_count],
len);
if (ctx->postponed_arrays_count == 0) {
zfree(ctx->postponed_arrays);
ctx->postponed_arrays = NULL;
}
}
/* Reply with a bulk string, taking in input a C buffer pointer and length.
*
* The function always returns REDISMODULE_OK. */
int RM_ReplyWithStringBuffer(RedisModuleCtx *ctx, const char *buf, size_t len) {
client *c = moduleGetReplyClient(ctx);
if (c == NULL) return REDISMODULE_OK;
addReplyBulkCBuffer(c,(char*)buf,len);
return REDISMODULE_OK;
}
/* Reply with a bulk string, taking in input a C buffer pointer that is
* assumed to be null-terminated.
*
* The function always returns REDISMODULE_OK. */
int RM_ReplyWithCString(RedisModuleCtx *ctx, const char *buf) {
client *c = moduleGetReplyClient(ctx);
if (c == NULL) return REDISMODULE_OK;
addReplyBulkCString(c,(char*)buf);
return REDISMODULE_OK;
}
/* Reply with a bulk string, taking in input a RedisModuleString object.
*
* The function always returns REDISMODULE_OK. */
int RM_ReplyWithString(RedisModuleCtx *ctx, RedisModuleString *str) {
client *c = moduleGetReplyClient(ctx);
if (c == NULL) return REDISMODULE_OK;
addReplyBulk(c,str);
return REDISMODULE_OK;
}
/* Reply with an empty string.
*
* The function always returns REDISMODULE_OK. */
int RM_ReplyWithEmptyString(RedisModuleCtx *ctx) {
client *c = moduleGetReplyClient(ctx);
if (c == NULL) return REDISMODULE_OK;
addReply(c,shared.emptybulk);
return REDISMODULE_OK;
}
/* Reply with a binary safe string, which should not be escaped or filtered
* taking in input a C buffer pointer and length.
*
* The function always returns REDISMODULE_OK. */
int RM_ReplyWithVerbatimString(RedisModuleCtx *ctx, const char *buf, size_t len) {
client *c = moduleGetReplyClient(ctx);
if (c == NULL) return REDISMODULE_OK;
addReplyVerbatim(c, buf, len, "txt");
return REDISMODULE_OK;
}
/* Reply to the client with a NULL.
*
* The function always returns REDISMODULE_OK. */
int RM_ReplyWithNull(RedisModuleCtx *ctx) {
client *c = moduleGetReplyClient(ctx);
if (c == NULL) return REDISMODULE_OK;
addReplyNull(c);
return REDISMODULE_OK;
}
/* Reply exactly what a Redis command returned us with RedisModule_Call().
* This function is useful when we use RedisModule_Call() in order to
* execute some command, as we want to reply to the client exactly the
* same reply we obtained by the command.
*
* The function always returns REDISMODULE_OK. */
int RM_ReplyWithCallReply(RedisModuleCtx *ctx, RedisModuleCallReply *reply) {
client *c = moduleGetReplyClient(ctx);
if (c == NULL) return REDISMODULE_OK;
sds proto = sdsnewlen(reply->proto, reply->protolen);
addReplySds(c,proto);
return REDISMODULE_OK;
}
/* Send a string reply obtained converting the double 'd' into a bulk string.
* This function is basically equivalent to converting a double into
* a string into a C buffer, and then calling the function
* RedisModule_ReplyWithStringBuffer() with the buffer and length.
*
* The function always returns REDISMODULE_OK. */
int RM_ReplyWithDouble(RedisModuleCtx *ctx, double d) {
client *c = moduleGetReplyClient(ctx);
if (c == NULL) return REDISMODULE_OK;
addReplyDouble(c,d);
return REDISMODULE_OK;
}
/* Send a string reply obtained converting the long double 'ld' into a bulk
* string. This function is basically equivalent to converting a long double
* into a string into a C buffer, and then calling the function
* RedisModule_ReplyWithStringBuffer() with the buffer and length.
* The double string uses human readable formatting (see
* `addReplyHumanLongDouble` in networking.c).
*
* The function always returns REDISMODULE_OK. */
int RM_ReplyWithLongDouble(RedisModuleCtx *ctx, long double ld) {
client *c = moduleGetReplyClient(ctx);
if (c == NULL) return REDISMODULE_OK;
addReplyHumanLongDouble(c, ld);
return REDISMODULE_OK;
}
/* --------------------------------------------------------------------------
* Commands replication API
* -------------------------------------------------------------------------- */
/* Helper function to replicate MULTI the first time we replicate something
* in the context of a command execution. EXEC will be handled by the
* RedisModuleCommandDispatcher() function. */
void moduleReplicateMultiIfNeeded(RedisModuleCtx *ctx) {
/* Skip this if client explicitly wrap the command with MULTI, or if
* the module command was called by a script. */
if (ctx->client->flags & (CLIENT_MULTI|CLIENT_LUA)) return;
/* If we already emitted MULTI return ASAP. */
if (ctx->flags & REDISMODULE_CTX_MULTI_EMITTED) return;
/* If this is a thread safe context, we do not want to wrap commands
* executed into MULTI/EXEC, they are executed as single commands
* from an external client in essence. */
if (ctx->flags & REDISMODULE_CTX_THREAD_SAFE) return;
/* If this is a callback context, and not a module command execution
* context, we have to setup the op array for the "also propagate" API
* so that RM_Replicate() will work. */
if (!(ctx->flags & REDISMODULE_CTX_MODULE_COMMAND_CALL)) {
ctx->saved_oparray = server.also_propagate;
redisOpArrayInit(&server.also_propagate);
}
execCommandPropagateMulti(ctx->client);
ctx->flags |= REDISMODULE_CTX_MULTI_EMITTED;
}
/* Replicate the specified command and arguments to slaves and AOF, as effect
* of execution of the calling command implementation.
*
* The replicated commands are always wrapped into the MULTI/EXEC that
* contains all the commands replicated in a given module command
* execution. However the commands replicated with RedisModule_Call()
* are the first items, the ones replicated with RedisModule_Replicate()
* will all follow before the EXEC.
*
* Modules should try to use one interface or the other.
*
* This command follows exactly the same interface of RedisModule_Call(),
* so a set of format specifiers must be passed, followed by arguments
* matching the provided format specifiers.
*
* Please refer to RedisModule_Call() for more information.
*
* Using the special "A" and "R" modifiers, the caller can exclude either
* the AOF or the replicas from the propagation of the specified command.
* Otherwise, by default, the command will be propagated in both channels.
*
* ## Note about calling this function from a thread safe context:
*
* Normally when you call this function from the callback implementing a
* module command, or any other callback provided by the Redis Module API,
* Redis will accumulate all the calls to this function in the context of
* the callback, and will propagate all the commands wrapped in a MULTI/EXEC
* transaction. However when calling this function from a threaded safe context
* that can live an undefined amount of time, and can be locked/unlocked in
* at will, the behavior is different: MULTI/EXEC wrapper is not emitted
* and the command specified is inserted in the AOF and replication stream
* immediately.
*
* ## Return value
*
* The command returns REDISMODULE_ERR if the format specifiers are invalid
* or the command name does not belong to a known command. */
int RM_Replicate(RedisModuleCtx *ctx, const char *cmdname, const char *fmt, ...) {
struct redisCommand *cmd;
robj **argv = NULL;
int argc = 0, flags = 0, j;
va_list ap;
cmd = lookupCommandByCString((char*)cmdname);
if (!cmd) return REDISMODULE_ERR;
/* Create the client and dispatch the command. */
va_start(ap, fmt);
argv = moduleCreateArgvFromUserFormat(cmdname,fmt,&argc,&flags,ap);
va_end(ap);
if (argv == NULL) return REDISMODULE_ERR;
/* Select the propagation target. Usually is AOF + replicas, however
* the caller can exclude one or the other using the "A" or "R"
* modifiers. */
int target = 0;
if (!(flags & REDISMODULE_ARGV_NO_AOF)) target |= PROPAGATE_AOF;
if (!(flags & REDISMODULE_ARGV_NO_REPLICAS)) target |= PROPAGATE_REPL;
/* Replicate! When we are in a threaded context, we want to just insert
* the replicated command ASAP, since it is not clear when the context
* will stop being used, so accumulating stuff does not make much sense,
* nor we could easily use the alsoPropagate() API from threads. */
if (ctx->flags & REDISMODULE_CTX_THREAD_SAFE) {
propagate(cmd,ctx->client->db->id,argv,argc,target);
} else {
moduleReplicateMultiIfNeeded(ctx);
alsoPropagate(cmd,ctx->client->db->id,argv,argc,target);
}
/* Release the argv. */
for (j = 0; j < argc; j++) decrRefCount(argv[j]);
zfree(argv);
server.dirty++;
return REDISMODULE_OK;
}
/* This function will replicate the command exactly as it was invoked
* by the client. Note that this function will not wrap the command into
* a MULTI/EXEC stanza, so it should not be mixed with other replication
* commands.
*
* Basically this form of replication is useful when you want to propagate
* the command to the slaves and AOF file exactly as it was called, since
* the command can just be re-executed to deterministically re-create the
* new state starting from the old one.
*
* The function always returns REDISMODULE_OK. */
int RM_ReplicateVerbatim(RedisModuleCtx *ctx) {
alsoPropagate(ctx->client->cmd,ctx->client->db->id,
ctx->client->argv,ctx->client->argc,
PROPAGATE_AOF|PROPAGATE_REPL);
server.dirty++;
return REDISMODULE_OK;
}
/* --------------------------------------------------------------------------
* DB and Key APIs -- Generic API
* -------------------------------------------------------------------------- */
/* Return the ID of the current client calling the currently active module
* command. The returned ID has a few guarantees:
*
* 1. The ID is different for each different client, so if the same client
* executes a module command multiple times, it can be recognized as
* having the same ID, otherwise the ID will be different.
* 2. The ID increases monotonically. Clients connecting to the server later
* are guaranteed to get IDs greater than any past ID previously seen.
*
* Valid IDs are from 1 to 2^64-1. If 0 is returned it means there is no way
* to fetch the ID in the context the function was currently called.
*
* After obtaining the ID, it is possible to check if the command execution
* is actually happening in the context of AOF loading, using this macro:
*
* if (RedisModule_IsAOFClient(RedisModule_GetClientId(ctx)) {
* // Handle it differently.
* }
*/
unsigned long long RM_GetClientId(RedisModuleCtx *ctx) {
if (ctx->client == NULL) return 0;
return ctx->client->id;
}
/* This is an helper for RM_GetClientInfoById() and other functions: given
* a client, it populates the client info structure with the appropriate
* fields depending on the version provided. If the version is not valid
* then REDISMODULE_ERR is returned. Otherwise the function returns
* REDISMODULE_OK and the structure pointed by 'ci' gets populated. */
int modulePopulateClientInfoStructure(void *ci, client *client, int structver) {
if (structver != 1) return REDISMODULE_ERR;
RedisModuleClientInfoV1 *ci1 = ci;
memset(ci1,0,sizeof(*ci1));
ci1->version = structver;
if (client->flags & CLIENT_MULTI)
ci1->flags |= REDISMODULE_CLIENTINFO_FLAG_MULTI;
if (client->flags & CLIENT_PUBSUB)
ci1->flags |= REDISMODULE_CLIENTINFO_FLAG_PUBSUB;
if (client->flags & CLIENT_UNIX_SOCKET)
ci1->flags |= REDISMODULE_CLIENTINFO_FLAG_UNIXSOCKET;
if (client->flags & CLIENT_TRACKING)
ci1->flags |= REDISMODULE_CLIENTINFO_FLAG_TRACKING;
if (client->flags & CLIENT_BLOCKED)
ci1->flags |= REDISMODULE_CLIENTINFO_FLAG_BLOCKED;
if (connGetType(client->conn) == CONN_TYPE_TLS)
ci1->flags |= REDISMODULE_CLIENTINFO_FLAG_SSL;
int port;
connPeerToString(client->conn,ci1->addr,sizeof(ci1->addr),&port);
ci1->port = port;
ci1->db = client->db->id;
ci1->id = client->id;
return REDISMODULE_OK;
}
/* This is an helper for moduleFireServerEvent() and other functions:
* It populates the replication info structure with the appropriate
* fields depending on the version provided. If the version is not valid
* then REDISMODULE_ERR is returned. Otherwise the function returns
* REDISMODULE_OK and the structure pointed by 'ri' gets populated. */
int modulePopulateReplicationInfoStructure(void *ri, int structver) {
if (structver != 1) return REDISMODULE_ERR;
RedisModuleReplicationInfoV1 *ri1 = ri;
memset(ri1,0,sizeof(*ri1));
ri1->version = structver;
ri1->master = server.masterhost==NULL;
ri1->masterhost = server.masterhost? server.masterhost: "";
ri1->masterport = server.masterport;
ri1->replid1 = server.replid;
ri1->replid2 = server.replid2;
ri1->repl1_offset = server.master_repl_offset;
ri1->repl2_offset = server.second_replid_offset;
return REDISMODULE_OK;
}
/* Return information about the client with the specified ID (that was
* previously obtained via the RedisModule_GetClientId() API). If the
* client exists, REDISMODULE_OK is returned, otherwise REDISMODULE_ERR
* is returned.
*
* When the client exist and the `ci` pointer is not NULL, but points to
* a structure of type RedisModuleClientInfo, previously initialized with
* the correct REDISMODULE_CLIENTINFO_INITIALIZER, the structure is populated
* with the following fields:
*
* uint64_t flags; // REDISMODULE_CLIENTINFO_FLAG_*
* uint64_t id; // Client ID
* char addr[46]; // IPv4 or IPv6 address.
* uint16_t port; // TCP port.
* uint16_t db; // Selected DB.
*
* Note: the client ID is useless in the context of this call, since we
* already know, however the same structure could be used in other
* contexts where we don't know the client ID, yet the same structure
* is returned.
*
* With flags having the following meaning:
*
* REDISMODULE_CLIENTINFO_FLAG_SSL Client using SSL connection.
* REDISMODULE_CLIENTINFO_FLAG_PUBSUB Client in Pub/Sub mode.
* REDISMODULE_CLIENTINFO_FLAG_BLOCKED Client blocked in command.
* REDISMODULE_CLIENTINFO_FLAG_TRACKING Client with keys tracking on.
* REDISMODULE_CLIENTINFO_FLAG_UNIXSOCKET Client using unix domain socket.
* REDISMODULE_CLIENTINFO_FLAG_MULTI Client in MULTI state.
*
* However passing NULL is a way to just check if the client exists in case
* we are not interested in any additional information.
*
* This is the correct usage when we want the client info structure
* returned:
*
* RedisModuleClientInfo ci = REDISMODULE_CLIENTINFO_INITIALIZER;
* int retval = RedisModule_GetClientInfoById(&ci,client_id);
* if (retval == REDISMODULE_OK) {
* printf("Address: %s\n", ci.addr);
* }
*/
int RM_GetClientInfoById(void *ci, uint64_t id) {
client *client = lookupClientByID(id);
if (client == NULL) return REDISMODULE_ERR;
if (ci == NULL) return REDISMODULE_OK;
/* Fill the info structure if passed. */
uint64_t structver = ((uint64_t*)ci)[0];
return modulePopulateClientInfoStructure(ci,client,structver);
}
/* Publish a message to subscribers (see PUBLISH command). */
int RM_PublishMessage(RedisModuleCtx *ctx, RedisModuleString *channel, RedisModuleString *message) {
UNUSED(ctx);
int receivers = pubsubPublishMessage(channel, message);
if (server.cluster_enabled)
clusterPropagatePublish(channel, message);
return receivers;
}
/* Return the currently selected DB. */
int RM_GetSelectedDb(RedisModuleCtx *ctx) {
return ctx->client->db->id;
}
/* Return the current context's flags. The flags provide information on the
* current request context (whether the client is a Lua script or in a MULTI),
* and about the Redis instance in general, i.e replication and persistence.
*
* It is possible to call this function even with a NULL context, however
* in this case the following flags will not be reported:
*
* * LUA, MULTI, REPLICATED, DIRTY (see below for more info).
*
* Available flags and their meaning:
*
* * REDISMODULE_CTX_FLAGS_LUA: The command is running in a Lua script
*
* * REDISMODULE_CTX_FLAGS_MULTI: The command is running inside a transaction
*
* * REDISMODULE_CTX_FLAGS_REPLICATED: The command was sent over the replication
* link by the MASTER
*
* * REDISMODULE_CTX_FLAGS_MASTER: The Redis instance is a master
*
* * REDISMODULE_CTX_FLAGS_SLAVE: The Redis instance is a slave
*
* * REDISMODULE_CTX_FLAGS_READONLY: The Redis instance is read-only
*
* * REDISMODULE_CTX_FLAGS_CLUSTER: The Redis instance is in cluster mode
*
* * REDISMODULE_CTX_FLAGS_AOF: The Redis instance has AOF enabled
*
* * REDISMODULE_CTX_FLAGS_RDB: The instance has RDB enabled
*
* * REDISMODULE_CTX_FLAGS_MAXMEMORY: The instance has Maxmemory set
*
* * REDISMODULE_CTX_FLAGS_EVICT: Maxmemory is set and has an eviction
* policy that may delete keys
*
* * REDISMODULE_CTX_FLAGS_OOM: Redis is out of memory according to the
* maxmemory setting.
*
* * REDISMODULE_CTX_FLAGS_OOM_WARNING: Less than 25% of memory remains before
* reaching the maxmemory level.
*
* * REDISMODULE_CTX_FLAGS_LOADING: Server is loading RDB/AOF
*
* * REDISMODULE_CTX_FLAGS_REPLICA_IS_STALE: No active link with the master.
*
* * REDISMODULE_CTX_FLAGS_REPLICA_IS_CONNECTING: The replica is trying to
* connect with the master.
*
* * REDISMODULE_CTX_FLAGS_REPLICA_IS_TRANSFERRING: Master -> Replica RDB
* transfer is in progress.
*
* * REDISMODULE_CTX_FLAGS_REPLICA_IS_ONLINE: The replica has an active link
* with its master. This is the
* contrary of STALE state.
*
* * REDISMODULE_CTX_FLAGS_ACTIVE_CHILD: There is currently some background
* process active (RDB, AUX or module).
*
* * REDISMODULE_CTX_FLAGS_MULTI_DIRTY: The next EXEC will fail due to dirty
* CAS (touched keys).
*
* * REDISMODULE_CTX_FLAGS_IS_CHILD: Redis is currently running inside
* background child process.
*/
int RM_GetContextFlags(RedisModuleCtx *ctx) {
int flags = 0;
/* Client specific flags */
if (ctx) {
if (ctx->client) {
if (ctx->client->flags & CLIENT_LUA)
flags |= REDISMODULE_CTX_FLAGS_LUA;
if (ctx->client->flags & CLIENT_MULTI)
flags |= REDISMODULE_CTX_FLAGS_MULTI;
/* Module command received from MASTER, is replicated. */
if (ctx->client->flags & CLIENT_MASTER)
flags |= REDISMODULE_CTX_FLAGS_REPLICATED;
}
/* For DIRTY flags, we need the blocked client if used */
client *c = ctx->blocked_client ? ctx->blocked_client->client : ctx->client;
if (c && (c->flags & (CLIENT_DIRTY_CAS|CLIENT_DIRTY_EXEC))) {
flags |= REDISMODULE_CTX_FLAGS_MULTI_DIRTY;
}
}
if (server.cluster_enabled)
flags |= REDISMODULE_CTX_FLAGS_CLUSTER;
if (server.loading)
flags |= REDISMODULE_CTX_FLAGS_LOADING;
/* Maxmemory and eviction policy */
if (server.maxmemory > 0) {
flags |= REDISMODULE_CTX_FLAGS_MAXMEMORY;
if (server.maxmemory_policy != MAXMEMORY_NO_EVICTION)
flags |= REDISMODULE_CTX_FLAGS_EVICT;
}
/* Persistence flags */
if (server.aof_state != AOF_OFF)
flags |= REDISMODULE_CTX_FLAGS_AOF;
if (server.saveparamslen > 0)
flags |= REDISMODULE_CTX_FLAGS_RDB;
/* Replication flags */
if (server.masterhost == NULL) {
flags |= REDISMODULE_CTX_FLAGS_MASTER;
} else {
flags |= REDISMODULE_CTX_FLAGS_SLAVE;
if (server.repl_slave_ro)
flags |= REDISMODULE_CTX_FLAGS_READONLY;
/* Replica state flags. */
if (server.repl_state == REPL_STATE_CONNECT ||
server.repl_state == REPL_STATE_CONNECTING)
{
flags |= REDISMODULE_CTX_FLAGS_REPLICA_IS_CONNECTING;
} else if (server.repl_state == REPL_STATE_TRANSFER) {
flags |= REDISMODULE_CTX_FLAGS_REPLICA_IS_TRANSFERRING;
} else if (server.repl_state == REPL_STATE_CONNECTED) {
flags |= REDISMODULE_CTX_FLAGS_REPLICA_IS_ONLINE;
}
if (server.repl_state != REPL_STATE_CONNECTED)
flags |= REDISMODULE_CTX_FLAGS_REPLICA_IS_STALE;
}
/* OOM flag. */
float level;
int retval = getMaxmemoryState(NULL,NULL,NULL,&level);
if (retval == C_ERR) flags |= REDISMODULE_CTX_FLAGS_OOM;
if (level > 0.75) flags |= REDISMODULE_CTX_FLAGS_OOM_WARNING;
/* Presence of children processes. */
if (hasActiveChildProcess()) flags |= REDISMODULE_CTX_FLAGS_ACTIVE_CHILD;
if (server.in_fork_child) flags |= REDISMODULE_CTX_FLAGS_IS_CHILD;
return flags;
}
/* Returns true if some client sent the CLIENT PAUSE command to the server or
* if Redis Cluster is doing a manual failover, and paused tue clients.
* This is needed when we have a master with replicas, and want to write,
* without adding further data to the replication channel, that the replicas
* replication offset, match the one of the master. When this happens, it is
* safe to failover the master without data loss.
*
* However modules may generate traffic by calling RedisModule_Call() with
* the "!" flag, or by calling RedisModule_Replicate(), in a context outside
* commands execution, for instance in timeout callbacks, threads safe
* contexts, and so forth. When modules will generate too much traffic, it
* will be hard for the master and replicas offset to match, because there
* is more data to send in the replication channel.
*
* So modules may want to try to avoid very heavy background work that has
* the effect of creating data to the replication channel, when this function
* returns true. This is mostly useful for modules that have background
* garbage collection tasks, or that do writes and replicate such writes
* periodically in timer callbacks or other periodic callbacks.
*/
int RM_AvoidReplicaTraffic() {
return clientsArePaused();
}
/* Change the currently selected DB. Returns an error if the id
* is out of range.
*
* Note that the client will retain the currently selected DB even after
* the Redis command implemented by the module calling this function
* returns.
*
* If the module command wishes to change something in a different DB and
* returns back to the original one, it should call RedisModule_GetSelectedDb()
* before in order to restore the old DB number before returning. */
int RM_SelectDb(RedisModuleCtx *ctx, int newid) {
int retval = selectDb(ctx->client,newid);
return (retval == C_OK) ? REDISMODULE_OK : REDISMODULE_ERR;
}
/* Initialize a RedisModuleKey struct */
static void moduleInitKey(RedisModuleKey *kp, RedisModuleCtx *ctx, robj *keyname, robj *value, int mode){
kp->ctx = ctx;
kp->db = ctx->client->db;
kp->key = keyname;
incrRefCount(keyname);
kp->value = value;
kp->iter = NULL;
kp->mode = mode;
zsetKeyReset(kp);
}
/* Return an handle representing a Redis key, so that it is possible
* to call other APIs with the key handle as argument to perform
* operations on the key.
*
* The return value is the handle representing the key, that must be
* closed with RM_CloseKey().
*
* If the key does not exist and WRITE mode is requested, the handle
* is still returned, since it is possible to perform operations on
* a yet not existing key (that will be created, for example, after
* a list push operation). If the mode is just READ instead, and the
* key does not exist, NULL is returned. However it is still safe to
* call RedisModule_CloseKey() and RedisModule_KeyType() on a NULL
* value. */
void *RM_OpenKey(RedisModuleCtx *ctx, robj *keyname, int mode) {
RedisModuleKey *kp;
robj *value;
int flags = mode & REDISMODULE_OPEN_KEY_NOTOUCH? LOOKUP_NOTOUCH: 0;
if (mode & REDISMODULE_WRITE) {
value = lookupKeyWriteWithFlags(ctx->client->db,keyname, flags);
} else {
value = lookupKeyReadWithFlags(ctx->client->db,keyname, flags);
if (value == NULL) {
return NULL;
}
}
/* Setup the key handle. */
kp = zmalloc(sizeof(*kp));
moduleInitKey(kp, ctx, keyname, value, mode);
autoMemoryAdd(ctx,REDISMODULE_AM_KEY,kp);
return (void*)kp;
}
/* Destroy a RedisModuleKey struct (freeing is the responsibility of the caller). */
static void moduleCloseKey(RedisModuleKey *key) {
int signal = SHOULD_SIGNAL_MODIFIED_KEYS(key->ctx);
if ((key->mode & REDISMODULE_WRITE) && signal)
signalModifiedKey(key->ctx->client,key->db,key->key);
/* TODO: if (key->iter) RM_KeyIteratorStop(kp); */
RM_ZsetRangeStop(key);
decrRefCount(key->key);
}
/* Close a key handle. */
void RM_CloseKey(RedisModuleKey *key) {
if (key == NULL) return;
moduleCloseKey(key);
autoMemoryFreed(key->ctx,REDISMODULE_AM_KEY,key);
zfree(key);
}
/* Return the type of the key. If the key pointer is NULL then
* REDISMODULE_KEYTYPE_EMPTY is returned. */
int RM_KeyType(RedisModuleKey *key) {
if (key == NULL || key->value == NULL) return REDISMODULE_KEYTYPE_EMPTY;
/* We map between defines so that we are free to change the internal
* defines as desired. */
switch(key->value->type) {
case OBJ_STRING: return REDISMODULE_KEYTYPE_STRING;
case OBJ_LIST: return REDISMODULE_KEYTYPE_LIST;
case OBJ_SET: return REDISMODULE_KEYTYPE_SET;
case OBJ_ZSET: return REDISMODULE_KEYTYPE_ZSET;
case OBJ_HASH: return REDISMODULE_KEYTYPE_HASH;
case OBJ_MODULE: return REDISMODULE_KEYTYPE_MODULE;
case OBJ_STREAM: return REDISMODULE_KEYTYPE_STREAM;
default: return REDISMODULE_KEYTYPE_EMPTY;
}
}
/* Return the length of the value associated with the key.
* For strings this is the length of the string. For all the other types
* is the number of elements (just counting keys for hashes).
*
* If the key pointer is NULL or the key is empty, zero is returned. */
size_t RM_ValueLength(RedisModuleKey *key) {
if (key == NULL || key->value == NULL) return 0;
switch(key->value->type) {
case OBJ_STRING: return stringObjectLen(key->value);
case OBJ_LIST: return listTypeLength(key->value);
case OBJ_SET: return setTypeSize(key->value);
case OBJ_ZSET: return zsetLength(key->value);
case OBJ_HASH: return hashTypeLength(key->value);
case OBJ_STREAM: return streamLength(key->value);
default: return 0;
}
}
/* If the key is open for writing, remove it, and setup the key to
* accept new writes as an empty key (that will be created on demand).
* On success REDISMODULE_OK is returned. If the key is not open for
* writing REDISMODULE_ERR is returned. */
int RM_DeleteKey(RedisModuleKey *key) {
if (!(key->mode & REDISMODULE_WRITE)) return REDISMODULE_ERR;
if (key->value) {
dbDelete(key->db,key->key);
key->value = NULL;
}
return REDISMODULE_OK;
}
/* If the key is open for writing, unlink it (that is delete it in a
* non-blocking way, not reclaiming memory immediately) and setup the key to
* accept new writes as an empty key (that will be created on demand).
* On success REDISMODULE_OK is returned. If the key is not open for
* writing REDISMODULE_ERR is returned. */
int RM_UnlinkKey(RedisModuleKey *key) {
if (!(key->mode & REDISMODULE_WRITE)) return REDISMODULE_ERR;
if (key->value) {
dbAsyncDelete(key->db,key->key);
key->value = NULL;
}
return REDISMODULE_OK;
}
/* Return the key expire value, as milliseconds of remaining TTL.
* If no TTL is associated with the key or if the key is empty,
* REDISMODULE_NO_EXPIRE is returned. */
mstime_t RM_GetExpire(RedisModuleKey *key) {
mstime_t expire = getExpire(key->db,key->key);
if (expire == -1 || key->value == NULL)
return REDISMODULE_NO_EXPIRE;
expire -= mstime();
return expire >= 0 ? expire : 0;
}
/* Set a new expire for the key. If the special expire
* REDISMODULE_NO_EXPIRE is set, the expire is cancelled if there was
* one (the same as the PERSIST command).
*
* Note that the expire must be provided as a positive integer representing
* the number of milliseconds of TTL the key should have.
*
* The function returns REDISMODULE_OK on success or REDISMODULE_ERR if
* the key was not open for writing or is an empty key. */
int RM_SetExpire(RedisModuleKey *key, mstime_t expire) {
if (!(key->mode & REDISMODULE_WRITE) || key->value == NULL)
return REDISMODULE_ERR;
if (expire != REDISMODULE_NO_EXPIRE) {
expire += mstime();
setExpire(key->ctx->client,key->db,key->key,expire);
} else {
removeExpire(key->db,key->key);
}
return REDISMODULE_OK;
}
/* Performs similar operation to FLUSHALL, and optionally start a new AOF file (if enabled)
* If restart_aof is true, you must make sure the command that triggered this call is not
* propagated to the AOF file.
* When async is set to true, db contents will be freed by a background thread. */
void RM_ResetDataset(int restart_aof, int async) {
if (restart_aof && server.aof_state != AOF_OFF) stopAppendOnly();
flushAllDataAndResetRDB(async? EMPTYDB_ASYNC: EMPTYDB_NO_FLAGS);
if (server.aof_enabled && restart_aof) restartAOFAfterSYNC();
}
/* Returns the number of keys in the current db. */
unsigned long long RM_DbSize(RedisModuleCtx *ctx) {
return dictSize(ctx->client->db->dict);
}
/* Returns a name of a random key, or NULL if current db is empty. */
RedisModuleString *RM_RandomKey(RedisModuleCtx *ctx) {
robj *key = dbRandomKey(ctx->client->db);
autoMemoryAdd(ctx,REDISMODULE_AM_STRING,key);
return key;
}
/* --------------------------------------------------------------------------
* Key API for String type
* -------------------------------------------------------------------------- */
/* If the key is open for writing, set the specified string 'str' as the
* value of the key, deleting the old value if any.
* On success REDISMODULE_OK is returned. If the key is not open for
* writing or there is an active iterator, REDISMODULE_ERR is returned. */
int RM_StringSet(RedisModuleKey *key, RedisModuleString *str) {
if (!(key->mode & REDISMODULE_WRITE) || key->iter) return REDISMODULE_ERR;
RM_DeleteKey(key);
genericSetKey(key->ctx->client,key->db,key->key,str,0,0);
key->value = str;
return REDISMODULE_OK;
}
/* Prepare the key associated string value for DMA access, and returns
* a pointer and size (by reference), that the user can use to read or
* modify the string in-place accessing it directly via pointer.
*
* The 'mode' is composed by bitwise OR-ing the following flags:
*
* REDISMODULE_READ -- Read access
* REDISMODULE_WRITE -- Write access
*
* If the DMA is not requested for writing, the pointer returned should
* only be accessed in a read-only fashion.
*
* On error (wrong type) NULL is returned.
*
* DMA access rules:
*
* 1. No other key writing function should be called since the moment
* the pointer is obtained, for all the time we want to use DMA access
* to read or modify the string.
*
* 2. Each time RM_StringTruncate() is called, to continue with the DMA
* access, RM_StringDMA() should be called again to re-obtain
* a new pointer and length.
*
* 3. If the returned pointer is not NULL, but the length is zero, no
* byte can be touched (the string is empty, or the key itself is empty)
* so a RM_StringTruncate() call should be used if there is to enlarge
* the string, and later call StringDMA() again to get the pointer.
*/
char *RM_StringDMA(RedisModuleKey *key, size_t *len, int mode) {
/* We need to return *some* pointer for empty keys, we just return
* a string literal pointer, that is the advantage to be mapped into
* a read only memory page, so the module will segfault if a write
* attempt is performed. */
char *emptystring = "<dma-empty-string>";
if (key->value == NULL) {
*len = 0;
return emptystring;
}
if (key->value->type != OBJ_STRING) return NULL;
/* For write access, and even for read access if the object is encoded,
* we unshare the string (that has the side effect of decoding it). */
if ((mode & REDISMODULE_WRITE) || key->value->encoding != OBJ_ENCODING_RAW)
key->value = dbUnshareStringValue(key->db, key->key, key->value);
*len = sdslen(key->value->ptr);
return key->value->ptr;
}
/* If the string is open for writing and is of string type, resize it, padding
* with zero bytes if the new length is greater than the old one.
*
* After this call, RM_StringDMA() must be called again to continue
* DMA access with the new pointer.
*
* The function returns REDISMODULE_OK on success, and REDISMODULE_ERR on
* error, that is, the key is not open for writing, is not a string
* or resizing for more than 512 MB is requested.
*
* If the key is empty, a string key is created with the new string value
* unless the new length value requested is zero. */
int RM_StringTruncate(RedisModuleKey *key, size_t newlen) {
if (!(key->mode & REDISMODULE_WRITE)) return REDISMODULE_ERR;
if (key->value && key->value->type != OBJ_STRING) return REDISMODULE_ERR;
if (newlen > 512*1024*1024) return REDISMODULE_ERR;
/* Empty key and new len set to 0. Just return REDISMODULE_OK without
* doing anything. */
if (key->value == NULL && newlen == 0) return REDISMODULE_OK;
if (key->value == NULL) {
/* Empty key: create it with the new size. */
robj *o = createObject(OBJ_STRING,sdsnewlen(NULL, newlen));
genericSetKey(key->ctx->client,key->db,key->key,o,0,0);
key->value = o;
decrRefCount(o);
} else {
/* Unshare and resize. */
key->value = dbUnshareStringValue(key->db, key->key, key->value);
size_t curlen = sdslen(key->value->ptr);
if (newlen > curlen) {
key->value->ptr = sdsgrowzero(key->value->ptr,newlen);
} else if (newlen < curlen) {
sdsrange(key->value->ptr,0,newlen-1);
/* If the string is too wasteful, reallocate it. */
if (sdslen(key->value->ptr) < sdsavail(key->value->ptr))
key->value->ptr = sdsRemoveFreeSpace(key->value->ptr);
}
}
return REDISMODULE_OK;
}
/* --------------------------------------------------------------------------
* Key API for List type
* -------------------------------------------------------------------------- */
/* Push an element into a list, on head or tail depending on 'where' argument.
* If the key pointer is about an empty key opened for writing, the key
* is created. On error (key opened for read-only operations or of the wrong
* type) REDISMODULE_ERR is returned, otherwise REDISMODULE_OK is returned. */
int RM_ListPush(RedisModuleKey *key, int where, RedisModuleString *ele) {
if (!(key->mode & REDISMODULE_WRITE)) return REDISMODULE_ERR;
if (key->value && key->value->type != OBJ_LIST) return REDISMODULE_ERR;
if (key->value == NULL) moduleCreateEmptyKey(key,REDISMODULE_KEYTYPE_LIST);
listTypePush(key->value, ele,
(where == REDISMODULE_LIST_HEAD) ? QUICKLIST_HEAD : QUICKLIST_TAIL);
return REDISMODULE_OK;
}
/* Pop an element from the list, and returns it as a module string object
* that the user should be free with RM_FreeString() or by enabling
* automatic memory. 'where' specifies if the element should be popped from
* head or tail. The command returns NULL if:
* 1) The list is empty.
* 2) The key was not open for writing.
* 3) The key is not a list. */
RedisModuleString *RM_ListPop(RedisModuleKey *key, int where) {
if (!(key->mode & REDISMODULE_WRITE) ||
key->value == NULL ||
key->value->type != OBJ_LIST) return NULL;
robj *ele = listTypePop(key->value,
(where == REDISMODULE_LIST_HEAD) ? QUICKLIST_HEAD : QUICKLIST_TAIL);
robj *decoded = getDecodedObject(ele);
decrRefCount(ele);
moduleDelKeyIfEmpty(key);
autoMemoryAdd(key->ctx,REDISMODULE_AM_STRING,decoded);
return decoded;
}
/* --------------------------------------------------------------------------
* Key API for Sorted Set type
* -------------------------------------------------------------------------- */
/* Conversion from/to public flags of the Modules API and our private flags,
* so that we have everything decoupled. */
int RM_ZsetAddFlagsToCoreFlags(int flags) {
int retflags = 0;
if (flags & REDISMODULE_ZADD_XX) retflags |= ZADD_XX;
if (flags & REDISMODULE_ZADD_NX) retflags |= ZADD_NX;
if (flags & REDISMODULE_ZADD_GT) retflags |= ZADD_GT;
if (flags & REDISMODULE_ZADD_LT) retflags |= ZADD_LT;
return retflags;
}
/* See previous function comment. */
int RM_ZsetAddFlagsFromCoreFlags(int flags) {
int retflags = 0;
if (flags & ZADD_ADDED) retflags |= REDISMODULE_ZADD_ADDED;
if (flags & ZADD_UPDATED) retflags |= REDISMODULE_ZADD_UPDATED;
if (flags & ZADD_NOP) retflags |= REDISMODULE_ZADD_NOP;
return retflags;
}
/* Add a new element into a sorted set, with the specified 'score'.
* If the element already exists, the score is updated.
*
* A new sorted set is created at value if the key is an empty open key
* setup for writing.
*
* Additional flags can be passed to the function via a pointer, the flags
* are both used to receive input and to communicate state when the function
* returns. 'flagsptr' can be NULL if no special flags are used.
*
* The input flags are:
*
* REDISMODULE_ZADD_XX: Element must already exist. Do nothing otherwise.
* REDISMODULE_ZADD_NX: Element must not exist. Do nothing otherwise.
* REDISMODULE_ZADD_GT: If element exists, new score must be greater than the current score.
* Do nothing otherwise. Can optionally be combined with XX.
* REDISMODULE_ZADD_LT: If element exists, new score must be less than the current score.
* Do nothing otherwise. Can optionally be combined with XX.
*
* The output flags are:
*
* REDISMODULE_ZADD_ADDED: The new element was added to the sorted set.
* REDISMODULE_ZADD_UPDATED: The score of the element was updated.
* REDISMODULE_ZADD_NOP: No operation was performed because XX or NX flags.
*
* On success the function returns REDISMODULE_OK. On the following errors
* REDISMODULE_ERR is returned:
*
* * The key was not opened for writing.
* * The key is of the wrong type.
* * 'score' double value is not a number (NaN).
*/
int RM_ZsetAdd(RedisModuleKey *key, double score, RedisModuleString *ele, int *flagsptr) {
int flags = 0;
if (!(key->mode & REDISMODULE_WRITE)) return REDISMODULE_ERR;
if (key->value && key->value->type != OBJ_ZSET) return REDISMODULE_ERR;
if (key->value == NULL) moduleCreateEmptyKey(key,REDISMODULE_KEYTYPE_ZSET);
if (flagsptr) flags = RM_ZsetAddFlagsToCoreFlags(*flagsptr);
if (zsetAdd(key->value,score,ele->ptr,&flags,NULL) == 0) {
if (flagsptr) *flagsptr = 0;
return REDISMODULE_ERR;
}
if (flagsptr) *flagsptr = RM_ZsetAddFlagsFromCoreFlags(flags);
return REDISMODULE_OK;
}
/* This function works exactly like RM_ZsetAdd(), but instead of setting
* a new score, the score of the existing element is incremented, or if the
* element does not already exist, it is added assuming the old score was
* zero.
*
* The input and output flags, and the return value, have the same exact
* meaning, with the only difference that this function will return
* REDISMODULE_ERR even when 'score' is a valid double number, but adding it
* to the existing score results into a NaN (not a number) condition.
*
* This function has an additional field 'newscore', if not NULL is filled
* with the new score of the element after the increment, if no error
* is returned. */
int RM_ZsetIncrby(RedisModuleKey *key, double score, RedisModuleString *ele, int *flagsptr, double *newscore) {
int flags = 0;
if (!(key->mode & REDISMODULE_WRITE)) return REDISMODULE_ERR;
if (key->value && key->value->type != OBJ_ZSET) return REDISMODULE_ERR;
if (key->value == NULL) moduleCreateEmptyKey(key,REDISMODULE_KEYTYPE_ZSET);
if (flagsptr) flags = RM_ZsetAddFlagsToCoreFlags(*flagsptr);
flags |= ZADD_INCR;
if (zsetAdd(key->value,score,ele->ptr,&flags,newscore) == 0) {
if (flagsptr) *flagsptr = 0;
return REDISMODULE_ERR;
}
/* zsetAdd() may signal back that the resulting score is not a number. */
if (flagsptr && (*flagsptr & ZADD_NAN)) {
*flagsptr = 0;
return REDISMODULE_ERR;
}
if (flagsptr) *flagsptr = RM_ZsetAddFlagsFromCoreFlags(flags);
return REDISMODULE_OK;
}
/* Remove the specified element from the sorted set.
* The function returns REDISMODULE_OK on success, and REDISMODULE_ERR
* on one of the following conditions:
*
* * The key was not opened for writing.
* * The key is of the wrong type.
*
* The return value does NOT indicate the fact the element was really
* removed (since it existed) or not, just if the function was executed
* with success.
*
* In order to know if the element was removed, the additional argument
* 'deleted' must be passed, that populates the integer by reference
* setting it to 1 or 0 depending on the outcome of the operation.
* The 'deleted' argument can be NULL if the caller is not interested
* to know if the element was really removed.
*
* Empty keys will be handled correctly by doing nothing. */
int RM_ZsetRem(RedisModuleKey *key, RedisModuleString *ele, int *deleted) {
if (!(key->mode & REDISMODULE_WRITE)) return REDISMODULE_ERR;
if (key->value && key->value->type != OBJ_ZSET) return REDISMODULE_ERR;
if (key->value != NULL && zsetDel(key->value,ele->ptr)) {
if (deleted) *deleted = 1;
} else {
if (deleted) *deleted = 0;
}
return REDISMODULE_OK;
}
/* On success retrieve the double score associated at the sorted set element
* 'ele' and returns REDISMODULE_OK. Otherwise REDISMODULE_ERR is returned
* to signal one of the following conditions:
*
* * There is no such element 'ele' in the sorted set.
* * The key is not a sorted set.
* * The key is an open empty key.
*/
int RM_ZsetScore(RedisModuleKey *key, RedisModuleString *ele, double *score) {
if (key->value == NULL) return REDISMODULE_ERR;
if (key->value->type != OBJ_ZSET) return REDISMODULE_ERR;
if (zsetScore(key->value,ele->ptr,score) == C_ERR) return REDISMODULE_ERR;
return REDISMODULE_OK;
}
/* --------------------------------------------------------------------------
* Key API for Sorted Set iterator
* -------------------------------------------------------------------------- */
void zsetKeyReset(RedisModuleKey *key) {
key->ztype = REDISMODULE_ZSET_RANGE_NONE;
key->zcurrent = NULL;
key->zer = 1;
}
/* Stop a sorted set iteration. */
void RM_ZsetRangeStop(RedisModuleKey *key) {
/* Free resources if needed. */
if (key->ztype == REDISMODULE_ZSET_RANGE_LEX)
zslFreeLexRange(&key->zlrs);
/* Setup sensible values so that misused iteration API calls when an
* iterator is not active will result into something more sensible
* than crashing. */
zsetKeyReset(key);
}
/* Return the "End of range" flag value to signal the end of the iteration. */
int RM_ZsetRangeEndReached(RedisModuleKey *key) {
return key->zer;
}
/* Helper function for RM_ZsetFirstInScoreRange() and RM_ZsetLastInScoreRange().
* Setup the sorted set iteration according to the specified score range
* (see the functions calling it for more info). If 'first' is true the
* first element in the range is used as a starting point for the iterator
* otherwise the last. Return REDISMODULE_OK on success otherwise
* REDISMODULE_ERR. */
int zsetInitScoreRange(RedisModuleKey *key, double min, double max, int minex, int maxex, int first) {
if (!key->value || key->value->type != OBJ_ZSET) return REDISMODULE_ERR;
RM_ZsetRangeStop(key);
key->ztype = REDISMODULE_ZSET_RANGE_SCORE;
key->zer = 0;
/* Setup the range structure used by the sorted set core implementation
* in order to seek at the specified element. */
zrangespec *zrs = &key->zrs;
zrs->min = min;
zrs->max = max;
zrs->minex = minex;
zrs->maxex = maxex;
if (key->value->encoding == OBJ_ENCODING_ZIPLIST) {
key->zcurrent = first ? zzlFirstInRange(key->value->ptr,zrs) :
zzlLastInRange(key->value->ptr,zrs);
} else if (key->value->encoding == OBJ_ENCODING_SKIPLIST) {
zset *zs = key->value->ptr;
zskiplist *zsl = zs->zsl;
key->zcurrent = first ? zslFirstInRange(zsl,zrs) :
zslLastInRange(zsl,zrs);
} else {
serverPanic("Unsupported zset encoding");
}
if (key->zcurrent == NULL) key->zer = 1;
return REDISMODULE_OK;
}
/* Setup a sorted set iterator seeking the first element in the specified
* range. Returns REDISMODULE_OK if the iterator was correctly initialized
* otherwise REDISMODULE_ERR is returned in the following conditions:
*
* 1. The value stored at key is not a sorted set or the key is empty.
*
* The range is specified according to the two double values 'min' and 'max'.
* Both can be infinite using the following two macros:
*
* REDISMODULE_POSITIVE_INFINITE for positive infinite value
* REDISMODULE_NEGATIVE_INFINITE for negative infinite value
*
* 'minex' and 'maxex' parameters, if true, respectively setup a range
* where the min and max value are exclusive (not included) instead of
* inclusive. */
int RM_ZsetFirstInScoreRange(RedisModuleKey *key, double min, double max, int minex, int maxex) {
return zsetInitScoreRange(key,min,max,minex,maxex,1);
}
/* Exactly like RedisModule_ZsetFirstInScoreRange() but the last element of
* the range is selected for the start of the iteration instead. */
int RM_ZsetLastInScoreRange(RedisModuleKey *key, double min, double max, int minex, int maxex) {
return zsetInitScoreRange(key,min,max,minex,maxex,0);
}
/* Helper function for RM_ZsetFirstInLexRange() and RM_ZsetLastInLexRange().
* Setup the sorted set iteration according to the specified lexicographical
* range (see the functions calling it for more info). If 'first' is true the
* first element in the range is used as a starting point for the iterator
* otherwise the last. Return REDISMODULE_OK on success otherwise
* REDISMODULE_ERR.
*
* Note that this function takes 'min' and 'max' in the same form of the
* Redis ZRANGEBYLEX command. */
int zsetInitLexRange(RedisModuleKey *key, RedisModuleString *min, RedisModuleString *max, int first) {
if (!key->value || key->value->type != OBJ_ZSET) return REDISMODULE_ERR;
RM_ZsetRangeStop(key);
key->zer = 0;
/* Setup the range structure used by the sorted set core implementation
* in order to seek at the specified element. */
zlexrangespec *zlrs = &key->zlrs;
if (zslParseLexRange(min, max, zlrs) == C_ERR) return REDISMODULE_ERR;
/* Set the range type to lex only after successfully parsing the range,
* otherwise we don't want the zlexrangespec to be freed. */
key->ztype = REDISMODULE_ZSET_RANGE_LEX;
if (key->value->encoding == OBJ_ENCODING_ZIPLIST) {
key->zcurrent = first ? zzlFirstInLexRange(key->value->ptr,zlrs) :
zzlLastInLexRange(key->value->ptr,zlrs);
} else if (key->value->encoding == OBJ_ENCODING_SKIPLIST) {
zset *zs = key->value->ptr;
zskiplist *zsl = zs->zsl;
key->zcurrent = first ? zslFirstInLexRange(zsl,zlrs) :
zslLastInLexRange(zsl,zlrs);
} else {
serverPanic("Unsupported zset encoding");
}
if (key->zcurrent == NULL) key->zer = 1;
return REDISMODULE_OK;
}
/* Setup a sorted set iterator seeking the first element in the specified
* lexicographical range. Returns REDISMODULE_OK if the iterator was correctly
* initialized otherwise REDISMODULE_ERR is returned in the
* following conditions:
*
* 1. The value stored at key is not a sorted set or the key is empty.
* 2. The lexicographical range 'min' and 'max' format is invalid.
*
* 'min' and 'max' should be provided as two RedisModuleString objects
* in the same format as the parameters passed to the ZRANGEBYLEX command.
* The function does not take ownership of the objects, so they can be released
* ASAP after the iterator is setup. */
int RM_ZsetFirstInLexRange(RedisModuleKey *key, RedisModuleString *min, RedisModuleString *max) {
return zsetInitLexRange(key,min,max,1);
}
/* Exactly like RedisModule_ZsetFirstInLexRange() but the last element of
* the range is selected for the start of the iteration instead. */
int RM_ZsetLastInLexRange(RedisModuleKey *key, RedisModuleString *min, RedisModuleString *max) {
return zsetInitLexRange(key,min,max,0);
}
/* Return the current sorted set element of an active sorted set iterator
* or NULL if the range specified in the iterator does not include any
* element. */
RedisModuleString *RM_ZsetRangeCurrentElement(RedisModuleKey *key, double *score) {
RedisModuleString *str;
if (key->zcurrent == NULL) return NULL;
if (key->value->encoding == OBJ_ENCODING_ZIPLIST) {
unsigned char *eptr, *sptr;
eptr = key->zcurrent;
sds ele = ziplistGetObject(eptr);
if (score) {
sptr = ziplistNext(key->value->ptr,eptr);
*score = zzlGetScore(sptr);
}
str = createObject(OBJ_STRING,ele);
} else if (key->value->encoding == OBJ_ENCODING_SKIPLIST) {
zskiplistNode *ln = key->zcurrent;
if (score) *score = ln->score;
str = createStringObject(ln->ele,sdslen(ln->ele));
} else {
serverPanic("Unsupported zset encoding");
}
autoMemoryAdd(key->ctx,REDISMODULE_AM_STRING,str);
return str;
}
/* Go to the next element of the sorted set iterator. Returns 1 if there was
* a next element, 0 if we are already at the latest element or the range
* does not include any item at all. */
int RM_ZsetRangeNext(RedisModuleKey *key) {
if (!key->ztype || !key->zcurrent) return 0; /* No active iterator. */
if (key->value->encoding == OBJ_ENCODING_ZIPLIST) {
unsigned char *zl = key->value->ptr;
unsigned char *eptr = key->zcurrent;
unsigned char *next;
next = ziplistNext(zl,eptr); /* Skip element. */
if (next) next = ziplistNext(zl,next); /* Skip score. */
if (next == NULL) {
key->zer = 1;
return 0;
} else {
/* Are we still within the range? */
if (key->ztype == REDISMODULE_ZSET_RANGE_SCORE) {
/* Fetch the next element score for the
* range check. */
unsigned char *saved_next = next;
next = ziplistNext(zl,next); /* Skip next element. */
double score = zzlGetScore(next); /* Obtain the next score. */
if (!zslValueLteMax(score,&key->zrs)) {
key->zer = 1;
return 0;
}
next = saved_next;
} else if (key->ztype == REDISMODULE_ZSET_RANGE_LEX) {
if (!zzlLexValueLteMax(next,&key->zlrs)) {
key->zer = 1;
return 0;
}
}
key->zcurrent = next;
return 1;
}
} else if (key->value->encoding == OBJ_ENCODING_SKIPLIST) {
zskiplistNode *ln = key->zcurrent, *next = ln->level[0].forward;
if (next == NULL) {
key->zer = 1;
return 0;
} else {
/* Are we still within the range? */
if (key->ztype == REDISMODULE_ZSET_RANGE_SCORE &&
!zslValueLteMax(next->score,&key->zrs))
{
key->zer = 1;
return 0;
} else if (key->ztype == REDISMODULE_ZSET_RANGE_LEX) {
if (!zslLexValueLteMax(next->ele,&key->zlrs)) {
key->zer = 1;
return 0;
}
}
key->zcurrent = next;
return 1;
}
} else {
serverPanic("Unsupported zset encoding");
}
}
/* Go to the previous element of the sorted set iterator. Returns 1 if there was
* a previous element, 0 if we are already at the first element or the range
* does not include any item at all. */
int RM_ZsetRangePrev(RedisModuleKey *key) {
if (!key->ztype || !key->zcurrent) return 0; /* No active iterator. */
if (key->value->encoding == OBJ_ENCODING_ZIPLIST) {
unsigned char *zl = key->value->ptr;
unsigned char *eptr = key->zcurrent;
unsigned char *prev;
prev = ziplistPrev(zl,eptr); /* Go back to previous score. */
if (prev) prev = ziplistPrev(zl,prev); /* Back to previous ele. */
if (prev == NULL) {
key->zer = 1;
return 0;
} else {
/* Are we still within the range? */
if (key->ztype == REDISMODULE_ZSET_RANGE_SCORE) {
/* Fetch the previous element score for the
* range check. */
unsigned char *saved_prev = prev;
prev = ziplistNext(zl,prev); /* Skip element to get the score.*/
double score = zzlGetScore(prev); /* Obtain the prev score. */
if (!zslValueGteMin(score,&key->zrs)) {
key->zer = 1;
return 0;
}
prev = saved_prev;
} else if (key->ztype == REDISMODULE_ZSET_RANGE_LEX) {
if (!zzlLexValueGteMin(prev,&key->zlrs)) {
key->zer = 1;
return 0;
}
}
key->zcurrent = prev;
return 1;
}
} else if (key->value->encoding == OBJ_ENCODING_SKIPLIST) {
zskiplistNode *ln = key->zcurrent, *prev = ln->backward;
if (prev == NULL) {
key->zer = 1;
return 0;
} else {
/* Are we still within the range? */
if (key->ztype == REDISMODULE_ZSET_RANGE_SCORE &&
!zslValueGteMin(prev->score,&key->zrs))
{
key->zer = 1;
return 0;
} else if (key->ztype == REDISMODULE_ZSET_RANGE_LEX) {
if (!zslLexValueGteMin(prev->ele,&key->zlrs)) {
key->zer = 1;
return 0;
}
}
key->zcurrent = prev;
return 1;
}
} else {
serverPanic("Unsupported zset encoding");
}
}
/* --------------------------------------------------------------------------
* Key API for Hash type
* -------------------------------------------------------------------------- */
/* Set the field of the specified hash field to the specified value.
* If the key is an empty key open for writing, it is created with an empty
* hash value, in order to set the specified field.
*
* The function is variadic and the user must specify pairs of field
* names and values, both as RedisModuleString pointers (unless the
* CFIELD option is set, see later). At the end of the field/value-ptr pairs,
* NULL must be specified as last argument to signal the end of the arguments
* in the variadic function.
*
* Example to set the hash argv[1] to the value argv[2]:
*
* RedisModule_HashSet(key,REDISMODULE_HASH_NONE,argv[1],argv[2],NULL);
*
* The function can also be used in order to delete fields (if they exist)
* by setting them to the specified value of REDISMODULE_HASH_DELETE:
*
* RedisModule_HashSet(key,REDISMODULE_HASH_NONE,argv[1],
* REDISMODULE_HASH_DELETE,NULL);
*
* The behavior of the command changes with the specified flags, that can be
* set to REDISMODULE_HASH_NONE if no special behavior is needed.
*
* REDISMODULE_HASH_NX: The operation is performed only if the field was not
* already existing in the hash.
* REDISMODULE_HASH_XX: The operation is performed only if the field was
* already existing, so that a new value could be
* associated to an existing filed, but no new fields
* are created.
* REDISMODULE_HASH_CFIELDS: The field names passed are null terminated C
* strings instead of RedisModuleString objects.
*
* Unless NX is specified, the command overwrites the old field value with
* the new one.
*
* When using REDISMODULE_HASH_CFIELDS, field names are reported using
* normal C strings, so for example to delete the field "foo" the following
* code can be used:
*
* RedisModule_HashSet(key,REDISMODULE_HASH_CFIELDS,"foo",
* REDISMODULE_HASH_DELETE,NULL);
*
* Return value:
*
* The number of fields updated (that may be less than the number of fields
* specified because of the XX or NX options).
*
* In the following case the return value is always zero:
*
* * The key was not open for writing.
* * The key was associated with a non Hash value.
*/
int RM_HashSet(RedisModuleKey *key, int flags, ...) {
va_list ap;
if (!(key->mode & REDISMODULE_WRITE)) return 0;
if (key->value && key->value->type != OBJ_HASH) return 0;
if (key->value == NULL) moduleCreateEmptyKey(key,REDISMODULE_KEYTYPE_HASH);
int updated = 0;
va_start(ap, flags);
while(1) {
RedisModuleString *field, *value;
/* Get the field and value objects. */
if (flags & REDISMODULE_HASH_CFIELDS) {
char *cfield = va_arg(ap,char*);
if (cfield == NULL) break;
field = createRawStringObject(cfield,strlen(cfield));
} else {
field = va_arg(ap,RedisModuleString*);
if (field == NULL) break;
}
value = va_arg(ap,RedisModuleString*);
/* Handle XX and NX */
if (flags & (REDISMODULE_HASH_XX|REDISMODULE_HASH_NX)) {
int exists = hashTypeExists(key->value, field->ptr);
if (((flags & REDISMODULE_HASH_XX) && !exists) ||
((flags & REDISMODULE_HASH_NX) && exists))
{
if (flags & REDISMODULE_HASH_CFIELDS) decrRefCount(field);
continue;
}
}
/* Handle deletion if value is REDISMODULE_HASH_DELETE. */
if (value == REDISMODULE_HASH_DELETE) {
updated += hashTypeDelete(key->value, field->ptr);
if (flags & REDISMODULE_HASH_CFIELDS) decrRefCount(field);
continue;
}
int low_flags = HASH_SET_COPY;
/* If CFIELDS is active, we can pass the ownership of the
* SDS object to the low level function that sets the field
* to avoid a useless copy. */
if (flags & REDISMODULE_HASH_CFIELDS)
low_flags |= HASH_SET_TAKE_FIELD;
robj *argv[2] = {field,value};
hashTypeTryConversion(key->value,argv,0,1);
updated += hashTypeSet(key->value, field->ptr, value->ptr, low_flags);
/* If CFIELDS is active, SDS string ownership is now of hashTypeSet(),
* however we still have to release the 'field' object shell. */
if (flags & REDISMODULE_HASH_CFIELDS) {
field->ptr = NULL; /* Prevent the SDS string from being freed. */
decrRefCount(field);
}
}
va_end(ap);
moduleDelKeyIfEmpty(key);
return updated;
}
/* Get fields from an hash value. This function is called using a variable
* number of arguments, alternating a field name (as a RedisModuleString
* pointer) with a pointer to a RedisModuleString pointer, that is set to the
* value of the field if the field exists, or NULL if the field does not exist.
* At the end of the field/value-ptr pairs, NULL must be specified as last
* argument to signal the end of the arguments in the variadic function.
*
* This is an example usage:
*
* RedisModuleString *first, *second;
* RedisModule_HashGet(mykey,REDISMODULE_HASH_NONE,argv[1],&first,
* argv[2],&second,NULL);
*
* As with RedisModule_HashSet() the behavior of the command can be specified
* passing flags different than REDISMODULE_HASH_NONE:
*
* REDISMODULE_HASH_CFIELDS: field names as null terminated C strings.
*
* REDISMODULE_HASH_EXISTS: instead of setting the value of the field
* expecting a RedisModuleString pointer to pointer, the function just
* reports if the field exists or not and expects an integer pointer
* as the second element of each pair.
*
* Example of REDISMODULE_HASH_CFIELDS:
*
* RedisModuleString *username, *hashedpass;
* RedisModule_HashGet(mykey,REDISMODULE_HASH_CFIELDS,"username",&username,"hp",&hashedpass, NULL);
*
* Example of REDISMODULE_HASH_EXISTS:
*
* int exists;
* RedisModule_HashGet(mykey,REDISMODULE_HASH_EXISTS,argv[1],&exists,NULL);
*
* The function returns REDISMODULE_OK on success and REDISMODULE_ERR if
* the key is not an hash value.
*
* Memory management:
*
* The returned RedisModuleString objects should be released with
* RedisModule_FreeString(), or by enabling automatic memory management.
*/
int RM_HashGet(RedisModuleKey *key, int flags, ...) {
va_list ap;
if (key->value && key->value->type != OBJ_HASH) return REDISMODULE_ERR;
va_start(ap, flags);
while(1) {
RedisModuleString *field, **valueptr;
int *existsptr;
/* Get the field object and the value pointer to pointer. */
if (flags & REDISMODULE_HASH_CFIELDS) {
char *cfield = va_arg(ap,char*);
if (cfield == NULL) break;
field = createRawStringObject(cfield,strlen(cfield));
} else {
field = va_arg(ap,RedisModuleString*);
if (field == NULL) break;
}
/* Query the hash for existence or value object. */
if (flags & REDISMODULE_HASH_EXISTS) {
existsptr = va_arg(ap,int*);
if (key->value)
*existsptr = hashTypeExists(key->value,field->ptr);
else
*existsptr = 0;
} else {
valueptr = va_arg(ap,RedisModuleString**);
if (key->value) {
*valueptr = hashTypeGetValueObject(key->value,field->ptr);
if (*valueptr) {
robj *decoded = getDecodedObject(*valueptr);
decrRefCount(*valueptr);
*valueptr = decoded;
}
if (*valueptr)
autoMemoryAdd(key->ctx,REDISMODULE_AM_STRING,*valueptr);
} else {
*valueptr = NULL;
}
}
/* Cleanup */
if (flags & REDISMODULE_HASH_CFIELDS) decrRefCount(field);
}
va_end(ap);
return REDISMODULE_OK;
}
/* --------------------------------------------------------------------------
* Redis <-> Modules generic Call() API
* -------------------------------------------------------------------------- */
/* Create a new RedisModuleCallReply object. The processing of the reply
* is lazy, the object is just populated with the raw protocol and later
* is processed as needed. Initially we just make sure to set the right
* reply type, which is extremely cheap to do. */
RedisModuleCallReply *moduleCreateCallReplyFromProto(RedisModuleCtx *ctx, sds proto) {
RedisModuleCallReply *reply = zmalloc(sizeof(*reply));
reply->ctx = ctx;
reply->proto = proto;
reply->protolen = sdslen(proto);
reply->flags = REDISMODULE_REPLYFLAG_TOPARSE; /* Lazy parsing. */
switch(proto[0]) {
case '$':
case '+': reply->type = REDISMODULE_REPLY_STRING; break;
case '-': reply->type = REDISMODULE_REPLY_ERROR; break;
case ':': reply->type = REDISMODULE_REPLY_INTEGER; break;
case '*': reply->type = REDISMODULE_REPLY_ARRAY; break;
default: reply->type = REDISMODULE_REPLY_UNKNOWN; break;
}
if ((proto[0] == '*' || proto[0] == '$') && proto[1] == '-')
reply->type = REDISMODULE_REPLY_NULL;
return reply;
}
void moduleParseCallReply_Int(RedisModuleCallReply *reply);
void moduleParseCallReply_BulkString(RedisModuleCallReply *reply);
void moduleParseCallReply_SimpleString(RedisModuleCallReply *reply);
void moduleParseCallReply_Array(RedisModuleCallReply *reply);
/* Do nothing if REDISMODULE_REPLYFLAG_TOPARSE is false, otherwise
* use the protocol of the reply in reply->proto in order to fill the
* reply with parsed data according to the reply type. */
void moduleParseCallReply(RedisModuleCallReply *reply) {
if (!(reply->flags & REDISMODULE_REPLYFLAG_TOPARSE)) return;
reply->flags &= ~REDISMODULE_REPLYFLAG_TOPARSE;
switch(reply->proto[0]) {
case ':': moduleParseCallReply_Int(reply); break;
case '$': moduleParseCallReply_BulkString(reply); break;
case '-': /* handled by next item. */
case '+': moduleParseCallReply_SimpleString(reply); break;
case '*': moduleParseCallReply_Array(reply); break;
}
}
void moduleParseCallReply_Int(RedisModuleCallReply *reply) {
char *proto = reply->proto;
char *p = strchr(proto+1,'\r');
string2ll(proto+1,p-proto-1,&reply->val.ll);
reply->protolen = p-proto+2;
reply->type = REDISMODULE_REPLY_INTEGER;
}
void moduleParseCallReply_BulkString(RedisModuleCallReply *reply) {
char *proto = reply->proto;
char *p = strchr(proto+1,'\r');
long long bulklen;
string2ll(proto+1,p-proto-1,&bulklen);
if (bulklen == -1) {
reply->protolen = p-proto+2;
reply->type = REDISMODULE_REPLY_NULL;
} else {
reply->val.str = p+2;
reply->len = bulklen;
reply->protolen = p-proto+2+bulklen+2;
reply->type = REDISMODULE_REPLY_STRING;
}
}
void moduleParseCallReply_SimpleString(RedisModuleCallReply *reply) {
char *proto = reply->proto;
char *p = strchr(proto+1,'\r');
reply->val.str = proto+1;
reply->len = p-proto-1;
reply->protolen = p-proto+2;
reply->type = proto[0] == '+' ? REDISMODULE_REPLY_STRING :
REDISMODULE_REPLY_ERROR;
}
void moduleParseCallReply_Array(RedisModuleCallReply *reply) {
char *proto = reply->proto;
char *p = strchr(proto+1,'\r');
long long arraylen, j;
string2ll(proto+1,p-proto-1,&arraylen);
p += 2;
if (arraylen == -1) {
reply->protolen = p-proto;
reply->type = REDISMODULE_REPLY_NULL;
return;
}
reply->val.array = zmalloc(sizeof(RedisModuleCallReply)*arraylen);
reply->len = arraylen;
for (j = 0; j < arraylen; j++) {
RedisModuleCallReply *ele = reply->val.array+j;
ele->flags = REDISMODULE_REPLYFLAG_NESTED |
REDISMODULE_REPLYFLAG_TOPARSE;
ele->proto = p;
ele->ctx = reply->ctx;
moduleParseCallReply(ele);
p += ele->protolen;
}
reply->protolen = p-proto;
reply->type = REDISMODULE_REPLY_ARRAY;
}
/* Free a Call reply and all the nested replies it contains if it's an
* array. */
void RM_FreeCallReply_Rec(RedisModuleCallReply *reply, int freenested){
/* Don't free nested replies by default: the user must always free the
* toplevel reply. However be gentle and don't crash if the module
* misuses the API. */
if (!freenested && reply->flags & REDISMODULE_REPLYFLAG_NESTED) return;
if (!(reply->flags & REDISMODULE_REPLYFLAG_TOPARSE)) {
if (reply->type == REDISMODULE_REPLY_ARRAY) {
size_t j;
for (j = 0; j < reply->len; j++)
RM_FreeCallReply_Rec(reply->val.array+j,1);
zfree(reply->val.array);
}
}
/* For nested replies, we don't free reply->proto (which if not NULL
* references the parent reply->proto buffer), nor the structure
* itself which is allocated as an array of structures, and is freed
* when the array value is released. */
if (!(reply->flags & REDISMODULE_REPLYFLAG_NESTED)) {
if (reply->proto) sdsfree(reply->proto);
zfree(reply);
}
}
/* Wrapper for the recursive free reply function. This is needed in order
* to have the first level function to return on nested replies, but only
* if called by the module API. */
void RM_FreeCallReply(RedisModuleCallReply *reply) {
RedisModuleCtx *ctx = reply->ctx;
RM_FreeCallReply_Rec(reply,0);
autoMemoryFreed(ctx,REDISMODULE_AM_REPLY,reply);
}
/* Return the reply type. */
int RM_CallReplyType(RedisModuleCallReply *reply) {
if (!reply) return REDISMODULE_REPLY_UNKNOWN;
return reply->type;
}
/* Return the reply type length, where applicable. */
size_t RM_CallReplyLength(RedisModuleCallReply *reply) {
moduleParseCallReply(reply);
switch(reply->type) {
case REDISMODULE_REPLY_STRING:
case REDISMODULE_REPLY_ERROR:
case REDISMODULE_REPLY_ARRAY:
return reply->len;
default:
return 0;
}
}
/* Return the 'idx'-th nested call reply element of an array reply, or NULL
* if the reply type is wrong or the index is out of range. */
RedisModuleCallReply *RM_CallReplyArrayElement(RedisModuleCallReply *reply, size_t idx) {
moduleParseCallReply(reply);
if (reply->type != REDISMODULE_REPLY_ARRAY) return NULL;
if (idx >= reply->len) return NULL;
return reply->val.array+idx;
}
/* Return the long long of an integer reply. */
long long RM_CallReplyInteger(RedisModuleCallReply *reply) {
moduleParseCallReply(reply);
if (reply->type != REDISMODULE_REPLY_INTEGER) return LLONG_MIN;
return reply->val.ll;
}
/* Return the pointer and length of a string or error reply. */
const char *RM_CallReplyStringPtr(RedisModuleCallReply *reply, size_t *len) {
moduleParseCallReply(reply);
if (reply->type != REDISMODULE_REPLY_STRING &&
reply->type != REDISMODULE_REPLY_ERROR) return NULL;
if (len) *len = reply->len;
return reply->val.str;
}
/* Return a new string object from a call reply of type string, error or
* integer. Otherwise (wrong reply type) return NULL. */
RedisModuleString *RM_CreateStringFromCallReply(RedisModuleCallReply *reply) {
moduleParseCallReply(reply);
switch(reply->type) {
case REDISMODULE_REPLY_STRING:
case REDISMODULE_REPLY_ERROR:
return RM_CreateString(reply->ctx,reply->val.str,reply->len);
case REDISMODULE_REPLY_INTEGER: {
char buf[64];
int len = ll2string(buf,sizeof(buf),reply->val.ll);
return RM_CreateString(reply->ctx,buf,len);
}
default: return NULL;
}
}
/* Returns an array of robj pointers, and populates *argc with the number
* of items, by parsing the format specifier "fmt" as described for
* the RM_Call(), RM_Replicate() and other module APIs.
*
* The integer pointed by 'flags' is populated with flags according
* to special modifiers in "fmt". For now only one exists:
*
* "!" -> REDISMODULE_ARGV_REPLICATE
* "A" -> REDISMODULE_ARGV_NO_AOF
* "R" -> REDISMODULE_ARGV_NO_REPLICAS
*
* On error (format specifier error) NULL is returned and nothing is
* allocated. On success the argument vector is returned. */
robj **moduleCreateArgvFromUserFormat(const char *cmdname, const char *fmt, int *argcp, int *flags, va_list ap) {
int argc = 0, argv_size, j;
robj **argv = NULL;
/* As a first guess to avoid useless reallocations, size argv to
* hold one argument for each char specifier in 'fmt'. */
argv_size = strlen(fmt)+1; /* +1 because of the command name. */
argv = zrealloc(argv,sizeof(robj*)*argv_size);
/* Build the arguments vector based on the format specifier. */
argv[0] = createStringObject(cmdname,strlen(cmdname));
argc++;
/* Create the client and dispatch the command. */
const char *p = fmt;
while(*p) {
if (*p == 'c') {
char *cstr = va_arg(ap,char*);
argv[argc++] = createStringObject(cstr,strlen(cstr));
} else if (*p == 's') {
robj *obj = va_arg(ap,void*);
if (obj->refcount == OBJ_STATIC_REFCOUNT)
obj = createStringObject(obj->ptr,sdslen(obj->ptr));
else
incrRefCount(obj);
argv[argc++] = obj;
} else if (*p == 'b') {
char *buf = va_arg(ap,char*);
size_t len = va_arg(ap,size_t);
argv[argc++] = createStringObject(buf,len);
} else if (*p == 'l') {
long long ll = va_arg(ap,long long);
argv[argc++] = createObject(OBJ_STRING,sdsfromlonglong(ll));
} else if (*p == 'v') {
/* A vector of strings */
robj **v = va_arg(ap, void*);
size_t vlen = va_arg(ap, size_t);
/* We need to grow argv to hold the vector's elements.
* We resize by vector_len-1 elements, because we held
* one element in argv for the vector already */
argv_size += vlen-1;
argv = zrealloc(argv,sizeof(robj*)*argv_size);
size_t i = 0;
for (i = 0; i < vlen; i++) {
incrRefCount(v[i]);
argv[argc++] = v[i];
}
} else if (*p == '!') {
if (flags) (*flags) |= REDISMODULE_ARGV_REPLICATE;
} else if (*p == 'A') {
if (flags) (*flags) |= REDISMODULE_ARGV_NO_AOF;
} else if (*p == 'R') {
if (flags) (*flags) |= REDISMODULE_ARGV_NO_REPLICAS;
} else {
goto fmterr;
}
p++;
}
*argcp = argc;
return argv;
fmterr:
for (j = 0; j < argc; j++)
decrRefCount(argv[j]);
zfree(argv);
return NULL;
}
/* Exported API to call any Redis command from modules.
*
* * **cmdname**: The Redis command to call.
* * **fmt**: A format specifier string for the command's arguments. Each
* of the arguments should be specified by a valid type specification:
* b The argument is a buffer and is immediately followed by another
* argument that is the buffer's length.
* c The argument is a pointer to a plain C string (null-terminated).
* l The argument is long long integer.
* s The argument is a RedisModuleString.
* v The argument(s) is a vector of RedisModuleString.
*
* The format specifier can also include modifiers:
* ! Sends the Redis command and its arguments to replicas and AOF.
* A Suppress AOF propagation, send only to replicas (requires `!`).
* R Suppress replicas propagation, send only to AOF (requires `!`).
* * **...**: The actual arguments to the Redis command.
*
* On success a RedisModuleCallReply object is returned, otherwise
* NULL is returned and errno is set to the following values:
*
* EBADF: wrong format specifier.
* EINVAL: wrong command arity.
* ENOENT: command does not exist.
* EPERM: operation in Cluster instance with key in non local slot.
* EROFS: operation in Cluster instance when a write command is sent
* in a readonly state.
* ENETDOWN: operation in Cluster instance when cluster is down.
*
* Example code fragment:
*
* reply = RedisModule_Call(ctx,"INCRBY","sc",argv[1],"10");
* if (RedisModule_CallReplyType(reply) == REDISMODULE_REPLY_INTEGER) {
* long long myval = RedisModule_CallReplyInteger(reply);
* // Do something with myval.
* }
*
* This API is documented here: https://redis.io/topics/modules-intro
*/
RedisModuleCallReply *RM_Call(RedisModuleCtx *ctx, const char *cmdname, const char *fmt, ...) {
struct redisCommand *cmd;
client *c = NULL;
robj **argv = NULL;
int argc = 0, flags = 0;
va_list ap;
RedisModuleCallReply *reply = NULL;
int replicate = 0; /* Replicate this command? */
/* Create the client and dispatch the command. */
va_start(ap, fmt);
c = createClient(NULL);
c->user = NULL; /* Root user. */
argv = moduleCreateArgvFromUserFormat(cmdname,fmt,&argc,&flags,ap);
replicate = flags & REDISMODULE_ARGV_REPLICATE;
va_end(ap);
/* Setup our fake client for command execution. */
c->flags |= CLIENT_MODULE;
c->db = ctx->client->db;
c->argv = argv;
c->argc = argc;
if (ctx->module) ctx->module->in_call++;
/* We handle the above format error only when the client is setup so that
* we can free it normally. */
if (argv == NULL) {
errno = EBADF;
goto cleanup;
}
/* Call command filters */
moduleCallCommandFilters(c);
/* Lookup command now, after filters had a chance to make modifications
* if necessary.
*/
cmd = lookupCommand(c->argv[0]->ptr);
if (!cmd) {
errno = ENOENT;
goto cleanup;
}
c->cmd = c->lastcmd = cmd;
/* Basic arity checks. */
if ((cmd->arity > 0 && cmd->arity != argc) || (argc < -cmd->arity)) {
errno = EINVAL;
goto cleanup;
}
/* If this is a Redis Cluster node, we need to make sure the module is not
* trying to access non-local keys, with the exception of commands
* received from our master. */
if (server.cluster_enabled && !(ctx->client->flags & CLIENT_MASTER)) {
int error_code;
/* Duplicate relevant flags in the module client. */
c->flags &= ~(CLIENT_READONLY|CLIENT_ASKING);
c->flags |= ctx->client->flags & (CLIENT_READONLY|CLIENT_ASKING);
if (getNodeByQuery(c,c->cmd,c->argv,c->argc,NULL,&error_code) !=
server.cluster->myself)
{
if (error_code == CLUSTER_REDIR_DOWN_RO_STATE) {
errno = EROFS;
} else if (error_code == CLUSTER_REDIR_DOWN_STATE) {
errno = ENETDOWN;
} else {
errno = EPERM;
}
goto cleanup;
}
}
/* If we are using single commands replication, we need to wrap what
* we propagate into a MULTI/EXEC block, so that it will be atomic like
* a Lua script in the context of AOF and slaves. */
if (replicate) moduleReplicateMultiIfNeeded(ctx);
/* Run the command */
int call_flags = CMD_CALL_SLOWLOG | CMD_CALL_STATS | CMD_CALL_NOWRAP;
if (replicate) {
if (!(flags & REDISMODULE_ARGV_NO_AOF))
call_flags |= CMD_CALL_PROPAGATE_AOF;
if (!(flags & REDISMODULE_ARGV_NO_REPLICAS))
call_flags |= CMD_CALL_PROPAGATE_REPL;
}
call(c,call_flags);
/* Convert the result of the Redis command into a module reply. */
sds proto = sdsnewlen(c->buf,c->bufpos);
c->bufpos = 0;
while(listLength(c->reply)) {
clientReplyBlock *o = listNodeValue(listFirst(c->reply));
proto = sdscatlen(proto,o->buf,o->used);
listDelNode(c->reply,listFirst(c->reply));
}
reply = moduleCreateCallReplyFromProto(ctx,proto);
autoMemoryAdd(ctx,REDISMODULE_AM_REPLY,reply);
cleanup:
if (ctx->module) ctx->module->in_call--;
freeClient(c);
return reply;
}
/* Return a pointer, and a length, to the protocol returned by the command
* that returned the reply object. */
const char *RM_CallReplyProto(RedisModuleCallReply *reply, size_t *len) {
if (reply->proto) *len = sdslen(reply->proto);
return reply->proto;
}
/* --------------------------------------------------------------------------
* Modules data types
*
* When String DMA or using existing data structures is not enough, it is
* possible to create new data types from scratch and export them to
* Redis. The module must provide a set of callbacks for handling the
* new values exported (for example in order to provide RDB saving/loading,
* AOF rewrite, and so forth). In this section we define this API.
* -------------------------------------------------------------------------- */
/* Turn a 9 chars name in the specified charset and a 10 bit encver into
* a single 64 bit unsigned integer that represents this exact module name
* and version. This final number is called a "type ID" and is used when
* writing module exported values to RDB files, in order to re-associate the
* value to the right module to load them during RDB loading.
*
* If the string is not of the right length or the charset is wrong, or
* if encver is outside the unsigned 10 bit integer range, 0 is returned,
* otherwise the function returns the right type ID.
*
* The resulting 64 bit integer is composed as follows:
*
* (high order bits) 6|6|6|6|6|6|6|6|6|10 (low order bits)
*
* The first 6 bits value is the first character, name[0], while the last
* 6 bits value, immediately before the 10 bits integer, is name[8].
* The last 10 bits are the encoding version.
*
* Note that a name and encver combo of "AAAAAAAAA" and 0, will produce
* zero as return value, that is the same we use to signal errors, thus
* this combination is invalid, and also useless since type names should
* try to be vary to avoid collisions. */
const char *ModuleTypeNameCharSet =
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
"0123456789-_";
uint64_t moduleTypeEncodeId(const char *name, int encver) {
/* We use 64 symbols so that we can map each character into 6 bits
* of the final output. */
const char *cset = ModuleTypeNameCharSet;
if (strlen(name) != 9) return 0;
if (encver < 0 || encver > 1023) return 0;
uint64_t id = 0;
for (int j = 0; j < 9; j++) {
char *p = strchr(cset,name[j]);
if (!p) return 0;
unsigned long pos = p-cset;
id = (id << 6) | pos;
}
id = (id << 10) | encver;
return id;
}
/* Search, in the list of exported data types of all the modules registered,
* a type with the same name as the one given. Returns the moduleType
* structure pointer if such a module is found, or NULL otherwise. */
moduleType *moduleTypeLookupModuleByName(const char *name) {
dictIterator *di = dictGetIterator(modules);
dictEntry *de;
while ((de = dictNext(di)) != NULL) {
struct RedisModule *module = dictGetVal(de);
listIter li;
listNode *ln;
listRewind(module->types,&li);
while((ln = listNext(&li))) {
moduleType *mt = ln->value;
if (memcmp(name,mt->name,sizeof(mt->name)) == 0) {
dictReleaseIterator(di);
return mt;
}
}
}
dictReleaseIterator(di);
return NULL;
}
/* Lookup a module by ID, with caching. This function is used during RDB
* loading. Modules exporting data types should never be able to unload, so
* our cache does not need to expire. */
#define MODULE_LOOKUP_CACHE_SIZE 3
moduleType *moduleTypeLookupModuleByID(uint64_t id) {
static struct {
uint64_t id;
moduleType *mt;
} cache[MODULE_LOOKUP_CACHE_SIZE];
/* Search in cache to start. */
int j;
for (j = 0; j < MODULE_LOOKUP_CACHE_SIZE && cache[j].mt != NULL; j++)
if (cache[j].id == id) return cache[j].mt;
/* Slow module by module lookup. */
moduleType *mt = NULL;
dictIterator *di = dictGetIterator(modules);
dictEntry *de;
while ((de = dictNext(di)) != NULL && mt == NULL) {
struct RedisModule *module = dictGetVal(de);
listIter li;
listNode *ln;
listRewind(module->types,&li);
while((ln = listNext(&li))) {
moduleType *this_mt = ln->value;
/* Compare only the 54 bit module identifier and not the
* encoding version. */
if (this_mt->id >> 10 == id >> 10) {
mt = this_mt;
break;
}
}
}
dictReleaseIterator(di);
/* Add to cache if possible. */
if (mt && j < MODULE_LOOKUP_CACHE_SIZE) {
cache[j].id = id;
cache[j].mt = mt;
}
return mt;
}
/* Turn an (unresolved) module ID into a type name, to show the user an
* error when RDB files contain module data we can't load.
* The buffer pointed by 'name' must be 10 bytes at least. The function will
* fill it with a null terminated module name. */
void moduleTypeNameByID(char *name, uint64_t moduleid) {
const char *cset = ModuleTypeNameCharSet;
name[9] = '\0';
char *p = name+8;
moduleid >>= 10;
for (int j = 0; j < 9; j++) {
*p-- = cset[moduleid & 63];
moduleid >>= 6;
}
}
/* Register a new data type exported by the module. The parameters are the
* following. Please for in depth documentation check the modules API
* documentation, especially https://redis.io/topics/modules-native-types.
*
* * **name**: A 9 characters data type name that MUST be unique in the Redis
* Modules ecosystem. Be creative... and there will be no collisions. Use
* the charset A-Z a-z 9-0, plus the two "-_" characters. A good
* idea is to use, for example `<typename>-<vendor>`. For example
* "tree-AntZ" may mean "Tree data structure by @antirez". To use both
* lower case and upper case letters helps in order to prevent collisions.
* * **encver**: Encoding version, which is, the version of the serialization
* that a module used in order to persist data. As long as the "name"
* matches, the RDB loading will be dispatched to the type callbacks
* whatever 'encver' is used, however the module can understand if
* the encoding it must load are of an older version of the module.
* For example the module "tree-AntZ" initially used encver=0. Later
* after an upgrade, it started to serialize data in a different format
* and to register the type with encver=1. However this module may
* still load old data produced by an older version if the rdb_load
* callback is able to check the encver value and act accordingly.
* The encver must be a positive value between 0 and 1023.
* * **typemethods_ptr** is a pointer to a RedisModuleTypeMethods structure
* that should be populated with the methods callbacks and structure
* version, like in the following example:
*
* RedisModuleTypeMethods tm = {
* .version = REDISMODULE_TYPE_METHOD_VERSION,
* .rdb_load = myType_RDBLoadCallBack,
* .rdb_save = myType_RDBSaveCallBack,
* .aof_rewrite = myType_AOFRewriteCallBack,
* .free = myType_FreeCallBack,
*
* // Optional fields
* .digest = myType_DigestCallBack,
* .mem_usage = myType_MemUsageCallBack,
* .aux_load = myType_AuxRDBLoadCallBack,
* .aux_save = myType_AuxRDBSaveCallBack,
* }
*
* * **rdb_load**: A callback function pointer that loads data from RDB files.
* * **rdb_save**: A callback function pointer that saves data to RDB files.
* * **aof_rewrite**: A callback function pointer that rewrites data as commands.
* * **digest**: A callback function pointer that is used for `DEBUG DIGEST`.
* * **free**: A callback function pointer that can free a type value.
* * **aux_save**: A callback function pointer that saves out of keyspace data to RDB files.
* 'when' argument is either REDISMODULE_AUX_BEFORE_RDB or REDISMODULE_AUX_AFTER_RDB.
* * **aux_load**: A callback function pointer that loads out of keyspace data from RDB files.
* Similar to aux_save, returns REDISMODULE_OK on success, and ERR otherwise.
*
* The **digest** and **mem_usage** methods should currently be omitted since
* they are not yet implemented inside the Redis modules core.
*
* Note: the module name "AAAAAAAAA" is reserved and produces an error, it
* happens to be pretty lame as well.
*
* If there is already a module registering a type with the same name,
* and if the module name or encver is invalid, NULL is returned.
* Otherwise the new type is registered into Redis, and a reference of
* type RedisModuleType is returned: the caller of the function should store
* this reference into a global variable to make future use of it in the
* modules type API, since a single module may register multiple types.
* Example code fragment:
*
* static RedisModuleType *BalancedTreeType;
*
* int RedisModule_OnLoad(RedisModuleCtx *ctx) {
* // some code here ...
* BalancedTreeType = RM_CreateDataType(...);
* }
*/
moduleType *RM_CreateDataType(RedisModuleCtx *ctx, const char *name, int encver, void *typemethods_ptr) {
uint64_t id = moduleTypeEncodeId(name,encver);
if (id == 0) return NULL;
if (moduleTypeLookupModuleByName(name) != NULL) return NULL;
long typemethods_version = ((long*)typemethods_ptr)[0];
if (typemethods_version == 0) return NULL;
struct typemethods {
uint64_t version;
moduleTypeLoadFunc rdb_load;
moduleTypeSaveFunc rdb_save;
moduleTypeRewriteFunc aof_rewrite;
moduleTypeMemUsageFunc mem_usage;
moduleTypeDigestFunc digest;
moduleTypeFreeFunc free;
struct {
moduleTypeAuxLoadFunc aux_load;
moduleTypeAuxSaveFunc aux_save;
int aux_save_triggers;
} v2;
} *tms = (struct typemethods*) typemethods_ptr;
moduleType *mt = zcalloc(sizeof(*mt));
mt->id = id;
mt->module = ctx->module;
mt->rdb_load = tms->rdb_load;
mt->rdb_save = tms->rdb_save;
mt->aof_rewrite = tms->aof_rewrite;
mt->mem_usage = tms->mem_usage;
mt->digest = tms->digest;
mt->free = tms->free;
if (tms->version >= 2) {
mt->aux_load = tms->v2.aux_load;
mt->aux_save = tms->v2.aux_save;
mt->aux_save_triggers = tms->v2.aux_save_triggers;
}
memcpy(mt->name,name,sizeof(mt->name));
listAddNodeTail(ctx->module->types,mt);
return mt;
}
/* If the key is open for writing, set the specified module type object
* as the value of the key, deleting the old value if any.
* On success REDISMODULE_OK is returned. If the key is not open for
* writing or there is an active iterator, REDISMODULE_ERR is returned. */
int RM_ModuleTypeSetValue(RedisModuleKey *key, moduleType *mt, void *value) {
if (!(key->mode & REDISMODULE_WRITE) || key->iter) return REDISMODULE_ERR;
RM_DeleteKey(key);
robj *o = createModuleObject(mt,value);
genericSetKey(key->ctx->client,key->db,key->key,o,0,0);
decrRefCount(o);
key->value = o;
return REDISMODULE_OK;
}
/* Assuming RedisModule_KeyType() returned REDISMODULE_KEYTYPE_MODULE on
* the key, returns the module type pointer of the value stored at key.
*
* If the key is NULL, is not associated with a module type, or is empty,
* then NULL is returned instead. */
moduleType *RM_ModuleTypeGetType(RedisModuleKey *key) {
if (key == NULL ||
key->value == NULL ||
RM_KeyType(key) != REDISMODULE_KEYTYPE_MODULE) return NULL;
moduleValue *mv = key->value->ptr;
return mv->type;
}
/* Assuming RedisModule_KeyType() returned REDISMODULE_KEYTYPE_MODULE on
* the key, returns the module type low-level value stored at key, as
* it was set by the user via RedisModule_ModuleTypeSetValue().
*
* If the key is NULL, is not associated with a module type, or is empty,
* then NULL is returned instead. */
void *RM_ModuleTypeGetValue(RedisModuleKey *key) {
if (key == NULL ||
key->value == NULL ||
RM_KeyType(key) != REDISMODULE_KEYTYPE_MODULE) return NULL;
moduleValue *mv = key->value->ptr;
return mv->value;
}
/* --------------------------------------------------------------------------
* RDB loading and saving functions
* -------------------------------------------------------------------------- */
/* Called when there is a load error in the context of a module. On some
* modules this cannot be recovered, but if the module declared capability
* to handle errors, we'll raise a flag rather than exiting. */
void moduleRDBLoadError(RedisModuleIO *io) {
if (io->type->module->options & REDISMODULE_OPTIONS_HANDLE_IO_ERRORS) {
io->error = 1;
return;
}
serverPanic(
"Error loading data from RDB (short read or EOF). "
"Read performed by module '%s' about type '%s' "
"after reading '%llu' bytes of a value "
"for key named: '%s'.",
io->type->module->name,
io->type->name,
(unsigned long long)io->bytes,
io->key? (char*)io->key->ptr: "(null)");
}
/* Returns 0 if there's at least one registered data type that did not declare
* REDISMODULE_OPTIONS_HANDLE_IO_ERRORS, in which case diskless loading should
* be avoided since it could cause data loss. */
int moduleAllDatatypesHandleErrors() {
dictIterator *di = dictGetIterator(modules);
dictEntry *de;
while ((de = dictNext(di)) != NULL) {
struct RedisModule *module = dictGetVal(de);
if (listLength(module->types) &&
!(module->options & REDISMODULE_OPTIONS_HANDLE_IO_ERRORS))
{
dictReleaseIterator(di);
return 0;
}
}
dictReleaseIterator(di);
return 1;
}
/* Returns true if any previous IO API failed.
* for Load* APIs the REDISMODULE_OPTIONS_HANDLE_IO_ERRORS flag must be set with
* RedisModule_SetModuleOptions first. */
int RM_IsIOError(RedisModuleIO *io) {
return io->error;
}
/* Save an unsigned 64 bit value into the RDB file. This function should only
* be called in the context of the rdb_save method of modules implementing new
* data types. */
void RM_SaveUnsigned(RedisModuleIO *io, uint64_t value) {
if (io->error) return;
/* Save opcode. */
int retval = rdbSaveLen(io->rio, RDB_MODULE_OPCODE_UINT);
if (retval == -1) goto saveerr;
io->bytes += retval;
/* Save value. */
retval = rdbSaveLen(io->rio, value);
if (retval == -1) goto saveerr;
io->bytes += retval;
return;
saveerr:
io->error = 1;
}
/* Load an unsigned 64 bit value from the RDB file. This function should only
* be called in the context of the rdb_load method of modules implementing
* new data types. */
uint64_t RM_LoadUnsigned(RedisModuleIO *io) {
if (io->error) return 0;
if (io->ver == 2) {
uint64_t opcode = rdbLoadLen(io->rio,NULL);
if (opcode != RDB_MODULE_OPCODE_UINT) goto loaderr;
}
uint64_t value;
int retval = rdbLoadLenByRef(io->rio, NULL, &value);
if (retval == -1) goto loaderr;
return value;
loaderr:
moduleRDBLoadError(io);
return 0;
}
/* Like RedisModule_SaveUnsigned() but for signed 64 bit values. */
void RM_SaveSigned(RedisModuleIO *io, int64_t value) {
union {uint64_t u; int64_t i;} conv;
conv.i = value;
RM_SaveUnsigned(io,conv.u);
}
/* Like RedisModule_LoadUnsigned() but for signed 64 bit values. */
int64_t RM_LoadSigned(RedisModuleIO *io) {
union {uint64_t u; int64_t i;} conv;
conv.u = RM_LoadUnsigned(io);
return conv.i;
}
/* In the context of the rdb_save method of a module type, saves a
* string into the RDB file taking as input a RedisModuleString.
*
* The string can be later loaded with RedisModule_LoadString() or
* other Load family functions expecting a serialized string inside
* the RDB file. */
void RM_SaveString(RedisModuleIO *io, RedisModuleString *s) {
if (io->error) return;
/* Save opcode. */
ssize_t retval = rdbSaveLen(io->rio, RDB_MODULE_OPCODE_STRING);
if (retval == -1) goto saveerr;
io->bytes += retval;
/* Save value. */
retval = rdbSaveStringObject(io->rio, s);
if (retval == -1) goto saveerr;
io->bytes += retval;
return;
saveerr:
io->error = 1;
}
/* Like RedisModule_SaveString() but takes a raw C pointer and length
* as input. */
void RM_SaveStringBuffer(RedisModuleIO *io, const char *str, size_t len) {
if (io->error) return;
/* Save opcode. */
ssize_t retval = rdbSaveLen(io->rio, RDB_MODULE_OPCODE_STRING);
if (retval == -1) goto saveerr;
io->bytes += retval;
/* Save value. */
retval = rdbSaveRawString(io->rio, (unsigned char*)str,len);
if (retval == -1) goto saveerr;
io->bytes += retval;
return;
saveerr:
io->error = 1;
}
/* Implements RM_LoadString() and RM_LoadStringBuffer() */
void *moduleLoadString(RedisModuleIO *io, int plain, size_t *lenptr) {
if (io->error) return NULL;
if (io->ver == 2) {
uint64_t opcode = rdbLoadLen(io->rio,NULL);
if (opcode != RDB_MODULE_OPCODE_STRING) goto loaderr;
}
void *s = rdbGenericLoadStringObject(io->rio,
plain ? RDB_LOAD_PLAIN : RDB_LOAD_NONE, lenptr);
if (s == NULL) goto loaderr;
return s;
loaderr:
moduleRDBLoadError(io);
return NULL;
}
/* In the context of the rdb_load method of a module data type, loads a string
* from the RDB file, that was previously saved with RedisModule_SaveString()
* functions family.
*
* The returned string is a newly allocated RedisModuleString object, and
* the user should at some point free it with a call to RedisModule_FreeString().
*
* If the data structure does not store strings as RedisModuleString objects,
* the similar function RedisModule_LoadStringBuffer() could be used instead. */
RedisModuleString *RM_LoadString(RedisModuleIO *io) {
return moduleLoadString(io,0,NULL);
}
/* Like RedisModule_LoadString() but returns an heap allocated string that
* was allocated with RedisModule_Alloc(), and can be resized or freed with
* RedisModule_Realloc() or RedisModule_Free().
*
* The size of the string is stored at '*lenptr' if not NULL.
* The returned string is not automatically NULL terminated, it is loaded
* exactly as it was stored inside the RDB file. */
char *RM_LoadStringBuffer(RedisModuleIO *io, size_t *lenptr) {
return moduleLoadString(io,1,lenptr);
}
/* In the context of the rdb_save method of a module data type, saves a double
* value to the RDB file. The double can be a valid number, a NaN or infinity.
* It is possible to load back the value with RedisModule_LoadDouble(). */
void RM_SaveDouble(RedisModuleIO *io, double value) {
if (io->error) return;
/* Save opcode. */
int retval = rdbSaveLen(io->rio, RDB_MODULE_OPCODE_DOUBLE);
if (retval == -1) goto saveerr;
io->bytes += retval;
/* Save value. */
retval = rdbSaveBinaryDoubleValue(io->rio, value);
if (retval == -1) goto saveerr;
io->bytes += retval;
return;
saveerr:
io->error = 1;
}
/* In the context of the rdb_save method of a module data type, loads back the
* double value saved by RedisModule_SaveDouble(). */
double RM_LoadDouble(RedisModuleIO *io) {
if (io->error) return 0;
if (io->ver == 2) {
uint64_t opcode = rdbLoadLen(io->rio,NULL);
if (opcode != RDB_MODULE_OPCODE_DOUBLE) goto loaderr;
}
double value;
int retval = rdbLoadBinaryDoubleValue(io->rio, &value);
if (retval == -1) goto loaderr;
return value;
loaderr:
moduleRDBLoadError(io);
return 0;
}
/* In the context of the rdb_save method of a module data type, saves a float
* value to the RDB file. The float can be a valid number, a NaN or infinity.
* It is possible to load back the value with RedisModule_LoadFloat(). */
void RM_SaveFloat(RedisModuleIO *io, float value) {
if (io->error) return;
/* Save opcode. */
int retval = rdbSaveLen(io->rio, RDB_MODULE_OPCODE_FLOAT);
if (retval == -1) goto saveerr;
io->bytes += retval;
/* Save value. */
retval = rdbSaveBinaryFloatValue(io->rio, value);
if (retval == -1) goto saveerr;
io->bytes += retval;
return;
saveerr:
io->error = 1;
}
/* In the context of the rdb_save method of a module data type, loads back the
* float value saved by RedisModule_SaveFloat(). */
float RM_LoadFloat(RedisModuleIO *io) {
if (io->error) return 0;
if (io->ver == 2) {
uint64_t opcode = rdbLoadLen(io->rio,NULL);
if (opcode != RDB_MODULE_OPCODE_FLOAT) goto loaderr;
}
float value;
int retval = rdbLoadBinaryFloatValue(io->rio, &value);
if (retval == -1) goto loaderr;
return value;
loaderr:
moduleRDBLoadError(io);
return 0;
}
/* In the context of the rdb_save method of a module data type, saves a long double
* value to the RDB file. The double can be a valid number, a NaN or infinity.
* It is possible to load back the value with RedisModule_LoadLongDouble(). */
void RM_SaveLongDouble(RedisModuleIO *io, long double value) {
if (io->error) return;
char buf[MAX_LONG_DOUBLE_CHARS];
/* Long double has different number of bits in different platforms, so we
* save it as a string type. */
size_t len = ld2string(buf,sizeof(buf),value,LD_STR_HEX);
RM_SaveStringBuffer(io,buf,len);
}
/* In the context of the rdb_save method of a module data type, loads back the
* long double value saved by RedisModule_SaveLongDouble(). */
long double RM_LoadLongDouble(RedisModuleIO *io) {
if (io->error) return 0;
long double value;
size_t len;
char* str = RM_LoadStringBuffer(io,&len);
if (!str) return 0;
string2ld(str,len,&value);
RM_Free(str);
return value;
}
/* Iterate over modules, and trigger rdb aux saving for the ones modules types
* who asked for it. */
ssize_t rdbSaveModulesAux(rio *rdb, int when) {
size_t total_written = 0;
dictIterator *di = dictGetIterator(modules);
dictEntry *de;
while ((de = dictNext(di)) != NULL) {
struct RedisModule *module = dictGetVal(de);
listIter li;
listNode *ln;
listRewind(module->types,&li);
while((ln = listNext(&li))) {
moduleType *mt = ln->value;
if (!mt->aux_save || !(mt->aux_save_triggers & when))
continue;
ssize_t ret = rdbSaveSingleModuleAux(rdb, when, mt);
if (ret==-1) {
dictReleaseIterator(di);
return -1;
}
total_written += ret;
}
}
dictReleaseIterator(di);
return total_written;
}
/* --------------------------------------------------------------------------
* Key digest API (DEBUG DIGEST interface for modules types)
* -------------------------------------------------------------------------- */
/* Add a new element to the digest. This function can be called multiple times
* one element after the other, for all the elements that constitute a given
* data structure. The function call must be followed by the call to
* `RedisModule_DigestEndSequence` eventually, when all the elements that are
* always in a given order are added. See the Redis Modules data types
* documentation for more info. However this is a quick example that uses Redis
* data types as an example.
*
* To add a sequence of unordered elements (for example in the case of a Redis
* Set), the pattern to use is:
*
* foreach element {
* AddElement(element);
* EndSequence();
* }
*
* Because Sets are not ordered, so every element added has a position that
* does not depend from the other. However if instead our elements are
* ordered in pairs, like field-value pairs of an Hash, then one should
* use:
*
* foreach key,value {
* AddElement(key);
* AddElement(value);
* EndSquence();
* }
*
* Because the key and value will be always in the above order, while instead
* the single key-value pairs, can appear in any position into a Redis hash.
*
* A list of ordered elements would be implemented with:
*
* foreach element {
* AddElement(element);
* }
* EndSequence();
*
*/
void RM_DigestAddStringBuffer(RedisModuleDigest *md, unsigned char *ele, size_t len) {
mixDigest(md->o,ele,len);
}
/* Like `RedisModule_DigestAddStringBuffer()` but takes a long long as input
* that gets converted into a string before adding it to the digest. */
void RM_DigestAddLongLong(RedisModuleDigest *md, long long ll) {
char buf[LONG_STR_SIZE];
size_t len = ll2string(buf,sizeof(buf),ll);
mixDigest(md->o,buf,len);
}
/* See the documentation for `RedisModule_DigestAddElement()`. */
void RM_DigestEndSequence(RedisModuleDigest *md) {
xorDigest(md->x,md->o,sizeof(md->o));
memset(md->o,0,sizeof(md->o));
}
/* Decode a serialized representation of a module data type 'mt' from string
* 'str' and return a newly allocated value, or NULL if decoding failed.
*
* This call basically reuses the 'rdb_load' callback which module data types
* implement in order to allow a module to arbitrarily serialize/de-serialize
* keys, similar to how the Redis 'DUMP' and 'RESTORE' commands are implemented.
*
* Modules should generally use the REDISMODULE_OPTIONS_HANDLE_IO_ERRORS flag and
* make sure the de-serialization code properly checks and handles IO errors
* (freeing allocated buffers and returning a NULL).
*
* If this is NOT done, Redis will handle corrupted (or just truncated) serialized
* data by producing an error message and terminating the process.
*/
void *RM_LoadDataTypeFromString(const RedisModuleString *str, const moduleType *mt) {
rio payload;
RedisModuleIO io;
void *ret;
rioInitWithBuffer(&payload, str->ptr);
moduleInitIOContext(io,(moduleType *)mt,&payload,NULL);
/* All RM_Save*() calls always write a version 2 compatible format, so we
* need to make sure we read the same.
*/
io.ver = 2;
ret = mt->rdb_load(&io,0);
if (io.ctx) {
moduleFreeContext(io.ctx);
zfree(io.ctx);
}
return ret;
}
/* Encode a module data type 'mt' value 'data' into serialized form, and return it
* as a newly allocated RedisModuleString.
*
* This call basically reuses the 'rdb_save' callback which module data types
* implement in order to allow a module to arbitrarily serialize/de-serialize
* keys, similar to how the Redis 'DUMP' and 'RESTORE' commands are implemented.
*/
RedisModuleString *RM_SaveDataTypeToString(RedisModuleCtx *ctx, void *data, const moduleType *mt) {
rio payload;
RedisModuleIO io;
rioInitWithBuffer(&payload,sdsempty());
moduleInitIOContext(io,(moduleType *)mt,&payload,NULL);
mt->rdb_save(&io,data);
if (io.ctx) {
moduleFreeContext(io.ctx);
zfree(io.ctx);
}
if (io.error) {
return NULL;
} else {
robj *str = createObject(OBJ_STRING,payload.io.buffer.ptr);
if (ctx != NULL) autoMemoryAdd(ctx,REDISMODULE_AM_STRING,str);
return str;
}
}
/* --------------------------------------------------------------------------
* AOF API for modules data types
* -------------------------------------------------------------------------- */
/* Emits a command into the AOF during the AOF rewriting process. This function
* is only called in the context of the aof_rewrite method of data types exported
* by a module. The command works exactly like RedisModule_Call() in the way
* the parameters are passed, but it does not return anything as the error
* handling is performed by Redis itself. */
void RM_EmitAOF(RedisModuleIO *io, const char *cmdname, const char *fmt, ...) {
if (io->error) return;
struct redisCommand *cmd;
robj **argv = NULL;
int argc = 0, flags = 0, j;
va_list ap;
cmd = lookupCommandByCString((char*)cmdname);
if (!cmd) {
serverLog(LL_WARNING,
"Fatal: AOF method for module data type '%s' tried to "
"emit unknown command '%s'",
io->type->name, cmdname);
io->error = 1;
errno = EINVAL;
return;
}
/* Emit the arguments into the AOF in Redis protocol format. */
va_start(ap, fmt);
argv = moduleCreateArgvFromUserFormat(cmdname,fmt,&argc,&flags,ap);
va_end(ap);
if (argv == NULL) {
serverLog(LL_WARNING,
"Fatal: AOF method for module data type '%s' tried to "
"call RedisModule_EmitAOF() with wrong format specifiers '%s'",
io->type->name, fmt);
io->error = 1;
errno = EINVAL;
return;
}
/* Bulk count. */
if (!io->error && rioWriteBulkCount(io->rio,'*',argc) == 0)
io->error = 1;
/* Arguments. */
for (j = 0; j < argc; j++) {
if (!io->error && rioWriteBulkObject(io->rio,argv[j]) == 0)
io->error = 1;
decrRefCount(argv[j]);
}
zfree(argv);
return;
}
/* --------------------------------------------------------------------------
* IO context handling
* -------------------------------------------------------------------------- */
RedisModuleCtx *RM_GetContextFromIO(RedisModuleIO *io) {
if (io->ctx) return io->ctx; /* Can't have more than one... */
RedisModuleCtx ctxtemplate = REDISMODULE_CTX_INIT;
io->ctx = zmalloc(sizeof(RedisModuleCtx));
*(io->ctx) = ctxtemplate;
io->ctx->module = io->type->module;
io->ctx->client = NULL;
return io->ctx;
}
/* Returns a RedisModuleString with the name of the key currently saving or
* loading, when an IO data type callback is called. There is no guarantee
* that the key name is always available, so this may return NULL.
*/
const RedisModuleString *RM_GetKeyNameFromIO(RedisModuleIO *io) {
return io->key;
}
/* Returns a RedisModuleString with the name of the key from RedisModuleKey */
const RedisModuleString *RM_GetKeyNameFromModuleKey(RedisModuleKey *key) {
return key ? key->key : NULL;
}
/* --------------------------------------------------------------------------
* Logging
* -------------------------------------------------------------------------- */
/* This is the low level function implementing both:
*
* RM_Log()
* RM_LogIOError()
*
*/
void RM_LogRaw(RedisModule *module, const char *levelstr, const char *fmt, va_list ap) {
char msg[LOG_MAX_LEN];
size_t name_len;
int level;
if (!strcasecmp(levelstr,"debug")) level = LL_DEBUG;
else if (!strcasecmp(levelstr,"verbose")) level = LL_VERBOSE;
else if (!strcasecmp(levelstr,"notice")) level = LL_NOTICE;
else if (!strcasecmp(levelstr,"warning")) level = LL_WARNING;
else level = LL_VERBOSE; /* Default. */
if (level < server.verbosity) return;
name_len = snprintf(msg, sizeof(msg),"<%s> ", module? module->name: "module");
vsnprintf(msg + name_len, sizeof(msg) - name_len, fmt, ap);
serverLogRaw(level,msg);
}
/* Produces a log message to the standard Redis log, the format accepts
* printf-alike specifiers, while level is a string describing the log
* level to use when emitting the log, and must be one of the following:
*
* * "debug"
* * "verbose"
* * "notice"
* * "warning"
*
* If the specified log level is invalid, verbose is used by default.
* There is a fixed limit to the length of the log line this function is able
* to emit, this limit is not specified but is guaranteed to be more than
* a few lines of text.
*
* The ctx argument may be NULL if cannot be provided in the context of the
* caller for instance threads or callbacks, in which case a generic "module"
* will be used instead of the module name.
*/
void RM_Log(RedisModuleCtx *ctx, const char *levelstr, const char *fmt, ...) {
va_list ap;
va_start(ap, fmt);
RM_LogRaw(ctx? ctx->module: NULL,levelstr,fmt,ap);
va_end(ap);
}
/* Log errors from RDB / AOF serialization callbacks.
*
* This function should be used when a callback is returning a critical
* error to the caller since cannot load or save the data for some
* critical reason. */
void RM_LogIOError(RedisModuleIO *io, const char *levelstr, const char *fmt, ...) {
va_list ap;
va_start(ap, fmt);
RM_LogRaw(io->type->module,levelstr,fmt,ap);
va_end(ap);
}
/* Redis-like assert function.
*
* A failed assertion will shut down the server and produce logging information
* that looks identical to information generated by Redis itself.
*/
void RM__Assert(const char *estr, const char *file, int line) {
_serverAssert(estr, file, line);
}
/* Allows adding event to the latency monitor to be observed by the LATENCY
* command. The call is skipped if the latency is smaller than the configured
* latency-monitor-threshold. */
void RM_LatencyAddSample(const char *event, mstime_t latency) {
if (latency >= server.latency_monitor_threshold)
latencyAddSample(event, latency);
}
/* --------------------------------------------------------------------------
* Blocking clients from modules
* -------------------------------------------------------------------------- */
/* Readable handler for the awake pipe. We do nothing here, the awake bytes
* will be actually read in a more appropriate place in the
* moduleHandleBlockedClients() function that is where clients are actually
* served. */
void moduleBlockedClientPipeReadable(aeEventLoop *el, int fd, void *privdata, int mask) {
UNUSED(el);
UNUSED(fd);
UNUSED(mask);
UNUSED(privdata);
}
/* This is called from blocked.c in order to unblock a client: may be called
* for multiple reasons while the client is in the middle of being blocked
* because the client is terminated, but is also called for cleanup when a
* client is unblocked in a clean way after replaying.
*
* What we do here is just to set the client to NULL in the redis module
* blocked client handle. This way if the client is terminated while there
* is a pending threaded operation involving the blocked client, we'll know
* that the client no longer exists and no reply callback should be called.
*
* The structure RedisModuleBlockedClient will be always deallocated when
* running the list of clients blocked by a module that need to be unblocked. */
void unblockClientFromModule(client *c) {
RedisModuleBlockedClient *bc = c->bpop.module_blocked_handle;
/* Call the disconnection callback if any. Note that
* bc->disconnect_callback is set to NULL if the client gets disconnected
* by the module itself or because of a timeout, so the callback will NOT
* get called if this is not an actual disconnection event. */
if (bc->disconnect_callback) {
RedisModuleCtx ctx = REDISMODULE_CTX_INIT;
ctx.blocked_privdata = bc->privdata;
ctx.module = bc->module;
ctx.client = bc->client;
bc->disconnect_callback(&ctx,bc);
moduleFreeContext(&ctx);
}
/* If we made it here and client is still blocked it means that the command
* timed-out, client was killed or disconnected and disconnect_callback was
* not implemented (or it was, but RM_UnblockClient was not called from
* within it, as it should).
* We must call moduleUnblockClient in order to free privdata and
* RedisModuleBlockedClient.
*
* Note that we only do that for clients that are blocked on keys, for which
* the contract is that the module should not call RM_UnblockClient under
* normal circumstances.
* Clients implementing threads and working with private data should be
* aware that calling RM_UnblockClient for every blocked client is their
* responsibility, and if they fail to do so memory may leak. Ideally they
* should implement the disconnect and timeout callbacks and call
* RM_UnblockClient, but any other way is also acceptable. */
if (bc->blocked_on_keys && !bc->unblocked)
moduleUnblockClient(c);
bc->client = NULL;
/* Reset the client for a new query since, for blocking commands implemented
* into modules, we do not it immediately after the command returns (and
* the client blocks) in order to be still able to access the argument
* vector from callbacks. */
resetClient(c);
}
/* Block a client in the context of a module: this function implements both
* RM_BlockClient() and RM_BlockClientOnKeys() depending on the fact the
* keys are passed or not.
*
* When not blocking for keys, the keys, numkeys, and privdata parameters are
* not needed. The privdata in that case must be NULL, since later is
* RM_UnblockClient() that will provide some private data that the reply
* callback will receive.
*
* Instead when blocking for keys, normally RM_UnblockClient() will not be
* called (because the client will unblock when the key is modified), so
* 'privdata' should be provided in that case, so that once the client is
* unlocked and the reply callback is called, it will receive its associated
* private data.
*
* Even when blocking on keys, RM_UnblockClient() can be called however, but
* in that case the privdata argument is disregarded, because we pass the
* reply callback the privdata that is set here while blocking.
*
*/
RedisModuleBlockedClient *moduleBlockClient(RedisModuleCtx *ctx, RedisModuleCmdFunc reply_callback, RedisModuleCmdFunc timeout_callback, void (*free_privdata)(RedisModuleCtx*,void*), long long timeout_ms, RedisModuleString **keys, int numkeys, void *privdata) {
client *c = ctx->client;
int islua = c->flags & CLIENT_LUA;
int ismulti = c->flags & CLIENT_MULTI;
c->bpop.module_blocked_handle = zmalloc(sizeof(RedisModuleBlockedClient));
RedisModuleBlockedClient *bc = c->bpop.module_blocked_handle;
ctx->module->blocked_clients++;
/* We need to handle the invalid operation of calling modules blocking
* commands from Lua or MULTI. We actually create an already aborted
* (client set to NULL) blocked client handle, and actually reply with
* an error. */
mstime_t timeout = timeout_ms ? (mstime()+timeout_ms) : 0;
bc->client = (islua || ismulti) ? NULL : c;
bc->module = ctx->module;
bc->reply_callback = reply_callback;
bc->timeout_callback = timeout_callback;
bc->disconnect_callback = NULL; /* Set by RM_SetDisconnectCallback() */
bc->free_privdata = free_privdata;
bc->privdata = privdata;
bc->reply_client = createClient(NULL);
bc->reply_client->flags |= CLIENT_MODULE;
bc->dbid = c->db->id;
bc->blocked_on_keys = keys != NULL;
bc->unblocked = 0;
c->bpop.timeout = timeout;
if (islua || ismulti) {
c->bpop.module_blocked_handle = NULL;
addReplyError(c, islua ?
"Blocking module command called from Lua script" :
"Blocking module command called from transaction");
} else {
if (keys) {
blockForKeys(c,BLOCKED_MODULE,keys,numkeys,timeout,NULL,NULL);
} else {
blockClient(c,BLOCKED_MODULE);
}
}
return bc;
}
/* This function is called from module.c in order to check if a module
* blocked for BLOCKED_MODULE and subtype 'on keys' (bc->blocked_on_keys true)
* can really be unblocked, since the module was able to serve the client.
* If the callback returns REDISMODULE_OK, then the client can be unblocked,
* otherwise the client remains blocked and we'll retry again when one of
* the keys it blocked for becomes "ready" again.
* This function returns 1 if client was served (and should be unblocked) */
int moduleTryServeClientBlockedOnKey(client *c, robj *key) {
int served = 0;
RedisModuleBlockedClient *bc = c->bpop.module_blocked_handle;
/* Protect against re-processing: don't serve clients that are already
* in the unblocking list for any reason (including RM_UnblockClient()
* explicit call). See #6798. */
if (bc->unblocked) return 0;
RedisModuleCtx ctx = REDISMODULE_CTX_INIT;
ctx.flags |= REDISMODULE_CTX_BLOCKED_REPLY;
ctx.blocked_ready_key = key;
ctx.blocked_privdata = bc->privdata;
ctx.module = bc->module;
ctx.client = bc->client;
ctx.blocked_client = bc;
if (bc->reply_callback(&ctx,(void**)c->argv,c->argc) == REDISMODULE_OK)
served = 1;
moduleFreeContext(&ctx);
return served;
}
/* Block a client in the context of a blocking command, returning an handle
* which will be used, later, in order to unblock the client with a call to
* RedisModule_UnblockClient(). The arguments specify callback functions
* and a timeout after which the client is unblocked.
*
* The callbacks are called in the following contexts:
*
* reply_callback: called after a successful RedisModule_UnblockClient()
* call in order to reply to the client and unblock it.
*
* timeout_callback: called when the timeout is reached in order to send an
* error to the client.
*
* free_privdata: called in order to free the private data that is passed
* by RedisModule_UnblockClient() call.
*
* Note: RedisModule_UnblockClient should be called for every blocked client,
* even if client was killed, timed-out or disconnected. Failing to do so
* will result in memory leaks.
*
* There are some cases where RedisModule_BlockClient() cannot be used:
*
* 1. If the client is a Lua script.
* 2. If the client is executing a MULTI block.
*
* In these cases, a call to RedisModule_BlockClient() will **not** block the
* client, but instead produce a specific error reply.
*/
RedisModuleBlockedClient *RM_BlockClient(RedisModuleCtx *ctx, RedisModuleCmdFunc reply_callback, RedisModuleCmdFunc timeout_callback, void (*free_privdata)(RedisModuleCtx*,void*), long long timeout_ms) {
return moduleBlockClient(ctx,reply_callback,timeout_callback,free_privdata,timeout_ms, NULL,0,NULL);
}
/* This call is similar to RedisModule_BlockClient(), however in this case we
* don't just block the client, but also ask Redis to unblock it automatically
* once certain keys become "ready", that is, contain more data.
*
* Basically this is similar to what a typical Redis command usually does,
* like BLPOP or BZPOPMAX: the client blocks if it cannot be served ASAP,
* and later when the key receives new data (a list push for instance), the
* client is unblocked and served.
*
* However in the case of this module API, when the client is unblocked?
*
* 1. If you block on a key of a type that has blocking operations associated,
* like a list, a sorted set, a stream, and so forth, the client may be
* unblocked once the relevant key is targeted by an operation that normally
* unblocks the native blocking operations for that type. So if we block
* on a list key, an RPUSH command may unblock our client and so forth.
* 2. If you are implementing your native data type, or if you want to add new
* unblocking conditions in addition to "1", you can call the modules API
* RedisModule_SignalKeyAsReady().
*
* Anyway we can't be sure if the client should be unblocked just because the
* key is signaled as ready: for instance a successive operation may change the
* key, or a client in queue before this one can be served, modifying the key
* as well and making it empty again. So when a client is blocked with
* RedisModule_BlockClientOnKeys() the reply callback is not called after
* RM_UnblockCLient() is called, but every time a key is signaled as ready:
* if the reply callback can serve the client, it returns REDISMODULE_OK
* and the client is unblocked, otherwise it will return REDISMODULE_ERR
* and we'll try again later.
*
* The reply callback can access the key that was signaled as ready by
* calling the API RedisModule_GetBlockedClientReadyKey(), that returns
* just the string name of the key as a RedisModuleString object.
*
* Thanks to this system we can setup complex blocking scenarios, like
* unblocking a client only if a list contains at least 5 items or other
* more fancy logics.
*
* Note that another difference with RedisModule_BlockClient(), is that here
* we pass the private data directly when blocking the client: it will
* be accessible later in the reply callback. Normally when blocking with
* RedisModule_BlockClient() the private data to reply to the client is
* passed when calling RedisModule_UnblockClient() but here the unblocking
* is performed by Redis itself, so we need to have some private data before
* hand. The private data is used to store any information about the specific
* unblocking operation that you are implementing. Such information will be
* freed using the free_privdata callback provided by the user.
*
* However the reply callback will be able to access the argument vector of
* the command, so the private data is often not needed.
*
* Note: Under normal circumstances RedisModule_UnblockClient should not be
* called for clients that are blocked on keys (Either the key will
* become ready or a timeout will occur). If for some reason you do want
* to call RedisModule_UnblockClient it is possible: Client will be
* handled as if it were timed-out (You must implement the timeout
* callback in that case).
*/
RedisModuleBlockedClient *RM_BlockClientOnKeys(RedisModuleCtx *ctx, RedisModuleCmdFunc reply_callback, RedisModuleCmdFunc timeout_callback, void (*free_privdata)(RedisModuleCtx*,void*), long long timeout_ms, RedisModuleString **keys, int numkeys, void *privdata) {
return moduleBlockClient(ctx,reply_callback,timeout_callback,free_privdata,timeout_ms, keys,numkeys,privdata);
}
/* This function is used in order to potentially unblock a client blocked
* on keys with RedisModule_BlockClientOnKeys(). When this function is called,
* all the clients blocked for this key will get their reply callback called,
* and if the callback returns REDISMODULE_OK the client will be unblocked. */
void RM_SignalKeyAsReady(RedisModuleCtx *ctx, RedisModuleString *key) {
signalKeyAsReady(ctx->client->db, key, OBJ_MODULE);
}
/* Implements RM_UnblockClient() and moduleUnblockClient(). */
int moduleUnblockClientByHandle(RedisModuleBlockedClient *bc, void *privdata) {
pthread_mutex_lock(&moduleUnblockedClientsMutex);
if (!bc->blocked_on_keys) bc->privdata = privdata;
bc->unblocked = 1;
listAddNodeTail(moduleUnblockedClients,bc);
if (write(server.module_blocked_pipe[1],"A",1) != 1) {
/* Ignore the error, this is best-effort. */
}
pthread_mutex_unlock(&moduleUnblockedClientsMutex);
return REDISMODULE_OK;
}
/* This API is used by the Redis core to unblock a client that was blocked
* by a module. */
void moduleUnblockClient(client *c) {
RedisModuleBlockedClient *bc = c->bpop.module_blocked_handle;
moduleUnblockClientByHandle(bc,NULL);
}
/* Return true if the client 'c' was blocked by a module using
* RM_BlockClientOnKeys(). */
int moduleClientIsBlockedOnKeys(client *c) {
RedisModuleBlockedClient *bc = c->bpop.module_blocked_handle;
return bc->blocked_on_keys;
}
/* Unblock a client blocked by `RedisModule_BlockedClient`. This will trigger
* the reply callbacks to be called in order to reply to the client.
* The 'privdata' argument will be accessible by the reply callback, so
* the caller of this function can pass any value that is needed in order to
* actually reply to the client.
*
* A common usage for 'privdata' is a thread that computes something that
* needs to be passed to the client, included but not limited some slow
* to compute reply or some reply obtained via networking.
*
* Note 1: this function can be called from threads spawned by the module.
*
* Note 2: when we unblock a client that is blocked for keys using
* the API RedisModule_BlockClientOnKeys(), the privdata argument here is
* not used, and the reply callback is called with the privdata pointer that
* was passed when blocking the client.
*
* Unblocking a client that was blocked for keys using this API will still
* require the client to get some reply, so the function will use the
* "timeout" handler in order to do so. */
int RM_UnblockClient(RedisModuleBlockedClient *bc, void *privdata) {
if (bc->blocked_on_keys) {
/* In theory the user should always pass the timeout handler as an
* argument, but better to be safe than sorry. */
if (bc->timeout_callback == NULL) return REDISMODULE_ERR;
if (bc->unblocked) return REDISMODULE_OK;
if (bc->client) moduleBlockedClientTimedOut(bc->client);
}
moduleUnblockClientByHandle(bc,privdata);
return REDISMODULE_OK;
}
/* Abort a blocked client blocking operation: the client will be unblocked
* without firing any callback. */
int RM_AbortBlock(RedisModuleBlockedClient *bc) {
bc->reply_callback = NULL;
bc->disconnect_callback = NULL;
return RM_UnblockClient(bc,NULL);
}
/* Set a callback that will be called if a blocked client disconnects
* before the module has a chance to call RedisModule_UnblockClient()
*
* Usually what you want to do there, is to cleanup your module state
* so that you can call RedisModule_UnblockClient() safely, otherwise
* the client will remain blocked forever if the timeout is large.
*
* Notes:
*
* 1. It is not safe to call Reply* family functions here, it is also
* useless since the client is gone.
*
* 2. This callback is not called if the client disconnects because of
* a timeout. In such a case, the client is unblocked automatically
* and the timeout callback is called.
*/
void RM_SetDisconnectCallback(RedisModuleBlockedClient *bc, RedisModuleDisconnectFunc callback) {
bc->disconnect_callback = callback;
}
/* This function will check the moduleUnblockedClients queue in order to
* call the reply callback and really unblock the client.
*
* Clients end into this list because of calls to RM_UnblockClient(),
* however it is possible that while the module was doing work for the
* blocked client, it was terminated by Redis (for timeout or other reasons).
* When this happens the RedisModuleBlockedClient structure in the queue
* will have the 'client' field set to NULL. */
void moduleHandleBlockedClients(void) {
listNode *ln;
RedisModuleBlockedClient *bc;
pthread_mutex_lock(&moduleUnblockedClientsMutex);
/* Here we unblock all the pending clients blocked in modules operations
* so we can read every pending "awake byte" in the pipe. */
char buf[1];
while (read(server.module_blocked_pipe[0],buf,1) == 1);
while (listLength(moduleUnblockedClients)) {
ln = listFirst(moduleUnblockedClients);
bc = ln->value;
client *c = bc->client;
listDelNode(moduleUnblockedClients,ln);
pthread_mutex_unlock(&moduleUnblockedClientsMutex);
/* Release the lock during the loop, as long as we don't
* touch the shared list. */
/* Call the reply callback if the client is valid and we have
* any callback. However the callback is not called if the client
* was blocked on keys (RM_BlockClientOnKeys()), because we already
* called such callback in moduleTryServeClientBlockedOnKey() when
* the key was signaled as ready. */
if (c && !bc->blocked_on_keys && bc->reply_callback) {
RedisModuleCtx ctx = REDISMODULE_CTX_INIT;
ctx.flags |= REDISMODULE_CTX_BLOCKED_REPLY;
ctx.blocked_privdata = bc->privdata;
ctx.blocked_ready_key = NULL;
ctx.module = bc->module;
ctx.client = bc->client;
ctx.blocked_client = bc;
bc->reply_callback(&ctx,(void**)c->argv,c->argc);
moduleFreeContext(&ctx);
}
/* Free privdata if any. */
if (bc->privdata && bc->free_privdata) {
RedisModuleCtx ctx = REDISMODULE_CTX_INIT;
if (c == NULL)
ctx.flags |= REDISMODULE_CTX_BLOCKED_DISCONNECTED;
ctx.blocked_privdata = bc->privdata;
ctx.module = bc->module;
ctx.client = bc->client;
bc->free_privdata(&ctx,bc->privdata);
moduleFreeContext(&ctx);
}
/* It is possible that this blocked client object accumulated
* replies to send to the client in a thread safe context.
* We need to glue such replies to the client output buffer and
* free the temporary client we just used for the replies. */
if (c) AddReplyFromClient(c, bc->reply_client);
freeClient(bc->reply_client);
if (c != NULL) {
/* Before unblocking the client, set the disconnect callback
* to NULL, because if we reached this point, the client was
* properly unblocked by the module. */
bc->disconnect_callback = NULL;
unblockClient(c);
/* Put the client in the list of clients that need to write
* if there are pending replies here. This is needed since
* during a non blocking command the client may receive output. */
if (clientHasPendingReplies(c) &&
!(c->flags & CLIENT_PENDING_WRITE))
{
c->flags |= CLIENT_PENDING_WRITE;
listAddNodeHead(server.clients_pending_write,c);
}
}
/* Free 'bc' only after unblocking the client, since it is
* referenced in the client blocking context, and must be valid
* when calling unblockClient(). */
bc->module->blocked_clients--;
zfree(bc);
/* Lock again before to iterate the loop. */
pthread_mutex_lock(&moduleUnblockedClientsMutex);
}
pthread_mutex_unlock(&moduleUnblockedClientsMutex);
}
/* Called when our client timed out. After this function unblockClient()
* is called, and it will invalidate the blocked client. So this function
* does not need to do any cleanup. Eventually the module will call the
* API to unblock the client and the memory will be released. */
void moduleBlockedClientTimedOut(client *c) {
RedisModuleBlockedClient *bc = c->bpop.module_blocked_handle;
RedisModuleCtx ctx = REDISMODULE_CTX_INIT;
ctx.flags |= REDISMODULE_CTX_BLOCKED_TIMEOUT;
ctx.module = bc->module;
ctx.client = bc->client;
ctx.blocked_client = bc;
bc->timeout_callback(&ctx,(void**)c->argv,c->argc);
moduleFreeContext(&ctx);
/* For timeout events, we do not want to call the disconnect callback,
* because the blocked client will be automatically disconnected in
* this case, and the user can still hook using the timeout callback. */
bc->disconnect_callback = NULL;
}
/* Return non-zero if a module command was called in order to fill the
* reply for a blocked client. */
int RM_IsBlockedReplyRequest(RedisModuleCtx *ctx) {
return (ctx->flags & REDISMODULE_CTX_BLOCKED_REPLY) != 0;
}
/* Return non-zero if a module command was called in order to fill the
* reply for a blocked client that timed out. */
int RM_IsBlockedTimeoutRequest(RedisModuleCtx *ctx) {
return (ctx->flags & REDISMODULE_CTX_BLOCKED_TIMEOUT) != 0;
}
/* Get the private data set by RedisModule_UnblockClient() */
void *RM_GetBlockedClientPrivateData(RedisModuleCtx *ctx) {
return ctx->blocked_privdata;
}
/* Get the key that is ready when the reply callback is called in the context
* of a client blocked by RedisModule_BlockClientOnKeys(). */
RedisModuleString *RM_GetBlockedClientReadyKey(RedisModuleCtx *ctx) {
return ctx->blocked_ready_key;
}
/* Get the blocked client associated with a given context.
* This is useful in the reply and timeout callbacks of blocked clients,
* before sometimes the module has the blocked client handle references
* around, and wants to cleanup it. */
RedisModuleBlockedClient *RM_GetBlockedClientHandle(RedisModuleCtx *ctx) {
return ctx->blocked_client;
}
/* Return true if when the free callback of a blocked client is called,
* the reason for the client to be unblocked is that it disconnected
* while it was blocked. */
int RM_BlockedClientDisconnected(RedisModuleCtx *ctx) {
return (ctx->flags & REDISMODULE_CTX_BLOCKED_DISCONNECTED) != 0;
}
/* --------------------------------------------------------------------------
* Thread Safe Contexts
* -------------------------------------------------------------------------- */
/* Return a context which can be used inside threads to make Redis context
* calls with certain modules APIs. If 'bc' is not NULL then the module will
* be bound to a blocked client, and it will be possible to use the
* `RedisModule_Reply*` family of functions to accumulate a reply for when the
* client will be unblocked. Otherwise the thread safe context will be
* detached by a specific client.
*
* To call non-reply APIs, the thread safe context must be prepared with:
*
* RedisModule_ThreadSafeContextLock(ctx);
* ... make your call here ...
* RedisModule_ThreadSafeContextUnlock(ctx);
*
* This is not needed when using `RedisModule_Reply*` functions, assuming
* that a blocked client was used when the context was created, otherwise
* no RedisModule_Reply* call should be made at all.
*
* TODO: thread safe contexts do not inherit the blocked client
* selected database. */
RedisModuleCtx *RM_GetThreadSafeContext(RedisModuleBlockedClient *bc) {
RedisModuleCtx *ctx = zmalloc(sizeof(*ctx));
RedisModuleCtx empty = REDISMODULE_CTX_INIT;
memcpy(ctx,&empty,sizeof(empty));
if (bc) {
ctx->blocked_client = bc;
ctx->module = bc->module;
}
ctx->flags |= REDISMODULE_CTX_THREAD_SAFE;
/* Even when the context is associated with a blocked client, we can't
* access it safely from another thread, so we create a fake client here
* in order to keep things like the currently selected database and similar
* things. */
ctx->client = createClient(NULL);
if (bc) {
selectDb(ctx->client,bc->dbid);
if (bc->client) ctx->client->id = bc->client->id;
}
return ctx;
}
/* Release a thread safe context. */
void RM_FreeThreadSafeContext(RedisModuleCtx *ctx) {
moduleFreeContext(ctx);
zfree(ctx);
}
/* Acquire the server lock before executing a thread safe API call.
* This is not needed for `RedisModule_Reply*` calls when there is
* a blocked client connected to the thread safe context. */
void RM_ThreadSafeContextLock(RedisModuleCtx *ctx) {
UNUSED(ctx);
moduleAcquireGIL();
}
/* Similar to RM_ThreadSafeContextLock but this function
* would not block if the server lock is already acquired.
*
* If successful (lock acquired) REDISMODULE_OK is returned,
* otherwise REDISMODULE_ERR is returned and errno is set
* accordingly. */
int RM_ThreadSafeContextTryLock(RedisModuleCtx *ctx) {
UNUSED(ctx);
int res = moduleTryAcquireGIL();
if(res != 0) {
errno = res;
return REDISMODULE_ERR;
}
return REDISMODULE_OK;
}
/* Release the server lock after a thread safe API call was executed. */
void RM_ThreadSafeContextUnlock(RedisModuleCtx *ctx) {
UNUSED(ctx);
moduleReleaseGIL();
}
void moduleAcquireGIL(void) {
pthread_mutex_lock(&moduleGIL);
}
int moduleTryAcquireGIL(void) {
return pthread_mutex_trylock(&moduleGIL);
}
void moduleReleaseGIL(void) {
pthread_mutex_unlock(&moduleGIL);
}
/* --------------------------------------------------------------------------
* Module Keyspace Notifications API
* -------------------------------------------------------------------------- */
/* Subscribe to keyspace notifications. This is a low-level version of the
* keyspace-notifications API. A module can register callbacks to be notified
* when keyspace events occur.
*
* Notification events are filtered by their type (string events, set events,
* etc), and the subscriber callback receives only events that match a specific
* mask of event types.
*
* When subscribing to notifications with RedisModule_SubscribeToKeyspaceEvents
* the module must provide an event type-mask, denoting the events the subscriber
* is interested in. This can be an ORed mask of any of the following flags:
*
* - REDISMODULE_NOTIFY_GENERIC: Generic commands like DEL, EXPIRE, RENAME
* - REDISMODULE_NOTIFY_STRING: String events
* - REDISMODULE_NOTIFY_LIST: List events
* - REDISMODULE_NOTIFY_SET: Set events
* - REDISMODULE_NOTIFY_HASH: Hash events
* - REDISMODULE_NOTIFY_ZSET: Sorted Set events
* - REDISMODULE_NOTIFY_EXPIRED: Expiration events
* - REDISMODULE_NOTIFY_EVICTED: Eviction events
* - REDISMODULE_NOTIFY_STREAM: Stream events
* - REDISMODULE_NOTIFY_KEYMISS: Key-miss events
* - REDISMODULE_NOTIFY_ALL: All events (Excluding REDISMODULE_NOTIFY_KEYMISS)
* - REDISMODULE_NOTIFY_LOADED: A special notification available only for modules,
* indicates that the key was loaded from persistence.
* Notice, when this event fires, the given key
* can not be retained, use RM_CreateStringFromString
* instead.
*
* We do not distinguish between key events and keyspace events, and it is up
* to the module to filter the actions taken based on the key.
*
* The subscriber signature is:
*
* int (*RedisModuleNotificationFunc) (RedisModuleCtx *ctx, int type,
* const char *event,
* RedisModuleString *key);
*
* `type` is the event type bit, that must match the mask given at registration
* time. The event string is the actual command being executed, and key is the
* relevant Redis key.
*
* Notification callback gets executed with a redis context that can not be
* used to send anything to the client, and has the db number where the event
* occurred as its selected db number.
*
* Notice that it is not necessary to enable notifications in redis.conf for
* module notifications to work.
*
* Warning: the notification callbacks are performed in a synchronous manner,
* so notification callbacks must to be fast, or they would slow Redis down.
* If you need to take long actions, use threads to offload them.
*
* See https://redis.io/topics/notifications for more information.
*/
int RM_SubscribeToKeyspaceEvents(RedisModuleCtx *ctx, int types, RedisModuleNotificationFunc callback) {
RedisModuleKeyspaceSubscriber *sub = zmalloc(sizeof(*sub));
sub->module = ctx->module;
sub->event_mask = types;
sub->notify_callback = callback;
sub->active = 0;
listAddNodeTail(moduleKeyspaceSubscribers, sub);
return REDISMODULE_OK;
}
/* Get the configured bitmap of notify-keyspace-events (Could be used
* for additional filtering in RedisModuleNotificationFunc) */
int RM_GetNotifyKeyspaceEvents() {
return server.notify_keyspace_events;
}
/* Expose notifyKeyspaceEvent to modules */
int RM_NotifyKeyspaceEvent(RedisModuleCtx *ctx, int type, const char *event, RedisModuleString *key) {
if (!ctx || !ctx->client)
return REDISMODULE_ERR;
notifyKeyspaceEvent(type, (char *)event, key, ctx->client->db->id);
return REDISMODULE_OK;
}
/* Dispatcher for keyspace notifications to module subscriber functions.
* This gets called only if at least one module requested to be notified on
* keyspace notifications */
void moduleNotifyKeyspaceEvent(int type, const char *event, robj *key, int dbid) {
/* Don't do anything if there aren't any subscribers */
if (listLength(moduleKeyspaceSubscribers) == 0) return;
listIter li;
listNode *ln;
listRewind(moduleKeyspaceSubscribers,&li);
/* Remove irrelevant flags from the type mask */
type &= ~(NOTIFY_KEYEVENT | NOTIFY_KEYSPACE);
while((ln = listNext(&li))) {
RedisModuleKeyspaceSubscriber *sub = ln->value;
/* Only notify subscribers on events matching they registration,
* and avoid subscribers triggering themselves */
if ((sub->event_mask & type) && sub->active == 0) {
RedisModuleCtx ctx = REDISMODULE_CTX_INIT;
ctx.module = sub->module;
ctx.client = moduleFreeContextReusedClient;
selectDb(ctx.client, dbid);
/* mark the handler as active to avoid reentrant loops.
* If the subscriber performs an action triggering itself,
* it will not be notified about it. */
sub->active = 1;
sub->notify_callback(&ctx, type, event, key);
sub->active = 0;
moduleFreeContext(&ctx);
}
}
}
/* Unsubscribe any notification subscribers this module has upon unloading */
void moduleUnsubscribeNotifications(RedisModule *module) {
listIter li;
listNode *ln;
listRewind(moduleKeyspaceSubscribers,&li);
while((ln = listNext(&li))) {
RedisModuleKeyspaceSubscriber *sub = ln->value;
if (sub->module == module) {
listDelNode(moduleKeyspaceSubscribers, ln);
zfree(sub);
}
}
}
/* --------------------------------------------------------------------------
* Modules Cluster API
* -------------------------------------------------------------------------- */
/* The Cluster message callback function pointer type. */
typedef void (*RedisModuleClusterMessageReceiver)(RedisModuleCtx *ctx, const char *sender_id, uint8_t type, const unsigned char *payload, uint32_t len);
/* This structure identifies a registered caller: it must match a given module
* ID, for a given message type. The callback function is just the function
* that was registered as receiver. */
typedef struct moduleClusterReceiver {
uint64_t module_id;
RedisModuleClusterMessageReceiver callback;
struct RedisModule *module;
struct moduleClusterReceiver *next;
} moduleClusterReceiver;
typedef struct moduleClusterNodeInfo {
int flags;
char ip[NET_IP_STR_LEN];
int port;
char master_id[40]; /* Only if flags & REDISMODULE_NODE_MASTER is true. */
} mdouleClusterNodeInfo;
/* We have an array of message types: each bucket is a linked list of
* configured receivers. */
static moduleClusterReceiver *clusterReceivers[UINT8_MAX];
/* Dispatch the message to the right module receiver. */
void moduleCallClusterReceivers(const char *sender_id, uint64_t module_id, uint8_t type, const unsigned char *payload, uint32_t len) {
moduleClusterReceiver *r = clusterReceivers[type];
while(r) {
if (r->module_id == module_id) {
RedisModuleCtx ctx = REDISMODULE_CTX_INIT;
ctx.module = r->module;
ctx.client = moduleFreeContextReusedClient;
selectDb(ctx.client, 0);
r->callback(&ctx,sender_id,type,payload,len);
moduleFreeContext(&ctx);
return;
}
r = r->next;
}
}
/* Register a callback receiver for cluster messages of type 'type'. If there
* was already a registered callback, this will replace the callback function
* with the one provided, otherwise if the callback is set to NULL and there
* is already a callback for this function, the callback is unregistered
* (so this API call is also used in order to delete the receiver). */
void RM_RegisterClusterMessageReceiver(RedisModuleCtx *ctx, uint8_t type, RedisModuleClusterMessageReceiver callback) {
if (!server.cluster_enabled) return;
uint64_t module_id = moduleTypeEncodeId(ctx->module->name,0);
moduleClusterReceiver *r = clusterReceivers[type], *prev = NULL;
while(r) {
if (r->module_id == module_id) {
/* Found! Set or delete. */
if (callback) {
r->callback = callback;
} else {
/* Delete the receiver entry if the user is setting
* it to NULL. Just unlink the receiver node from the
* linked list. */
if (prev)
prev->next = r->next;
else
clusterReceivers[type]->next = r->next;
zfree(r);
}
return;
}
prev = r;
r = r->next;
}
/* Not found, let's add it. */
if (callback) {
r = zmalloc(sizeof(*r));
r->module_id = module_id;
r->module = ctx->module;
r->callback = callback;
r->next = clusterReceivers[type];
clusterReceivers[type] = r;
}
}
/* Send a message to all the nodes in the cluster if `target` is NULL, otherwise
* at the specified target, which is a REDISMODULE_NODE_ID_LEN bytes node ID, as
* returned by the receiver callback or by the nodes iteration functions.
*
* The function returns REDISMODULE_OK if the message was successfully sent,
* otherwise if the node is not connected or such node ID does not map to any
* known cluster node, REDISMODULE_ERR is returned. */
int RM_SendClusterMessage(RedisModuleCtx *ctx, char *target_id, uint8_t type, unsigned char *msg, uint32_t len) {
if (!server.cluster_enabled) return REDISMODULE_ERR;
uint64_t module_id = moduleTypeEncodeId(ctx->module->name,0);
if (clusterSendModuleMessageToTarget(target_id,module_id,type,msg,len) == C_OK)
return REDISMODULE_OK;
else
return REDISMODULE_ERR;
}
/* Return an array of string pointers, each string pointer points to a cluster
* node ID of exactly REDISMODULE_NODE_ID_SIZE bytes (without any null term).
* The number of returned node IDs is stored into `*numnodes`.
* However if this function is called by a module not running an a Redis
* instance with Redis Cluster enabled, NULL is returned instead.
*
* The IDs returned can be used with RedisModule_GetClusterNodeInfo() in order
* to get more information about single nodes.
*
* The array returned by this function must be freed using the function
* RedisModule_FreeClusterNodesList().
*
* Example:
*
* size_t count, j;
* char **ids = RedisModule_GetClusterNodesList(ctx,&count);
* for (j = 0; j < count; j++) {
* RedisModule_Log("notice","Node %.*s",
* REDISMODULE_NODE_ID_LEN,ids[j]);
* }
* RedisModule_FreeClusterNodesList(ids);
*/
char **RM_GetClusterNodesList(RedisModuleCtx *ctx, size_t *numnodes) {
UNUSED(ctx);
if (!server.cluster_enabled) return NULL;
size_t count = dictSize(server.cluster->nodes);
char **ids = zmalloc((count+1)*REDISMODULE_NODE_ID_LEN);
dictIterator *di = dictGetIterator(server.cluster->nodes);
dictEntry *de;
int j = 0;
while((de = dictNext(di)) != NULL) {
clusterNode *node = dictGetVal(de);
if (node->flags & (CLUSTER_NODE_NOADDR|CLUSTER_NODE_HANDSHAKE)) continue;
ids[j] = zmalloc(REDISMODULE_NODE_ID_LEN);
memcpy(ids[j],node->name,REDISMODULE_NODE_ID_LEN);
j++;
}
*numnodes = j;
ids[j] = NULL; /* Null term so that FreeClusterNodesList does not need
* to also get the count argument. */
dictReleaseIterator(di);
return ids;
}
/* Free the node list obtained with RedisModule_GetClusterNodesList. */
void RM_FreeClusterNodesList(char **ids) {
if (ids == NULL) return;
for (int j = 0; ids[j]; j++) zfree(ids[j]);
zfree(ids);
}
/* Return this node ID (REDISMODULE_CLUSTER_ID_LEN bytes) or NULL if the cluster
* is disabled. */
const char *RM_GetMyClusterID(void) {
if (!server.cluster_enabled) return NULL;
return server.cluster->myself->name;
}
/* Return the number of nodes in the cluster, regardless of their state
* (handshake, noaddress, ...) so that the number of active nodes may actually
* be smaller, but not greater than this number. If the instance is not in
* cluster mode, zero is returned. */
size_t RM_GetClusterSize(void) {
if (!server.cluster_enabled) return 0;
return dictSize(server.cluster->nodes);
}
/* Populate the specified info for the node having as ID the specified 'id',
* then returns REDISMODULE_OK. Otherwise if the node ID does not exist from
* the POV of this local node, REDISMODULE_ERR is returned.
*
* The arguments ip, master_id, port and flags can be NULL in case we don't
* need to populate back certain info. If an ip and master_id (only populated
* if the instance is a slave) are specified, they point to buffers holding
* at least REDISMODULE_NODE_ID_LEN bytes. The strings written back as ip
* and master_id are not null terminated.
*
* The list of flags reported is the following:
*
* * REDISMODULE_NODE_MYSELF This node
* * REDISMODULE_NODE_MASTER The node is a master
* * REDISMODULE_NODE_SLAVE The node is a replica
* * REDISMODULE_NODE_PFAIL We see the node as failing
* * REDISMODULE_NODE_FAIL The cluster agrees the node is failing
* * REDISMODULE_NODE_NOFAILOVER The slave is configured to never failover
*/
clusterNode *clusterLookupNode(const char *name); /* We need access to internals */
int RM_GetClusterNodeInfo(RedisModuleCtx *ctx, const char *id, char *ip, char *master_id, int *port, int *flags) {
UNUSED(ctx);
clusterNode *node = clusterLookupNode(id);
if (node == NULL ||
node->flags & (CLUSTER_NODE_NOADDR|CLUSTER_NODE_HANDSHAKE))
{
return REDISMODULE_ERR;
}
if (ip) strncpy(ip,node->ip,NET_IP_STR_LEN);
if (master_id) {
/* If the information is not available, the function will set the
* field to zero bytes, so that when the field can't be populated the
* function kinda remains predictable. */
if (node->flags & CLUSTER_NODE_MASTER && node->slaveof)
memcpy(master_id,node->slaveof->name,REDISMODULE_NODE_ID_LEN);
else
memset(master_id,0,REDISMODULE_NODE_ID_LEN);
}
if (port) *port = node->port;
/* As usually we have to remap flags for modules, in order to ensure
* we can provide binary compatibility. */
if (flags) {
*flags = 0;
if (node->flags & CLUSTER_NODE_MYSELF) *flags |= REDISMODULE_NODE_MYSELF;
if (node->flags & CLUSTER_NODE_MASTER) *flags |= REDISMODULE_NODE_MASTER;
if (node->flags & CLUSTER_NODE_SLAVE) *flags |= REDISMODULE_NODE_SLAVE;
if (node->flags & CLUSTER_NODE_PFAIL) *flags |= REDISMODULE_NODE_PFAIL;
if (node->flags & CLUSTER_NODE_FAIL) *flags |= REDISMODULE_NODE_FAIL;
if (node->flags & CLUSTER_NODE_NOFAILOVER) *flags |= REDISMODULE_NODE_NOFAILOVER;
}
return REDISMODULE_OK;
}
/* Set Redis Cluster flags in order to change the normal behavior of
* Redis Cluster, especially with the goal of disabling certain functions.
* This is useful for modules that use the Cluster API in order to create
* a different distributed system, but still want to use the Redis Cluster
* message bus. Flags that can be set:
*
* CLUSTER_MODULE_FLAG_NO_FAILOVER
* CLUSTER_MODULE_FLAG_NO_REDIRECTION
*
* With the following effects:
*
* NO_FAILOVER: prevent Redis Cluster slaves to failover a failing master.
* Also disables the replica migration feature.
*
* NO_REDIRECTION: Every node will accept any key, without trying to perform
* partitioning according to the user Redis Cluster algorithm.
* Slots informations will still be propagated across the
* cluster, but without effects. */
void RM_SetClusterFlags(RedisModuleCtx *ctx, uint64_t flags) {
UNUSED(ctx);
if (flags & REDISMODULE_CLUSTER_FLAG_NO_FAILOVER)
server.cluster_module_flags |= CLUSTER_MODULE_FLAG_NO_FAILOVER;
if (flags & REDISMODULE_CLUSTER_FLAG_NO_REDIRECTION)
server.cluster_module_flags |= CLUSTER_MODULE_FLAG_NO_REDIRECTION;
}
/* --------------------------------------------------------------------------
* Modules Timers API
*
* Module timers are an high precision "green timers" abstraction where
* every module can register even millions of timers without problems, even if
* the actual event loop will just have a single timer that is used to awake the
* module timers subsystem in order to process the next event.
*
* All the timers are stored into a radix tree, ordered by expire time, when
* the main Redis event loop timer callback is called, we try to process all
* the timers already expired one after the other. Then we re-enter the event
* loop registering a timer that will expire when the next to process module
* timer will expire.
*
* Every time the list of active timers drops to zero, we unregister the
* main event loop timer, so that there is no overhead when such feature is
* not used.
* -------------------------------------------------------------------------- */
static rax *Timers; /* The radix tree of all the timers sorted by expire. */
long long aeTimer = -1; /* Main event loop (ae.c) timer identifier. */
typedef void (*RedisModuleTimerProc)(RedisModuleCtx *ctx, void *data);
/* The timer descriptor, stored as value in the radix tree. */
typedef struct RedisModuleTimer {
RedisModule *module; /* Module reference. */
RedisModuleTimerProc callback; /* The callback to invoke on expire. */
void *data; /* Private data for the callback. */
int dbid; /* Database number selected by the original client. */
} RedisModuleTimer;
/* This is the timer handler that is called by the main event loop. We schedule
* this timer to be called when the nearest of our module timers will expire. */
int moduleTimerHandler(struct aeEventLoop *eventLoop, long long id, void *clientData) {
UNUSED(eventLoop);
UNUSED(id);
UNUSED(clientData);
/* To start let's try to fire all the timers already expired. */
raxIterator ri;
raxStart(&ri,Timers);
uint64_t now = ustime();
long long next_period = 0;
while(1) {
raxSeek(&ri,"^",NULL,0);
if (!raxNext(&ri)) break;
uint64_t expiretime;
memcpy(&expiretime,ri.key,sizeof(expiretime));
expiretime = ntohu64(expiretime);
if (now >= expiretime) {
RedisModuleTimer *timer = ri.data;
RedisModuleCtx ctx = REDISMODULE_CTX_INIT;
ctx.module = timer->module;
ctx.client = moduleFreeContextReusedClient;
selectDb(ctx.client, timer->dbid);
timer->callback(&ctx,timer->data);
moduleFreeContext(&ctx);
raxRemove(Timers,(unsigned char*)ri.key,ri.key_len,NULL);
zfree(timer);
} else {
next_period = (expiretime-now)/1000; /* Scale to milliseconds. */
break;
}
}
raxStop(&ri);
/* Reschedule the next timer or cancel it. */
if (next_period <= 0) next_period = 1;
return (raxSize(Timers) > 0) ? next_period : AE_NOMORE;
}
/* Create a new timer that will fire after `period` milliseconds, and will call
* the specified function using `data` as argument. The returned timer ID can be
* used to get information from the timer or to stop it before it fires. */
RedisModuleTimerID RM_CreateTimer(RedisModuleCtx *ctx, mstime_t period, RedisModuleTimerProc callback, void *data) {
RedisModuleTimer *timer = zmalloc(sizeof(*timer));
timer->module = ctx->module;
timer->callback = callback;
timer->data = data;
timer->dbid = ctx->client ? ctx->client->db->id : 0;
uint64_t expiretime = ustime()+period*1000;
uint64_t key;
while(1) {
key = htonu64(expiretime);
if (raxFind(Timers, (unsigned char*)&key,sizeof(key)) == raxNotFound) {
raxInsert(Timers,(unsigned char*)&key,sizeof(key),timer,NULL);
break;
} else {
expiretime++;
}
}
/* We need to install the main event loop timer if it's not already
* installed, or we may need to refresh its period if we just installed
* a timer that will expire sooner than any other else. */
if (aeTimer != -1) {
raxIterator ri;
raxStart(&ri,Timers);
raxSeek(&ri,"^",NULL,0);
raxNext(&ri);
if (memcmp(ri.key,&key,sizeof(key)) == 0) {
/* This is the first key, we need to re-install the timer according
* to the just added event. */
aeDeleteTimeEvent(server.el,aeTimer);
aeTimer = -1;
}
raxStop(&ri);
}
/* If we have no main timer (the old one was invalidated, or this is the
* first module timer we have), install one. */
if (aeTimer == -1)
aeTimer = aeCreateTimeEvent(server.el,period,moduleTimerHandler,NULL,NULL);
return key;
}
/* Stop a timer, returns REDISMODULE_OK if the timer was found, belonged to the
* calling module, and was stopped, otherwise REDISMODULE_ERR is returned.
* If not NULL, the data pointer is set to the value of the data argument when
* the timer was created. */
int RM_StopTimer(RedisModuleCtx *ctx, RedisModuleTimerID id, void **data) {
RedisModuleTimer *timer = raxFind(Timers,(unsigned char*)&id,sizeof(id));
if (timer == raxNotFound || timer->module != ctx->module)
return REDISMODULE_ERR;
if (data) *data = timer->data;
raxRemove(Timers,(unsigned char*)&id,sizeof(id),NULL);
zfree(timer);
return REDISMODULE_OK;
}
/* Obtain information about a timer: its remaining time before firing
* (in milliseconds), and the private data pointer associated with the timer.
* If the timer specified does not exist or belongs to a different module
* no information is returned and the function returns REDISMODULE_ERR, otherwise
* REDISMODULE_OK is returned. The arguments remaining or data can be NULL if
* the caller does not need certain information. */
int RM_GetTimerInfo(RedisModuleCtx *ctx, RedisModuleTimerID id, uint64_t *remaining, void **data) {
RedisModuleTimer *timer = raxFind(Timers,(unsigned char*)&id,sizeof(id));
if (timer == raxNotFound || timer->module != ctx->module)
return REDISMODULE_ERR;
if (remaining) {
int64_t rem = ntohu64(id)-ustime();
if (rem < 0) rem = 0;
*remaining = rem/1000; /* Scale to milliseconds. */
}
if (data) *data = timer->data;
return REDISMODULE_OK;
}
/* --------------------------------------------------------------------------
* Modules ACL API
*
* Implements a hook into the authentication and authorization within Redis.
* --------------------------------------------------------------------------*/
/* This function is called when a client's user has changed and invokes the
* client's user changed callback if it was set. This callback should
* cleanup any state the module was tracking about this client.
*
* A client's user can be changed through the AUTH command, module
* authentication, and when a client is freed. */
void moduleNotifyUserChanged(client *c) {
if (c->auth_callback) {
c->auth_callback(c->id, c->auth_callback_privdata);
/* The callback will fire exactly once, even if the user remains
* the same. It is expected to completely clean up the state
* so all references are cleared here. */
c->auth_callback = NULL;
c->auth_callback_privdata = NULL;
c->auth_module = NULL;
}
}
void revokeClientAuthentication(client *c) {
/* Freeing the client would result in moduleNotifyUserChanged() to be
* called later, however since we use revokeClientAuthentication() also
* in moduleFreeAuthenticatedClients() to implement module unloading, we
* do this action ASAP: this way if the module is unloaded, when the client
* is eventually freed we don't rely on the module to still exist. */
moduleNotifyUserChanged(c);
c->user = DefaultUser;
c->authenticated = 0;
/* We will write replies to this client later, so we can't close it
* directly even if async. */
if (c == server.current_client) {
c->flags |= CLIENT_CLOSE_AFTER_COMMAND;
} else {
freeClientAsync(c);
}
}
/* Cleanup all clients that have been authenticated with this module. This
* is called from onUnload() to give the module a chance to cleanup any
* resources associated with clients it has authenticated. */
static void moduleFreeAuthenticatedClients(RedisModule *module) {
listIter li;
listNode *ln;
listRewind(server.clients,&li);
while ((ln = listNext(&li)) != NULL) {
client *c = listNodeValue(ln);
if (!c->auth_module) continue;
RedisModule *auth_module = (RedisModule *) c->auth_module;
if (auth_module == module) {
revokeClientAuthentication(c);
}
}
}
/* Creates a Redis ACL user that the module can use to authenticate a client.
* After obtaining the user, the module should set what such user can do
* using the RM_SetUserACL() function. Once configured, the user
* can be used in order to authenticate a connection, with the specified
* ACL rules, using the RedisModule_AuthClientWithUser() function.
*
* Note that:
*
* * Users created here are not listed by the ACL command.
* * Users created here are not checked for duplicated name, so it's up to
* the module calling this function to take care of not creating users
* with the same name.
* * The created user can be used to authenticate multiple Redis connections.
*
* The caller can later free the user using the function
* RM_FreeModuleUser(). When this function is called, if there are
* still clients authenticated with this user, they are disconnected.
* The function to free the user should only be used when the caller really
* wants to invalidate the user to define a new one with different
* capabilities. */
RedisModuleUser *RM_CreateModuleUser(const char *name) {
RedisModuleUser *new_user = zmalloc(sizeof(RedisModuleUser));
new_user->user = ACLCreateUnlinkedUser();
/* Free the previous temporarily assigned name to assign the new one */
sdsfree(new_user->user->name);
new_user->user->name = sdsnew(name);
return new_user;
}
/* Frees a given user and disconnects all of the clients that have been
* authenticated with it. See RM_CreateModuleUser for detailed usage.*/
int RM_FreeModuleUser(RedisModuleUser *user) {
ACLFreeUserAndKillClients(user->user);
zfree(user);
return REDISMODULE_OK;
}
/* Sets the permissions of a user created through the redis module
* interface. The syntax is the same as ACL SETUSER, so refer to the
* documentation in acl.c for more information. See RM_CreateModuleUser
* for detailed usage.
*
* Returns REDISMODULE_OK on success and REDISMODULE_ERR on failure
* and will set an errno describing why the operation failed. */
int RM_SetModuleUserACL(RedisModuleUser *user, const char* acl) {
return ACLSetUser(user->user, acl, -1);
}
/* Authenticate the client associated with the context with
* the provided user. Returns REDISMODULE_OK on success and
* REDISMODULE_ERR on error.
*
* This authentication can be tracked with the optional callback and private
* data fields. The callback will be called whenever the user of the client
* changes. This callback should be used to cleanup any state that is being
* kept in the module related to the client authentication. It will only be
* called once, even when the user hasn't changed, in order to allow for a
* new callback to be specified. If this authentication does not need to be
* tracked, pass in NULL for the callback and privdata.
*
* If client_id is not NULL, it will be filled with the id of the client
* that was authenticated. This can be used with the
* RM_DeauthenticateAndCloseClient() API in order to deauthenticate a
* previously authenticated client if the authentication is no longer valid.
*
* For expensive authentication operations, it is recommended to block the
* client and do the authentication in the background and then attach the user
* to the client in a threadsafe context. */
static int authenticateClientWithUser(RedisModuleCtx *ctx, user *user, RedisModuleUserChangedFunc callback, void *privdata, uint64_t *client_id) {
if (user->flags & USER_FLAG_DISABLED) {
return REDISMODULE_ERR;
}
/* Avoid settings which are meaningless and will be lost */
if (!ctx->client || (ctx->client->flags & CLIENT_MODULE)) {
return REDISMODULE_ERR;
}
moduleNotifyUserChanged(ctx->client);
ctx->client->user = user;
ctx->client->authenticated = 1;
if (callback) {
ctx->client->auth_callback = callback;
ctx->client->auth_callback_privdata = privdata;
ctx->client->auth_module = ctx->module;
}
if (client_id) {
*client_id = ctx->client->id;
}
return REDISMODULE_OK;
}
/* Authenticate the current context's user with the provided redis acl user.
* Returns REDISMODULE_ERR if the user is disabled.
*
* See authenticateClientWithUser for information about callback, client_id,
* and general usage for authentication. */
int RM_AuthenticateClientWithUser(RedisModuleCtx *ctx, RedisModuleUser *module_user, RedisModuleUserChangedFunc callback, void *privdata, uint64_t *client_id) {
return authenticateClientWithUser(ctx, module_user->user, callback, privdata, client_id);
}
/* Authenticate the current context's user with the provided redis acl user.
* Returns REDISMODULE_ERR if the user is disabled or the user does not exist.
*
* See authenticateClientWithUser for information about callback, client_id,
* and general usage for authentication. */
int RM_AuthenticateClientWithACLUser(RedisModuleCtx *ctx, const char *name, size_t len, RedisModuleUserChangedFunc callback, void *privdata, uint64_t *client_id) {
user *acl_user = ACLGetUserByName(name, len);
if (!acl_user) {
return REDISMODULE_ERR;
}
return authenticateClientWithUser(ctx, acl_user, callback, privdata, client_id);
}
/* Deauthenticate and close the client. The client resources will not be
* be immediately freed, but will be cleaned up in a background job. This is
* the recommended way to deauthenicate a client since most clients can't
* handle users becoming deauthenticated. Returns REDISMODULE_ERR when the
* client doesn't exist and REDISMODULE_OK when the operation was successful.
*
* The client ID is returned from the RM_AuthenticateClientWithUser and
* RM_AuthenticateClientWithACLUser APIs, but can be obtained through
* the CLIENT api or through server events.
*
* This function is not thread safe, and must be executed within the context
* of a command or thread safe context. */
int RM_DeauthenticateAndCloseClient(RedisModuleCtx *ctx, uint64_t client_id) {
UNUSED(ctx);
client *c = lookupClientByID(client_id);
if (c == NULL) return REDISMODULE_ERR;
/* Revoke also marks client to be closed ASAP */
revokeClientAuthentication(c);
return REDISMODULE_OK;
}
/* --------------------------------------------------------------------------
* Modules Dictionary API
*
* Implements a sorted dictionary (actually backed by a radix tree) with
* the usual get / set / del / num-items API, together with an iterator
* capable of going back and forth.
* -------------------------------------------------------------------------- */
/* Create a new dictionary. The 'ctx' pointer can be the current module context
* or NULL, depending on what you want. Please follow the following rules:
*
* 1. Use a NULL context if you plan to retain a reference to this dictionary
* that will survive the time of the module callback where you created it.
* 2. Use a NULL context if no context is available at the time you are creating
* the dictionary (of course...).
* 3. However use the current callback context as 'ctx' argument if the
* dictionary time to live is just limited to the callback scope. In this
* case, if enabled, you can enjoy the automatic memory management that will
* reclaim the dictionary memory, as well as the strings returned by the
* Next / Prev dictionary iterator calls.
*/
RedisModuleDict *RM_CreateDict(RedisModuleCtx *ctx) {
struct RedisModuleDict *d = zmalloc(sizeof(*d));
d->rax = raxNew();
if (ctx != NULL) autoMemoryAdd(ctx,REDISMODULE_AM_DICT,d);
return d;
}
/* Free a dictionary created with RM_CreateDict(). You need to pass the
* context pointer 'ctx' only if the dictionary was created using the
* context instead of passing NULL. */
void RM_FreeDict(RedisModuleCtx *ctx, RedisModuleDict *d) {
if (ctx != NULL) autoMemoryFreed(ctx,REDISMODULE_AM_DICT,d);
raxFree(d->rax);
zfree(d);
}
/* Return the size of the dictionary (number of keys). */
uint64_t RM_DictSize(RedisModuleDict *d) {
return raxSize(d->rax);
}
/* Store the specified key into the dictionary, setting its value to the
* pointer 'ptr'. If the key was added with success, since it did not
* already exist, REDISMODULE_OK is returned. Otherwise if the key already
* exists the function returns REDISMODULE_ERR. */
int RM_DictSetC(RedisModuleDict *d, void *key, size_t keylen, void *ptr) {
int retval = raxTryInsert(d->rax,key,keylen,ptr,NULL);
return (retval == 1) ? REDISMODULE_OK : REDISMODULE_ERR;
}
/* Like RedisModule_DictSetC() but will replace the key with the new
* value if the key already exists. */
int RM_DictReplaceC(RedisModuleDict *d, void *key, size_t keylen, void *ptr) {
int retval = raxInsert(d->rax,key,keylen,ptr,NULL);
return (retval == 1) ? REDISMODULE_OK : REDISMODULE_ERR;
}
/* Like RedisModule_DictSetC() but takes the key as a RedisModuleString. */
int RM_DictSet(RedisModuleDict *d, RedisModuleString *key, void *ptr) {
return RM_DictSetC(d,key->ptr,sdslen(key->ptr),ptr);
}
/* Like RedisModule_DictReplaceC() but takes the key as a RedisModuleString. */
int RM_DictReplace(RedisModuleDict *d, RedisModuleString *key, void *ptr) {
return RM_DictReplaceC(d,key->ptr,sdslen(key->ptr),ptr);
}
/* Return the value stored at the specified key. The function returns NULL
* both in the case the key does not exist, or if you actually stored
* NULL at key. So, optionally, if the 'nokey' pointer is not NULL, it will
* be set by reference to 1 if the key does not exist, or to 0 if the key
* exists. */
void *RM_DictGetC(RedisModuleDict *d, void *key, size_t keylen, int *nokey) {
void *res = raxFind(d->rax,key,keylen);
if (nokey) *nokey = (res == raxNotFound);
return (res == raxNotFound) ? NULL : res;
}
/* Like RedisModule_DictGetC() but takes the key as a RedisModuleString. */
void *RM_DictGet(RedisModuleDict *d, RedisModuleString *key, int *nokey) {
return RM_DictGetC(d,key->ptr,sdslen(key->ptr),nokey);
}
/* Remove the specified key from the dictionary, returning REDISMODULE_OK if
* the key was found and delted, or REDISMODULE_ERR if instead there was
* no such key in the dictionary. When the operation is successful, if
* 'oldval' is not NULL, then '*oldval' is set to the value stored at the
* key before it was deleted. Using this feature it is possible to get
* a pointer to the value (for instance in order to release it), without
* having to call RedisModule_DictGet() before deleting the key. */
int RM_DictDelC(RedisModuleDict *d, void *key, size_t keylen, void *oldval) {
int retval = raxRemove(d->rax,key,keylen,oldval);
return retval ? REDISMODULE_OK : REDISMODULE_ERR;
}
/* Like RedisModule_DictDelC() but gets the key as a RedisModuleString. */
int RM_DictDel(RedisModuleDict *d, RedisModuleString *key, void *oldval) {
return RM_DictDelC(d,key->ptr,sdslen(key->ptr),oldval);
}
/* Return an iterator, setup in order to start iterating from the specified
* key by applying the operator 'op', which is just a string specifying the
* comparison operator to use in order to seek the first element. The
* operators available are:
*
* "^" -- Seek the first (lexicographically smaller) key.
* "$" -- Seek the last (lexicographically biffer) key.
* ">" -- Seek the first element greater than the specified key.
* ">=" -- Seek the first element greater or equal than the specified key.
* "<" -- Seek the first element smaller than the specified key.
* "<=" -- Seek the first element smaller or equal than the specified key.
* "==" -- Seek the first element matching exactly the specified key.
*
* Note that for "^" and "$" the passed key is not used, and the user may
* just pass NULL with a length of 0.
*
* If the element to start the iteration cannot be seeked based on the
* key and operator passed, RedisModule_DictNext() / Prev() will just return
* REDISMODULE_ERR at the first call, otherwise they'll produce elements.
*/
RedisModuleDictIter *RM_DictIteratorStartC(RedisModuleDict *d, const char *op, void *key, size_t keylen) {
RedisModuleDictIter *di = zmalloc(sizeof(*di));
di->dict = d;
raxStart(&di->ri,d->rax);
raxSeek(&di->ri,op,key,keylen);
return di;
}
/* Exactly like RedisModule_DictIteratorStartC, but the key is passed as a
* RedisModuleString. */
RedisModuleDictIter *RM_DictIteratorStart(RedisModuleDict *d, const char *op, RedisModuleString *key) {
return RM_DictIteratorStartC(d,op,key->ptr,sdslen(key->ptr));
}
/* Release the iterator created with RedisModule_DictIteratorStart(). This call
* is mandatory otherwise a memory leak is introduced in the module. */
void RM_DictIteratorStop(RedisModuleDictIter *di) {
raxStop(&di->ri);
zfree(di);
}
/* After its creation with RedisModule_DictIteratorStart(), it is possible to
* change the currently selected element of the iterator by using this
* API call. The result based on the operator and key is exactly like
* the function RedisModule_DictIteratorStart(), however in this case the
* return value is just REDISMODULE_OK in case the seeked element was found,
* or REDISMODULE_ERR in case it was not possible to seek the specified
* element. It is possible to reseek an iterator as many times as you want. */
int RM_DictIteratorReseekC(RedisModuleDictIter *di, const char *op, void *key, size_t keylen) {
return raxSeek(&di->ri,op,key,keylen);
}
/* Like RedisModule_DictIteratorReseekC() but takes the key as as a
* RedisModuleString. */
int RM_DictIteratorReseek(RedisModuleDictIter *di, const char *op, RedisModuleString *key) {
return RM_DictIteratorReseekC(di,op,key->ptr,sdslen(key->ptr));
}
/* Return the current item of the dictionary iterator 'di' and steps to the
* next element. If the iterator already yield the last element and there
* are no other elements to return, NULL is returned, otherwise a pointer
* to a string representing the key is provided, and the '*keylen' length
* is set by reference (if keylen is not NULL). The '*dataptr', if not NULL
* is set to the value of the pointer stored at the returned key as auxiliary
* data (as set by the RedisModule_DictSet API).
*
* Usage example:
*
* ... create the iterator here ...
* char *key;
* void *data;
* while((key = RedisModule_DictNextC(iter,&keylen,&data)) != NULL) {
* printf("%.*s %p\n", (int)keylen, key, data);
* }
*
* The returned pointer is of type void because sometimes it makes sense
* to cast it to a char* sometimes to an unsigned char* depending on the
* fact it contains or not binary data, so this API ends being more
* comfortable to use.
*
* The validity of the returned pointer is until the next call to the
* next/prev iterator step. Also the pointer is no longer valid once the
* iterator is released. */
void *RM_DictNextC(RedisModuleDictIter *di, size_t *keylen, void **dataptr) {
if (!raxNext(&di->ri)) return NULL;
if (keylen) *keylen = di->ri.key_len;
if (dataptr) *dataptr = di->ri.data;
return di->ri.key;
}
/* This function is exactly like RedisModule_DictNext() but after returning
* the currently selected element in the iterator, it selects the previous
* element (laxicographically smaller) instead of the next one. */
void *RM_DictPrevC(RedisModuleDictIter *di, size_t *keylen, void **dataptr) {
if (!raxPrev(&di->ri)) return NULL;
if (keylen) *keylen = di->ri.key_len;
if (dataptr) *dataptr = di->ri.data;
return di->ri.key;
}
/* Like RedisModuleNextC(), but instead of returning an internally allocated
* buffer and key length, it returns directly a module string object allocated
* in the specified context 'ctx' (that may be NULL exactly like for the main
* API RedisModule_CreateString).
*
* The returned string object should be deallocated after use, either manually
* or by using a context that has automatic memory management active. */
RedisModuleString *RM_DictNext(RedisModuleCtx *ctx, RedisModuleDictIter *di, void **dataptr) {
size_t keylen;
void *key = RM_DictNextC(di,&keylen,dataptr);
if (key == NULL) return NULL;
return RM_CreateString(ctx,key,keylen);
}
/* Like RedisModule_DictNext() but after returning the currently selected
* element in the iterator, it selects the previous element (laxicographically
* smaller) instead of the next one. */
RedisModuleString *RM_DictPrev(RedisModuleCtx *ctx, RedisModuleDictIter *di, void **dataptr) {
size_t keylen;
void *key = RM_DictPrevC(di,&keylen,dataptr);
if (key == NULL) return NULL;
return RM_CreateString(ctx,key,keylen);
}
/* Compare the element currently pointed by the iterator to the specified
* element given by key/keylen, according to the operator 'op' (the set of
* valid operators are the same valid for RedisModule_DictIteratorStart).
* If the comparision is successful the command returns REDISMODULE_OK
* otherwise REDISMODULE_ERR is returned.
*
* This is useful when we want to just emit a lexicographical range, so
* in the loop, as we iterate elements, we can also check if we are still
* on range.
*
* The function return REDISMODULE_ERR if the iterator reached the
* end of elements condition as well. */
int RM_DictCompareC(RedisModuleDictIter *di, const char *op, void *key, size_t keylen) {
if (raxEOF(&di->ri)) return REDISMODULE_ERR;
int res = raxCompare(&di->ri,op,key,keylen);
return res ? REDISMODULE_OK : REDISMODULE_ERR;
}
/* Like RedisModule_DictCompareC but gets the key to compare with the current
* iterator key as a RedisModuleString. */
int RM_DictCompare(RedisModuleDictIter *di, const char *op, RedisModuleString *key) {
if (raxEOF(&di->ri)) return REDISMODULE_ERR;
int res = raxCompare(&di->ri,op,key->ptr,sdslen(key->ptr));
return res ? REDISMODULE_OK : REDISMODULE_ERR;
}
/* --------------------------------------------------------------------------
* Modules Info fields
* -------------------------------------------------------------------------- */
int RM_InfoEndDictField(RedisModuleInfoCtx *ctx);
/* Used to start a new section, before adding any fields. the section name will
* be prefixed by "<modulename>_" and must only include A-Z,a-z,0-9.
* NULL or empty string indicates the default section (only <modulename>) is used.
* When return value is REDISMODULE_ERR, the section should and will be skipped. */
int RM_InfoAddSection(RedisModuleInfoCtx *ctx, char *name) {
sds full_name = sdsdup(ctx->module->name);
if (name != NULL && strlen(name) > 0)
full_name = sdscatfmt(full_name, "_%s", name);
/* Implicitly end dicts, instead of returning an error which is likely un checked. */
if (ctx->in_dict_field)
RM_InfoEndDictField(ctx);
/* proceed only if:
* 1) no section was requested (emit all)
* 2) the module name was requested (emit all)
* 3) this specific section was requested. */
if (ctx->requested_section) {
if (strcasecmp(ctx->requested_section, full_name) &&
strcasecmp(ctx->requested_section, ctx->module->name)) {
sdsfree(full_name);
ctx->in_section = 0;
return REDISMODULE_ERR;
}
}
if (ctx->sections++) ctx->info = sdscat(ctx->info,"\r\n");
ctx->info = sdscatfmt(ctx->info, "# %S\r\n", full_name);
ctx->in_section = 1;
sdsfree(full_name);
return REDISMODULE_OK;
}
/* Starts a dict field, similar to the ones in INFO KEYSPACE. Use normal
* RedisModule_InfoAddField* functions to add the items to this field, and
* terminate with RedisModule_InfoEndDictField. */
int RM_InfoBeginDictField(RedisModuleInfoCtx *ctx, char *name) {
if (!ctx->in_section)
return REDISMODULE_ERR;
/* Implicitly end dicts, instead of returning an error which is likely un checked. */
if (ctx->in_dict_field)
RM_InfoEndDictField(ctx);
ctx->info = sdscatfmt(ctx->info,
"%s_%s:",
ctx->module->name,
name);
ctx->in_dict_field = 1;
return REDISMODULE_OK;
}
/* Ends a dict field, see RedisModule_InfoBeginDictField */
int RM_InfoEndDictField(RedisModuleInfoCtx *ctx) {
if (!ctx->in_dict_field)
return REDISMODULE_ERR;
/* trim the last ',' if found. */
if (ctx->info[sdslen(ctx->info)-1]==',')
sdsIncrLen(ctx->info, -1);
ctx->info = sdscat(ctx->info, "\r\n");
ctx->in_dict_field = 0;
return REDISMODULE_OK;
}
/* Used by RedisModuleInfoFunc to add info fields.
* Each field will be automatically prefixed by "<modulename>_".
* Field names or values must not include \r\n of ":" */
int RM_InfoAddFieldString(RedisModuleInfoCtx *ctx, char *field, RedisModuleString *value) {
if (!ctx->in_section)
return REDISMODULE_ERR;
if (ctx->in_dict_field) {
ctx->info = sdscatfmt(ctx->info,
"%s=%S,",
field,
(sds)value->ptr);
return REDISMODULE_OK;
}
ctx->info = sdscatfmt(ctx->info,
"%s_%s:%S\r\n",
ctx->module->name,
field,
(sds)value->ptr);
return REDISMODULE_OK;
}
int RM_InfoAddFieldCString(RedisModuleInfoCtx *ctx, char *field, char *value) {
if (!ctx->in_section)
return REDISMODULE_ERR;
if (ctx->in_dict_field) {
ctx->info = sdscatfmt(ctx->info,
"%s=%s,",
field,
value);
return REDISMODULE_OK;
}
ctx->info = sdscatfmt(ctx->info,
"%s_%s:%s\r\n",
ctx->module->name,
field,
value);
return REDISMODULE_OK;
}
int RM_InfoAddFieldDouble(RedisModuleInfoCtx *ctx, char *field, double value) {
if (!ctx->in_section)
return REDISMODULE_ERR;
if (ctx->in_dict_field) {
ctx->info = sdscatprintf(ctx->info,
"%s=%.17g,",
field,
value);
return REDISMODULE_OK;
}
ctx->info = sdscatprintf(ctx->info,
"%s_%s:%.17g\r\n",
ctx->module->name,
field,
value);
return REDISMODULE_OK;
}
int RM_InfoAddFieldLongLong(RedisModuleInfoCtx *ctx, char *field, long long value) {
if (!ctx->in_section)
return REDISMODULE_ERR;
if (ctx->in_dict_field) {
ctx->info = sdscatfmt(ctx->info,
"%s=%I,",
field,
value);
return REDISMODULE_OK;
}
ctx->info = sdscatfmt(ctx->info,
"%s_%s:%I\r\n",
ctx->module->name,
field,
value);
return REDISMODULE_OK;
}
int RM_InfoAddFieldULongLong(RedisModuleInfoCtx *ctx, char *field, unsigned long long value) {
if (!ctx->in_section)
return REDISMODULE_ERR;
if (ctx->in_dict_field) {
ctx->info = sdscatfmt(ctx->info,
"%s=%U,",
field,
value);
return REDISMODULE_OK;
}
ctx->info = sdscatfmt(ctx->info,
"%s_%s:%U\r\n",
ctx->module->name,
field,
value);
return REDISMODULE_OK;
}
int RM_RegisterInfoFunc(RedisModuleCtx *ctx, RedisModuleInfoFunc cb) {
ctx->module->info_cb = cb;
return REDISMODULE_OK;
}
sds modulesCollectInfo(sds info, const char *section, int for_crash_report, int sections) {
dictIterator *di = dictGetIterator(modules);
dictEntry *de;
while ((de = dictNext(di)) != NULL) {
struct RedisModule *module = dictGetVal(de);
if (!module->info_cb)
continue;
RedisModuleInfoCtx info_ctx = {module, section, info, sections, 0, 0};
module->info_cb(&info_ctx, for_crash_report);
/* Implicitly end dicts (no way to handle errors, and we must add the newline). */
if (info_ctx.in_dict_field)
RM_InfoEndDictField(&info_ctx);
info = info_ctx.info;
sections = info_ctx.sections;
}
dictReleaseIterator(di);
return info;
}
/* Get information about the server similar to the one that returns from the
* INFO command. This function takes an optional 'section' argument that may
* be NULL. The return value holds the output and can be used with
* RedisModule_ServerInfoGetField and alike to get the individual fields.
* When done, it needs to be freed with RedisModule_FreeServerInfo or with the
* automatic memory management mechanism if enabled. */
RedisModuleServerInfoData *RM_GetServerInfo(RedisModuleCtx *ctx, const char *section) {
struct RedisModuleServerInfoData *d = zmalloc(sizeof(*d));
d->rax = raxNew();
if (ctx != NULL) autoMemoryAdd(ctx,REDISMODULE_AM_INFO,d);
sds info = genRedisInfoString(section);
int totlines, i;
sds *lines = sdssplitlen(info, sdslen(info), "\r\n", 2, &totlines);
for(i=0; i<totlines; i++) {
sds line = lines[i];
if (line[0]=='#') continue;
char *sep = strchr(line, ':');
if (!sep) continue;
unsigned char *key = (unsigned char*)line;
size_t keylen = (intptr_t)sep-(intptr_t)line;
sds val = sdsnewlen(sep+1,sdslen(line)-((intptr_t)sep-(intptr_t)line)-1);
if (!raxTryInsert(d->rax,key,keylen,val,NULL))
sdsfree(val);
}
sdsfree(info);
sdsfreesplitres(lines,totlines);
return d;
}
/* Free data created with RM_GetServerInfo(). You need to pass the
* context pointer 'ctx' only if the dictionary was created using the
* context instead of passing NULL. */
void RM_FreeServerInfo(RedisModuleCtx *ctx, RedisModuleServerInfoData *data) {
if (ctx != NULL) autoMemoryFreed(ctx,REDISMODULE_AM_INFO,data);
raxIterator ri;
raxStart(&ri,data->rax);
while(1) {
raxSeek(&ri,"^",NULL,0);
if (!raxNext(&ri)) break;
raxRemove(data->rax,(unsigned char*)ri.key,ri.key_len,NULL);
sdsfree(ri.data);
}
raxStop(&ri);
raxFree(data->rax);
zfree(data);
}
/* Get the value of a field from data collected with RM_GetServerInfo(). You
* need to pass the context pointer 'ctx' only if you want to use auto memory
* mechanism to release the returned string. Return value will be NULL if the
* field was not found. */
RedisModuleString *RM_ServerInfoGetField(RedisModuleCtx *ctx, RedisModuleServerInfoData *data, const char* field) {
sds val = raxFind(data->rax, (unsigned char *)field, strlen(field));
if (val == raxNotFound) return NULL;
RedisModuleString *o = createStringObject(val,sdslen(val));
if (ctx != NULL) autoMemoryAdd(ctx,REDISMODULE_AM_STRING,o);
return o;
}
/* Similar to RM_ServerInfoGetField, but returns a char* which should not be freed but the caller. */
const char *RM_ServerInfoGetFieldC(RedisModuleServerInfoData *data, const char* field) {
sds val = raxFind(data->rax, (unsigned char *)field, strlen(field));
if (val == raxNotFound) return NULL;
return val;
}
/* Get the value of a field from data collected with RM_GetServerInfo(). If the
* field is not found, or is not numerical or out of range, return value will be
* 0, and the optional out_err argument will be set to REDISMODULE_ERR. */
long long RM_ServerInfoGetFieldSigned(RedisModuleServerInfoData *data, const char* field, int *out_err) {
long long ll;
sds val = raxFind(data->rax, (unsigned char *)field, strlen(field));
if (val == raxNotFound) {
if (out_err) *out_err = REDISMODULE_ERR;
return 0;
}
if (!string2ll(val,sdslen(val),&ll)) {
if (out_err) *out_err = REDISMODULE_ERR;
return 0;
}
if (out_err) *out_err = REDISMODULE_OK;
return ll;
}
/* Get the value of a field from data collected with RM_GetServerInfo(). If the
* field is not found, or is not numerical or out of range, return value will be
* 0, and the optional out_err argument will be set to REDISMODULE_ERR. */
unsigned long long RM_ServerInfoGetFieldUnsigned(RedisModuleServerInfoData *data, const char* field, int *out_err) {
unsigned long long ll;
sds val = raxFind(data->rax, (unsigned char *)field, strlen(field));
if (val == raxNotFound) {
if (out_err) *out_err = REDISMODULE_ERR;
return 0;
}
if (!string2ull(val,&ll)) {
if (out_err) *out_err = REDISMODULE_ERR;
return 0;
}
if (out_err) *out_err = REDISMODULE_OK;
return ll;
}
/* Get the value of a field from data collected with RM_GetServerInfo(). If the
* field is not found, or is not a double, return value will be 0, and the
* optional out_err argument will be set to REDISMODULE_ERR. */
double RM_ServerInfoGetFieldDouble(RedisModuleServerInfoData *data, const char* field, int *out_err) {
double dbl;
sds val = raxFind(data->rax, (unsigned char *)field, strlen(field));
if (val == raxNotFound) {
if (out_err) *out_err = REDISMODULE_ERR;
return 0;
}
if (!string2d(val,sdslen(val),&dbl)) {
if (out_err) *out_err = REDISMODULE_ERR;
return 0;
}
if (out_err) *out_err = REDISMODULE_OK;
return dbl;
}
/* --------------------------------------------------------------------------
* Modules utility APIs
* -------------------------------------------------------------------------- */
/* Return random bytes using SHA1 in counter mode with a /dev/urandom
* initialized seed. This function is fast so can be used to generate
* many bytes without any effect on the operating system entropy pool.
* Currently this function is not thread safe. */
void RM_GetRandomBytes(unsigned char *dst, size_t len) {
getRandomBytes(dst,len);
}
/* Like RedisModule_GetRandomBytes() but instead of setting the string to
* random bytes the string is set to random characters in the in the
* hex charset [0-9a-f]. */
void RM_GetRandomHexChars(char *dst, size_t len) {
getRandomHexChars(dst,len);
}
/* --------------------------------------------------------------------------
* Modules API exporting / importing
* -------------------------------------------------------------------------- */
/* This function is called by a module in order to export some API with a
* given name. Other modules will be able to use this API by calling the
* symmetrical function RM_GetSharedAPI() and casting the return value to
* the right function pointer.
*
* The function will return REDISMODULE_OK if the name is not already taken,
* otherwise REDISMODULE_ERR will be returned and no operation will be
* performed.
*
* IMPORTANT: the apiname argument should be a string literal with static
* lifetime. The API relies on the fact that it will always be valid in
* the future. */
int RM_ExportSharedAPI(RedisModuleCtx *ctx, const char *apiname, void *func) {
RedisModuleSharedAPI *sapi = zmalloc(sizeof(*sapi));
sapi->module = ctx->module;
sapi->func = func;
if (dictAdd(server.sharedapi, (char*)apiname, sapi) != DICT_OK) {
zfree(sapi);
return REDISMODULE_ERR;
}
return REDISMODULE_OK;
}
/* Request an exported API pointer. The return value is just a void pointer
* that the caller of this function will be required to cast to the right
* function pointer, so this is a private contract between modules.
*
* If the requested API is not available then NULL is returned. Because
* modules can be loaded at different times with different order, this
* function calls should be put inside some module generic API registering
* step, that is called every time a module attempts to execute a
* command that requires external APIs: if some API cannot be resolved, the
* command should return an error.
*
* Here is an example:
*
* int ... myCommandImplementation() {
* if (getExternalAPIs() == 0) {
* reply with an error here if we cannot have the APIs
* }
* // Use the API:
* myFunctionPointer(foo);
* }
*
* And the function registerAPI() is:
*
* int getExternalAPIs(void) {
* static int api_loaded = 0;
* if (api_loaded != 0) return 1; // APIs already resolved.
*
* myFunctionPointer = RedisModule_GetOtherModuleAPI("...");
* if (myFunctionPointer == NULL) return 0;
*
* return 1;
* }
*/
void *RM_GetSharedAPI(RedisModuleCtx *ctx, const char *apiname) {
dictEntry *de = dictFind(server.sharedapi, apiname);
if (de == NULL) return NULL;
RedisModuleSharedAPI *sapi = dictGetVal(de);
if (listSearchKey(sapi->module->usedby,ctx->module) == NULL) {
listAddNodeTail(sapi->module->usedby,ctx->module);
listAddNodeTail(ctx->module->using,sapi->module);
}
return sapi->func;
}
/* Remove all the APIs registered by the specified module. Usually you
* want this when the module is going to be unloaded. This function
* assumes that's caller responsibility to make sure the APIs are not
* used by other modules.
*
* The number of unregistered APIs is returned. */
int moduleUnregisterSharedAPI(RedisModule *module) {
int count = 0;
dictIterator *di = dictGetSafeIterator(server.sharedapi);
dictEntry *de;
while ((de = dictNext(di)) != NULL) {
const char *apiname = dictGetKey(de);
RedisModuleSharedAPI *sapi = dictGetVal(de);
if (sapi->module == module) {
dictDelete(server.sharedapi,apiname);
zfree(sapi);
count++;
}
}
dictReleaseIterator(di);
return count;
}
/* Remove the specified module as an user of APIs of ever other module.
* This is usually called when a module is unloaded.
*
* Returns the number of modules this module was using APIs from. */
int moduleUnregisterUsedAPI(RedisModule *module) {
listIter li;
listNode *ln;
int count = 0;
listRewind(module->using,&li);
while((ln = listNext(&li))) {
RedisModule *used = ln->value;
listNode *ln = listSearchKey(used->usedby,module);
if (ln) {
listDelNode(used->usedby,ln);
count++;
}
}
return count;
}
/* Unregister all filters registered by a module.
* This is called when a module is being unloaded.
*
* Returns the number of filters unregistered. */
int moduleUnregisterFilters(RedisModule *module) {
listIter li;
listNode *ln;
int count = 0;
listRewind(module->filters,&li);
while((ln = listNext(&li))) {
RedisModuleCommandFilter *filter = ln->value;
listNode *ln = listSearchKey(moduleCommandFilters,filter);
if (ln) {
listDelNode(moduleCommandFilters,ln);
count++;
}
zfree(filter);
}
return count;
}
/* --------------------------------------------------------------------------
* Module Command Filter API
* -------------------------------------------------------------------------- */
/* Register a new command filter function.
*
* Command filtering makes it possible for modules to extend Redis by plugging
* into the execution flow of all commands.
*
* A registered filter gets called before Redis executes *any* command. This
* includes both core Redis commands and commands registered by any module. The
* filter applies in all execution paths including:
*
* 1. Invocation by a client.
* 2. Invocation through `RedisModule_Call()` by any module.
* 3. Invocation through Lua 'redis.call()`.
* 4. Replication of a command from a master.
*
* The filter executes in a special filter context, which is different and more
* limited than a RedisModuleCtx. Because the filter affects any command, it
* must be implemented in a very efficient way to reduce the performance impact
* on Redis. All Redis Module API calls that require a valid context (such as
* `RedisModule_Call()`, `RedisModule_OpenKey()`, etc.) are not supported in a
* filter context.
*
* The `RedisModuleCommandFilterCtx` can be used to inspect or modify the
* executed command and its arguments. As the filter executes before Redis
* begins processing the command, any change will affect the way the command is
* processed. For example, a module can override Redis commands this way:
*
* 1. Register a `MODULE.SET` command which implements an extended version of
* the Redis `SET` command.
* 2. Register a command filter which detects invocation of `SET` on a specific
* pattern of keys. Once detected, the filter will replace the first
* argument from `SET` to `MODULE.SET`.
* 3. When filter execution is complete, Redis considers the new command name
* and therefore executes the module's own command.
*
* Note that in the above use case, if `MODULE.SET` itself uses
* `RedisModule_Call()` the filter will be applied on that call as well. If
* that is not desired, the `REDISMODULE_CMDFILTER_NOSELF` flag can be set when
* registering the filter.
*
* The `REDISMODULE_CMDFILTER_NOSELF` flag prevents execution flows that
* originate from the module's own `RM_Call()` from reaching the filter. This
* flag is effective for all execution flows, including nested ones, as long as
* the execution begins from the module's command context or a thread-safe
* context that is associated with a blocking command.
*
* Detached thread-safe contexts are *not* associated with the module and cannot
* be protected by this flag.
*
* If multiple filters are registered (by the same or different modules), they
* are executed in the order of registration.
*/
RedisModuleCommandFilter *RM_RegisterCommandFilter(RedisModuleCtx *ctx, RedisModuleCommandFilterFunc callback, int flags) {
RedisModuleCommandFilter *filter = zmalloc(sizeof(*filter));
filter->module = ctx->module;
filter->callback = callback;
filter->flags = flags;
listAddNodeTail(moduleCommandFilters, filter);
listAddNodeTail(ctx->module->filters, filter);
return filter;
}
/* Unregister a command filter.
*/
int RM_UnregisterCommandFilter(RedisModuleCtx *ctx, RedisModuleCommandFilter *filter) {
listNode *ln;
/* A module can only remove its own filters */
if (filter->module != ctx->module) return REDISMODULE_ERR;
ln = listSearchKey(moduleCommandFilters,filter);
if (!ln) return REDISMODULE_ERR;
listDelNode(moduleCommandFilters,ln);
ln = listSearchKey(ctx->module->filters,filter);
if (!ln) return REDISMODULE_ERR; /* Shouldn't happen */
listDelNode(ctx->module->filters,ln);
zfree(filter);
return REDISMODULE_OK;
}
void moduleCallCommandFilters(client *c) {
if (listLength(moduleCommandFilters) == 0) return;
listIter li;
listNode *ln;
listRewind(moduleCommandFilters,&li);
RedisModuleCommandFilterCtx filter = {
.argv = c->argv,
.argc = c->argc
};
while((ln = listNext(&li))) {
RedisModuleCommandFilter *f = ln->value;
/* Skip filter if REDISMODULE_CMDFILTER_NOSELF is set and module is
* currently processing a command.
*/
if ((f->flags & REDISMODULE_CMDFILTER_NOSELF) && f->module->in_call) continue;
/* Call filter */
f->callback(&filter);
}
c->argv = filter.argv;
c->argc = filter.argc;
}
/* Return the number of arguments a filtered command has. The number of
* arguments include the command itself.
*/
int RM_CommandFilterArgsCount(RedisModuleCommandFilterCtx *fctx)
{
return fctx->argc;
}
/* Return the specified command argument. The first argument (position 0) is
* the command itself, and the rest are user-provided args.
*/
const RedisModuleString *RM_CommandFilterArgGet(RedisModuleCommandFilterCtx *fctx, int pos)
{
if (pos < 0 || pos >= fctx->argc) return NULL;
return fctx->argv[pos];
}
/* Modify the filtered command by inserting a new argument at the specified
* position. The specified RedisModuleString argument may be used by Redis
* after the filter context is destroyed, so it must not be auto-memory
* allocated, freed or used elsewhere.
*/
int RM_CommandFilterArgInsert(RedisModuleCommandFilterCtx *fctx, int pos, RedisModuleString *arg)
{
int i;
if (pos < 0 || pos > fctx->argc) return REDISMODULE_ERR;
fctx->argv = zrealloc(fctx->argv, (fctx->argc+1)*sizeof(RedisModuleString *));
for (i = fctx->argc; i > pos; i--) {
fctx->argv[i] = fctx->argv[i-1];
}
fctx->argv[pos] = arg;
fctx->argc++;
return REDISMODULE_OK;
}
/* Modify the filtered command by replacing an existing argument with a new one.
* The specified RedisModuleString argument may be used by Redis after the
* filter context is destroyed, so it must not be auto-memory allocated, freed
* or used elsewhere.
*/
int RM_CommandFilterArgReplace(RedisModuleCommandFilterCtx *fctx, int pos, RedisModuleString *arg)
{
if (pos < 0 || pos >= fctx->argc) return REDISMODULE_ERR;
decrRefCount(fctx->argv[pos]);
fctx->argv[pos] = arg;
return REDISMODULE_OK;
}
/* Modify the filtered command by deleting an argument at the specified
* position.
*/
int RM_CommandFilterArgDelete(RedisModuleCommandFilterCtx *fctx, int pos)
{
int i;
if (pos < 0 || pos >= fctx->argc) return REDISMODULE_ERR;
decrRefCount(fctx->argv[pos]);
for (i = pos; i < fctx->argc-1; i++) {
fctx->argv[i] = fctx->argv[i+1];
}
fctx->argc--;
return REDISMODULE_OK;
}
/* For a given pointer allocated via RedisModule_Alloc() or
* RedisModule_Realloc(), return the amount of memory allocated for it.
* Note that this may be different (larger) than the memory we allocated
* with the allocation calls, since sometimes the underlying allocator
* will allocate more memory.
*/
size_t RM_MallocSize(void* ptr){
return zmalloc_size(ptr);
}
/* Return the a number between 0 to 1 indicating the amount of memory
* currently used, relative to the Redis "maxmemory" configuration.
*
* 0 - No memory limit configured.
* Between 0 and 1 - The percentage of the memory used normalized in 0-1 range.
* Exactly 1 - Memory limit reached.
* Greater 1 - More memory used than the configured limit.
*/
float RM_GetUsedMemoryRatio(){
float level;
getMaxmemoryState(NULL, NULL, NULL, &level);
return level;
}
/* --------------------------------------------------------------------------
* Scanning keyspace and hashes
* -------------------------------------------------------------------------- */
typedef void (*RedisModuleScanCB)(RedisModuleCtx *ctx, RedisModuleString *keyname, RedisModuleKey *key, void *privdata);
typedef struct {
RedisModuleCtx *ctx;
void* user_data;
RedisModuleScanCB fn;
} ScanCBData;
typedef struct RedisModuleScanCursor{
int cursor;
int done;
}RedisModuleScanCursor;
static void moduleScanCallback(void *privdata, const dictEntry *de) {
ScanCBData *data = privdata;
sds key = dictGetKey(de);
robj* val = dictGetVal(de);
RedisModuleString *keyname = createObject(OBJ_STRING,sdsdup(key));
/* Setup the key handle. */
RedisModuleKey kp = {0};
moduleInitKey(&kp, data->ctx, keyname, val, REDISMODULE_READ);
data->fn(data->ctx, keyname, &kp, data->user_data);
moduleCloseKey(&kp);
decrRefCount(keyname);
}
/* Create a new cursor to be used with RedisModule_Scan */
RedisModuleScanCursor *RM_ScanCursorCreate() {
RedisModuleScanCursor* cursor = zmalloc(sizeof(*cursor));
cursor->cursor = 0;
cursor->done = 0;
return cursor;
}
/* Restart an existing cursor. The keys will be rescanned. */
void RM_ScanCursorRestart(RedisModuleScanCursor *cursor) {
cursor->cursor = 0;
cursor->done = 0;
}
/* Destroy the cursor struct. */
void RM_ScanCursorDestroy(RedisModuleScanCursor *cursor) {
zfree(cursor);
}
/* Scan API that allows a module to scan all the keys and value in
* the selected db.
*
* Callback for scan implementation.
* void scan_callback(RedisModuleCtx *ctx, RedisModuleString *keyname,
* RedisModuleKey *key, void *privdata);
* ctx - the redis module context provided to for the scan.
* keyname - owned by the caller and need to be retained if used after this
* function.
*
* key - holds info on the key and value, it is provided as best effort, in
* some cases it might be NULL, in which case the user should (can) use
* RedisModule_OpenKey (and CloseKey too).
* when it is provided, it is owned by the caller and will be free when the
* callback returns.
*
* privdata - the user data provided to RedisModule_Scan.
*
* The way it should be used:
* RedisModuleCursor *c = RedisModule_ScanCursorCreate();
* while(RedisModule_Scan(ctx, c, callback, privateData));
* RedisModule_ScanCursorDestroy(c);
*
* It is also possible to use this API from another thread while the lock
* is acquired during the actuall call to RM_Scan:
*
* RedisModuleCursor *c = RedisModule_ScanCursorCreate();
* RedisModule_ThreadSafeContextLock(ctx);
* while(RedisModule_Scan(ctx, c, callback, privateData)){
* RedisModule_ThreadSafeContextUnlock(ctx);
* // do some background job
* RedisModule_ThreadSafeContextLock(ctx);
* }
* RedisModule_ScanCursorDestroy(c);
*
* The function will return 1 if there are more elements to scan and
* 0 otherwise, possibly setting errno if the call failed.
*
* It is also possible to restart an existing cursor using RM_ScanCursorRestart.
*
* IMPORTANT: This API is very similar to the Redis SCAN command from the
* point of view of the guarantees it provides. This means that the API
* may report duplicated keys, but guarantees to report at least one time
* every key that was there from the start to the end of the scanning process.
*
* NOTE: If you do database changes within the callback, you should be aware
* that the internal state of the database may change. For instance it is safe
* to delete or modify the current key, but may not be safe to delete any
* other key.
* Moreover playing with the Redis keyspace while iterating may have the
* effect of returning more duplicates. A safe pattern is to store the keys
* names you want to modify elsewhere, and perform the actions on the keys
* later when the iteration is complete. However this can cost a lot of
* memory, so it may make sense to just operate on the current key when
* possible during the iteration, given that this is safe. */
int RM_Scan(RedisModuleCtx *ctx, RedisModuleScanCursor *cursor, RedisModuleScanCB fn, void *privdata) {
if (cursor->done) {
errno = ENOENT;
return 0;
}
int ret = 1;
ScanCBData data = { ctx, privdata, fn };
cursor->cursor = dictScan(ctx->client->db->dict, cursor->cursor, moduleScanCallback, NULL, &data);
if (cursor->cursor == 0) {
cursor->done = 1;
ret = 0;
}
errno = 0;
return ret;
}
typedef void (*RedisModuleScanKeyCB)(RedisModuleKey *key, RedisModuleString *field, RedisModuleString *value, void *privdata);
typedef struct {
RedisModuleKey *key;
void* user_data;
RedisModuleScanKeyCB fn;
} ScanKeyCBData;
static void moduleScanKeyCallback(void *privdata, const dictEntry *de) {
ScanKeyCBData *data = privdata;
sds key = dictGetKey(de);
robj *o = data->key->value;
robj *field = createStringObject(key, sdslen(key));
robj *value = NULL;
if (o->type == OBJ_SET) {
value = NULL;
} else if (o->type == OBJ_HASH) {
sds val = dictGetVal(de);
value = createStringObject(val, sdslen(val));
} else if (o->type == OBJ_ZSET) {
double *val = (double*)dictGetVal(de);
value = createStringObjectFromLongDouble(*val, 0);
}
data->fn(data->key, field, value, data->user_data);
decrRefCount(field);
if (value) decrRefCount(value);
}
/* Scan api that allows a module to scan the elements in a hash, set or sorted set key
*
* Callback for scan implementation.
* void scan_callback(RedisModuleKey *key, RedisModuleString* field, RedisModuleString* value, void *privdata);
* - key - the redis key context provided to for the scan.
* - field - field name, owned by the caller and need to be retained if used
* after this function.
* - value - value string or NULL for set type, owned by the caller and need to
* be retained if used after this function.
* - privdata - the user data provided to RedisModule_ScanKey.
*
* The way it should be used:
* RedisModuleCursor *c = RedisModule_ScanCursorCreate();
* RedisModuleKey *key = RedisModule_OpenKey(...)
* while(RedisModule_ScanKey(key, c, callback, privateData));
* RedisModule_CloseKey(key);
* RedisModule_ScanCursorDestroy(c);
*
* It is also possible to use this API from another thread while the lock is acquired during
* the actuall call to RM_ScanKey, and re-opening the key each time:
* RedisModuleCursor *c = RedisModule_ScanCursorCreate();
* RedisModule_ThreadSafeContextLock(ctx);
* RedisModuleKey *key = RedisModule_OpenKey(...)
* while(RedisModule_ScanKey(ctx, c, callback, privateData)){
* RedisModule_CloseKey(key);
* RedisModule_ThreadSafeContextUnlock(ctx);
* // do some background job
* RedisModule_ThreadSafeContextLock(ctx);
* RedisModuleKey *key = RedisModule_OpenKey(...)
* }
* RedisModule_CloseKey(key);
* RedisModule_ScanCursorDestroy(c);
*
* The function will return 1 if there are more elements to scan and 0 otherwise,
* possibly setting errno if the call failed.
* It is also possible to restart an existing cursor using RM_ScanCursorRestart.
*
* NOTE: Certain operations are unsafe while iterating the object. For instance
* while the API guarantees to return at least one time all the elements that
* are present in the data structure consistently from the start to the end
* of the iteration (see HSCAN and similar commands documentation), the more
* you play with the elements, the more duplicates you may get. In general
* deleting the current element of the data structure is safe, while removing
* the key you are iterating is not safe. */
int RM_ScanKey(RedisModuleKey *key, RedisModuleScanCursor *cursor, RedisModuleScanKeyCB fn, void *privdata) {
if (key == NULL || key->value == NULL) {
errno = EINVAL;
return 0;
}
dict *ht = NULL;
robj *o = key->value;
if (o->type == OBJ_SET) {
if (o->encoding == OBJ_ENCODING_HT)
ht = o->ptr;
} else if (o->type == OBJ_HASH) {
if (o->encoding == OBJ_ENCODING_HT)
ht = o->ptr;
} else if (o->type == OBJ_ZSET) {
if (o->encoding == OBJ_ENCODING_SKIPLIST)
ht = ((zset *)o->ptr)->dict;
} else {
errno = EINVAL;
return 0;
}
if (cursor->done) {
errno = ENOENT;
return 0;
}
int ret = 1;
if (ht) {
ScanKeyCBData data = { key, privdata, fn };
cursor->cursor = dictScan(ht, cursor->cursor, moduleScanKeyCallback, NULL, &data);
if (cursor->cursor == 0) {
cursor->done = 1;
ret = 0;
}
} else if (o->type == OBJ_SET && o->encoding == OBJ_ENCODING_INTSET) {
int pos = 0;
int64_t ll;
while(intsetGet(o->ptr,pos++,&ll)) {
robj *field = createObject(OBJ_STRING,sdsfromlonglong(ll));
fn(key, field, NULL, privdata);
decrRefCount(field);
}
cursor->cursor = 1;
cursor->done = 1;
ret = 0;
} else if (o->type == OBJ_HASH || o->type == OBJ_ZSET) {
unsigned char *p = ziplistIndex(o->ptr,0);
unsigned char *vstr;
unsigned int vlen;
long long vll;
while(p) {
ziplistGet(p,&vstr,&vlen,&vll);
robj *field = (vstr != NULL) ?
createStringObject((char*)vstr,vlen) :
createObject(OBJ_STRING,sdsfromlonglong(vll));
p = ziplistNext(o->ptr,p);
ziplistGet(p,&vstr,&vlen,&vll);
robj *value = (vstr != NULL) ?
createStringObject((char*)vstr,vlen) :
createObject(OBJ_STRING,sdsfromlonglong(vll));
fn(key, field, value, privdata);
p = ziplistNext(o->ptr,p);
decrRefCount(field);
decrRefCount(value);
}
cursor->cursor = 1;
cursor->done = 1;
ret = 0;
}
errno = 0;
return ret;
}
/* --------------------------------------------------------------------------
* Module fork API
* -------------------------------------------------------------------------- */
/* Create a background child process with the current frozen snaphost of the
* main process where you can do some processing in the background without
* affecting / freezing the traffic and no need for threads and GIL locking.
* Note that Redis allows for only one concurrent fork.
* When the child wants to exit, it should call RedisModule_ExitFromChild.
* If the parent wants to kill the child it should call RedisModule_KillForkChild
* The done handler callback will be executed on the parent process when the
* child existed (but not when killed)
* Return: -1 on failure, on success the parent process will get a positive PID
* of the child, and the child process will get 0.
*/
int RM_Fork(RedisModuleForkDoneHandler cb, void *user_data) {
pid_t childpid;
if (hasActiveChildProcess()) {
return -1;
}
openChildInfoPipe();
if ((childpid = redisFork(CHILD_TYPE_MODULE)) == 0) {
/* Child */
redisSetProcTitle("redis-module-fork");
} else if (childpid == -1) {
closeChildInfoPipe();
serverLog(LL_WARNING,"Can't fork for module: %s", strerror(errno));
} else {
/* Parent */
server.module_child_pid = childpid;
moduleForkInfo.done_handler = cb;
moduleForkInfo.done_handler_user_data = user_data;
serverLog(LL_VERBOSE, "Module fork started pid: %d ", childpid);
}
return childpid;
}
/* Call from the child process when you want to terminate it.
* retcode will be provided to the done handler executed on the parent process.
*/
int RM_ExitFromChild(int retcode) {
sendChildCOWInfo(CHILD_TYPE_MODULE, "Module fork");
exitFromChild(retcode);
return REDISMODULE_OK;
}
/* Kill the active module forked child, if there is one active and the
* pid matches, and returns C_OK. Otherwise if there is no active module
* child or the pid does not match, return C_ERR without doing anything. */
int TerminateModuleForkChild(int child_pid, int wait) {
/* Module child should be active and pid should match. */
if (server.module_child_pid == -1 ||
server.module_child_pid != child_pid) return C_ERR;
int statloc;
serverLog(LL_VERBOSE,"Killing running module fork child: %ld",
(long) server.module_child_pid);
if (kill(server.module_child_pid,SIGUSR1) != -1 && wait) {
while(wait4(server.module_child_pid,&statloc,0,NULL) !=
server.module_child_pid);
}
/* Reset the buffer accumulating changes while the child saves. */
server.module_child_pid = -1;
moduleForkInfo.done_handler = NULL;
moduleForkInfo.done_handler_user_data = NULL;
closeChildInfoPipe();
updateDictResizePolicy();
return C_OK;
}
/* Can be used to kill the forked child process from the parent process.
* child_pid would be the return value of RedisModule_Fork. */
int RM_KillForkChild(int child_pid) {
/* Kill module child, wait for child exit. */
if (TerminateModuleForkChild(child_pid,1) == C_OK)
return REDISMODULE_OK;
else
return REDISMODULE_ERR;
}
void ModuleForkDoneHandler(int exitcode, int bysignal) {
serverLog(LL_NOTICE,
"Module fork exited pid: %d, retcode: %d, bysignal: %d",
server.module_child_pid, exitcode, bysignal);
if (moduleForkInfo.done_handler) {
moduleForkInfo.done_handler(exitcode, bysignal,
moduleForkInfo.done_handler_user_data);
}
server.module_child_pid = -1;
moduleForkInfo.done_handler = NULL;
moduleForkInfo.done_handler_user_data = NULL;
}
/* --------------------------------------------------------------------------
* Server hooks implementation
* -------------------------------------------------------------------------- */
/* Register to be notified, via a callback, when the specified server event
* happens. The callback is called with the event as argument, and an additional
* argument which is a void pointer and should be cased to a specific type
* that is event-specific (but many events will just use NULL since they do not
* have additional information to pass to the callback).
*
* If the callback is NULL and there was a previous subscription, the module
* will be unsubscribed. If there was a previous subscription and the callback
* is not null, the old callback will be replaced with the new one.
*
* The callback must be of this type:
*
* int (*RedisModuleEventCallback)(RedisModuleCtx *ctx,
* RedisModuleEvent eid,
* uint64_t subevent,
* void *data);
*
* The 'ctx' is a normal Redis module context that the callback can use in
* order to call other modules APIs. The 'eid' is the event itself, this
* is only useful in the case the module subscribed to multiple events: using
* the 'id' field of this structure it is possible to check if the event
* is one of the events we registered with this callback. The 'subevent' field
* depends on the event that fired.
*
* Finally the 'data' pointer may be populated, only for certain events, with
* more relevant data.
*
* Here is a list of events you can use as 'eid' and related sub events:
*
* RedisModuleEvent_ReplicationRoleChanged
*
* This event is called when the instance switches from master
* to replica or the other way around, however the event is
* also called when the replica remains a replica but starts to
* replicate with a different master.
*
* The following sub events are available:
*
* REDISMODULE_SUBEVENT_REPLROLECHANGED_NOW_MASTER
* REDISMODULE_SUBEVENT_REPLROLECHANGED_NOW_REPLICA
*
* The 'data' field can be casted by the callback to a
* RedisModuleReplicationInfo structure with the following fields:
*
* int master; // true if master, false if replica
* char *masterhost; // master instance hostname for NOW_REPLICA
* int masterport; // master instance port for NOW_REPLICA
* char *replid1; // Main replication ID
* char *replid2; // Secondary replication ID
* uint64_t repl1_offset; // Main replication offset
* uint64_t repl2_offset; // Offset of replid2 validity
*
* RedisModuleEvent_Persistence
*
* This event is called when RDB saving or AOF rewriting starts
* and ends. The following sub events are available:
*
* REDISMODULE_SUBEVENT_PERSISTENCE_RDB_START
* REDISMODULE_SUBEVENT_PERSISTENCE_AOF_START
* REDISMODULE_SUBEVENT_PERSISTENCE_SYNC_RDB_START
* REDISMODULE_SUBEVENT_PERSISTENCE_ENDED
* REDISMODULE_SUBEVENT_PERSISTENCE_FAILED
*
* The above events are triggered not just when the user calls the
* relevant commands like BGSAVE, but also when a saving operation
* or AOF rewriting occurs because of internal server triggers.
* The SYNC_RDB_START sub events are happening in the forground due to
* SAVE command, FLUSHALL, or server shutdown, and the other RDB and
* AOF sub events are executed in a background fork child, so any
* action the module takes can only affect the generated AOF or RDB,
* but will not be reflected in the parent process and affect connected
* clients and commands. Also note that the AOF_START sub event may end
* up saving RDB content in case of an AOF with rdb-preamble.
*
* RedisModuleEvent_FlushDB
*
* The FLUSHALL, FLUSHDB or an internal flush (for instance
* because of replication, after the replica synchronization)
* happened. The following sub events are available:
*
* REDISMODULE_SUBEVENT_FLUSHDB_START
* REDISMODULE_SUBEVENT_FLUSHDB_END
*
* The data pointer can be casted to a RedisModuleFlushInfo
* structure with the following fields:
*
* int32_t async; // True if the flush is done in a thread.
* See for instance FLUSHALL ASYNC.
* In this case the END callback is invoked
* immediately after the database is put
* in the free list of the thread.
* int32_t dbnum; // Flushed database number, -1 for all the DBs
* in the case of the FLUSHALL operation.
*
* The start event is called *before* the operation is initated, thus
* allowing the callback to call DBSIZE or other operation on the
* yet-to-free keyspace.
*
* RedisModuleEvent_Loading
*
* Called on loading operations: at startup when the server is
* started, but also after a first synchronization when the
* replica is loading the RDB file from the master.
* The following sub events are available:
*
* REDISMODULE_SUBEVENT_LOADING_RDB_START
* REDISMODULE_SUBEVENT_LOADING_AOF_START
* REDISMODULE_SUBEVENT_LOADING_REPL_START
* REDISMODULE_SUBEVENT_LOADING_ENDED
* REDISMODULE_SUBEVENT_LOADING_FAILED
*
* Note that AOF loading may start with an RDB data in case of
* rdb-preamble, in which case you'll only receive an AOF_START event.
*
*
* RedisModuleEvent_ClientChange
*
* Called when a client connects or disconnects.
* The data pointer can be casted to a RedisModuleClientInfo
* structure, documented in RedisModule_GetClientInfoById().
* The following sub events are available:
*
* REDISMODULE_SUBEVENT_CLIENT_CHANGE_CONNECTED
* REDISMODULE_SUBEVENT_CLIENT_CHANGE_DISCONNECTED
*
* RedisModuleEvent_Shutdown
*
* The server is shutting down. No subevents are available.
*
* RedisModuleEvent_ReplicaChange
*
* This event is called when the instance (that can be both a
* master or a replica) get a new online replica, or lose a
* replica since it gets disconnected.
* The following sub events are available:
*
* REDISMODULE_SUBEVENT_REPLICA_CHANGE_ONLINE
* REDISMODULE_SUBEVENT_REPLICA_CHANGE_OFFLINE
*
* No additional information is available so far: future versions
* of Redis will have an API in order to enumerate the replicas
* connected and their state.
*
* RedisModuleEvent_CronLoop
*
* This event is called every time Redis calls the serverCron()
* function in order to do certain bookkeeping. Modules that are
* required to do operations from time to time may use this callback.
* Normally Redis calls this function 10 times per second, but
* this changes depending on the "hz" configuration.
* No sub events are available.
*
* The data pointer can be casted to a RedisModuleCronLoop
* structure with the following fields:
*
* int32_t hz; // Approximate number of events per second.
*
* RedisModuleEvent_MasterLinkChange
*
* This is called for replicas in order to notify when the
* replication link becomes functional (up) with our master,
* or when it goes down. Note that the link is not considered
* up when we just connected to the master, but only if the
* replication is happening correctly.
* The following sub events are available:
*
* REDISMODULE_SUBEVENT_MASTER_LINK_UP
* REDISMODULE_SUBEVENT_MASTER_LINK_DOWN
*
* RedisModuleEvent_ModuleChange
*
* This event is called when a new module is loaded or one is unloaded.
* The following sub events are available:
*
* REDISMODULE_SUBEVENT_MODULE_LOADED
* REDISMODULE_SUBEVENT_MODULE_UNLOADED
*
* The data pointer can be casted to a RedisModuleModuleChange
* structure with the following fields:
*
* const char* module_name; // Name of module loaded or unloaded.
* int32_t module_version; // Module version.
*
* RedisModuleEvent_LoadingProgress
*
* This event is called repeatedly called while an RDB or AOF file
* is being loaded.
* The following sub events are availble:
*
* REDISMODULE_SUBEVENT_LOADING_PROGRESS_RDB
* REDISMODULE_SUBEVENT_LOADING_PROGRESS_AOF
*
* The data pointer can be casted to a RedisModuleLoadingProgress
* structure with the following fields:
*
* int32_t hz; // Approximate number of events per second.
* int32_t progress; // Approximate progress between 0 and 1024,
* or -1 if unknown.
*
* RedisModuleEvent_SwapDB
*
* This event is called when a swap db command has been successfully
* Executed.
* For this event call currently there is no subevents available.
*
* The data pointer can be casted to a RedisModuleSwapDbInfo
* structure with the following fields:
*
* int32_t dbnum_first; // Swap Db first dbnum
* int32_t dbnum_second; // Swap Db second dbnum
*
*
*
* The function returns REDISMODULE_OK if the module was successfully subscribed
* for the specified event. If the API is called from a wrong context then
* REDISMODULE_ERR is returned. */
int RM_SubscribeToServerEvent(RedisModuleCtx *ctx, RedisModuleEvent event, RedisModuleEventCallback callback) {
RedisModuleEventListener *el;
/* Protect in case of calls from contexts without a module reference. */
if (ctx->module == NULL) return REDISMODULE_ERR;
/* Search an event matching this module and event ID. */
listIter li;
listNode *ln;
listRewind(RedisModule_EventListeners,&li);
while((ln = listNext(&li))) {
el = ln->value;
if (el->module == ctx->module && el->event.id == event.id)
break; /* Matching event found. */
}
/* Modify or remove the event listener if we already had one. */
if (ln) {
if (callback == NULL) {
listDelNode(RedisModule_EventListeners,ln);
zfree(el);
} else {
el->callback = callback; /* Update the callback with the new one. */
}
return REDISMODULE_OK;
}
/* No event found, we need to add a new one. */
el = zmalloc(sizeof(*el));
el->module = ctx->module;
el->event = event;
el->callback = callback;
listAddNodeTail(RedisModule_EventListeners,el);
return REDISMODULE_OK;
}
/* This is called by the Redis internals every time we want to fire an
* event that can be interceppted by some module. The pointer 'data' is useful
* in order to populate the event-specific structure when needed, in order
* to return the structure with more information to the callback.
*
* 'eid' and 'subid' are just the main event ID and the sub event associated
* with the event, depending on what exactly happened. */
void moduleFireServerEvent(uint64_t eid, int subid, void *data) {
/* Fast path to return ASAP if there is nothing to do, avoiding to
* setup the iterator and so forth: we want this call to be extremely
* cheap if there are no registered modules. */
if (listLength(RedisModule_EventListeners) == 0) return;
int real_client_used = 0;
listIter li;
listNode *ln;
listRewind(RedisModule_EventListeners,&li);
while((ln = listNext(&li))) {
RedisModuleEventListener *el = ln->value;
if (el->event.id == eid) {
RedisModuleCtx ctx = REDISMODULE_CTX_INIT;
ctx.module = el->module;
if (eid == REDISMODULE_EVENT_CLIENT_CHANGE) {
/* In the case of client changes, we're pushing the real client
* so the event handler can mutate it if needed. For example,
* to change its authentication state in a way that does not
* depend on specific commands executed later.
*/
ctx.client = (client *) data;
real_client_used = 1;
} else if (ModulesInHooks == 0) {
ctx.client = moduleFreeContextReusedClient;
} else {
ctx.client = createClient(NULL);
ctx.client->flags |= CLIENT_MODULE;
ctx.client->user = NULL; /* Root user. */
}
void *moduledata = NULL;
RedisModuleClientInfoV1 civ1;
RedisModuleReplicationInfoV1 riv1;
RedisModuleModuleChangeV1 mcv1;
/* Start at DB zero by default when calling the handler. It's
* up to the specific event setup to change it when it makes
* sense. For instance for FLUSHDB events we select the correct
* DB automatically. */
selectDb(ctx.client, 0);
/* Event specific context and data pointer setup. */
if (eid == REDISMODULE_EVENT_CLIENT_CHANGE) {
modulePopulateClientInfoStructure(&civ1,data,
el->event.dataver);
moduledata = &civ1;
} else if (eid == REDISMODULE_EVENT_REPLICATION_ROLE_CHANGED) {
modulePopulateReplicationInfoStructure(&riv1,el->event.dataver);
moduledata = &riv1;
} else if (eid == REDISMODULE_EVENT_FLUSHDB) {
moduledata = data;
RedisModuleFlushInfoV1 *fi = data;
if (fi->dbnum != -1)
selectDb(ctx.client, fi->dbnum);
} else if (eid == REDISMODULE_EVENT_MODULE_CHANGE) {
RedisModule *m = data;
if (m == el->module)
continue;
mcv1.version = REDISMODULE_MODULE_CHANGE_VERSION;
mcv1.module_name = m->name;
mcv1.module_version = m->ver;
moduledata = &mcv1;
} else if (eid == REDISMODULE_EVENT_LOADING_PROGRESS) {
moduledata = data;
} else if (eid == REDISMODULE_EVENT_CRON_LOOP) {
moduledata = data;
} else if (eid == REDISMODULE_EVENT_SWAPDB) {
moduledata = data;
}
ModulesInHooks++;
el->module->in_hook++;
el->callback(&ctx,el->event,subid,moduledata);
el->module->in_hook--;
ModulesInHooks--;
if (ModulesInHooks != 0 && !real_client_used) freeClient(ctx.client);
moduleFreeContext(&ctx);
}
}
}
/* Remove all the listeners for this module: this is used before unloading
* a module. */
void moduleUnsubscribeAllServerEvents(RedisModule *module) {
RedisModuleEventListener *el;
listIter li;
listNode *ln;
listRewind(RedisModule_EventListeners,&li);
while((ln = listNext(&li))) {
el = ln->value;
if (el->module == module) {
listDelNode(RedisModule_EventListeners,ln);
zfree(el);
}
}
}
void processModuleLoadingProgressEvent(int is_aof) {
long long now = server.ustime;
static long long next_event = 0;
if (now >= next_event) {
/* Fire the loading progress modules end event. */
int progress = -1;
if (server.loading_total_bytes)
progress = (server.loading_loaded_bytes<<10) / server.loading_total_bytes;
RedisModuleLoadingProgressV1 fi = {REDISMODULE_LOADING_PROGRESS_VERSION,
server.hz,
progress};
moduleFireServerEvent(REDISMODULE_EVENT_LOADING_PROGRESS,
is_aof?
REDISMODULE_SUBEVENT_LOADING_PROGRESS_AOF:
REDISMODULE_SUBEVENT_LOADING_PROGRESS_RDB,
&fi);
/* decide when the next event should fire. */
next_event = now + 1000000 / server.hz;
}
}
/* --------------------------------------------------------------------------
* Modules API internals
* -------------------------------------------------------------------------- */
/* server.moduleapi dictionary type. Only uses plain C strings since
* this gets queries from modules. */
uint64_t dictCStringKeyHash(const void *key) {
return dictGenHashFunction((unsigned char*)key, strlen((char*)key));
}
int dictCStringKeyCompare(void *privdata, const void *key1, const void *key2) {
UNUSED(privdata);
return strcmp(key1,key2) == 0;
}
dictType moduleAPIDictType = {
dictCStringKeyHash, /* hash function */
NULL, /* key dup */
NULL, /* val dup */
dictCStringKeyCompare, /* key compare */
NULL, /* key destructor */
NULL /* val destructor */
};
int moduleRegisterApi(const char *funcname, void *funcptr) {
return dictAdd(server.moduleapi, (char*)funcname, funcptr);
}
#define REGISTER_API(name) \
moduleRegisterApi("RedisModule_" #name, (void *)(unsigned long)RM_ ## name)
/* Global initialization at Redis startup. */
void moduleRegisterCoreAPI(void);
/* Some steps in module initialization need to be done last after server
* initialization.
* For example, selectDb() in createClient() requires that server.db has
* been initialized, see #7323. */
void moduleInitModulesSystemLast(void) {
moduleFreeContextReusedClient = createClient(NULL);
moduleFreeContextReusedClient->flags |= CLIENT_MODULE;
moduleFreeContextReusedClient->user = NULL; /* root user. */
}
void moduleInitModulesSystem(void) {
moduleUnblockedClients = listCreate();
server.loadmodule_queue = listCreate();
modules = dictCreate(&modulesDictType,NULL);
/* Set up the keyspace notification subscriber list and static client */
moduleKeyspaceSubscribers = listCreate();
/* Set up filter list */
moduleCommandFilters = listCreate();
moduleRegisterCoreAPI();
if (pipe(server.module_blocked_pipe) == -1) {
serverLog(LL_WARNING,
"Can't create the pipe for module blocking commands: %s",
strerror(errno));
exit(1);
}
/* Make the pipe non blocking. This is just a best effort aware mechanism
* and we do not want to block not in the read nor in the write half. */
anetNonBlock(NULL,server.module_blocked_pipe[0]);
anetNonBlock(NULL,server.module_blocked_pipe[1]);
/* Create the timers radix tree. */
Timers = raxNew();
/* Setup the event listeners data structures. */
RedisModule_EventListeners = listCreate();
/* Our thread-safe contexts GIL must start with already locked:
* it is just unlocked when it's safe. */
pthread_mutex_lock(&moduleGIL);
}
/* Load all the modules in the server.loadmodule_queue list, which is
* populated by `loadmodule` directives in the configuration file.
* We can't load modules directly when processing the configuration file
* because the server must be fully initialized before loading modules.
*
* The function aborts the server on errors, since to start with missing
* modules is not considered sane: clients may rely on the existence of
* given commands, loading AOF also may need some modules to exist, and
* if this instance is a slave, it must understand commands from master. */
void moduleLoadFromQueue(void) {
listIter li;
listNode *ln;
listRewind(server.loadmodule_queue,&li);
while((ln = listNext(&li))) {
struct moduleLoadQueueEntry *loadmod = ln->value;
if (moduleLoad(loadmod->path,(void **)loadmod->argv,loadmod->argc)
== C_ERR)
{
serverLog(LL_WARNING,
"Can't load module from %s: server aborting",
loadmod->path);
exit(1);
}
}
}
void moduleFreeModuleStructure(struct RedisModule *module) {
listRelease(module->types);
listRelease(module->filters);
listRelease(module->usedby);
listRelease(module->using);
sdsfree(module->name);
zfree(module);
}
void moduleUnregisterCommands(struct RedisModule *module) {
/* Unregister all the commands registered by this module. */
dictIterator *di = dictGetSafeIterator(server.commands);
dictEntry *de;
while ((de = dictNext(di)) != NULL) {
struct redisCommand *cmd = dictGetVal(de);
if (cmd->proc == RedisModuleCommandDispatcher) {
RedisModuleCommandProxy *cp =
(void*)(unsigned long)cmd->getkeys_proc;
sds cmdname = cp->rediscmd->name;
if (cp->module == module) {
dictDelete(server.commands,cmdname);
dictDelete(server.orig_commands,cmdname);
sdsfree(cmdname);
zfree(cp->rediscmd);
zfree(cp);
}
}
}
dictReleaseIterator(di);
}
/* Load a module and initialize it. On success C_OK is returned, otherwise
* C_ERR is returned. */
int moduleLoad(const char *path, void **module_argv, int module_argc) {
int (*onload)(void *, void **, int);
void *handle;
RedisModuleCtx ctx = REDISMODULE_CTX_INIT;
ctx.client = moduleFreeContextReusedClient;
selectDb(ctx.client, 0);
struct stat st;
if (stat(path, &st) == 0)
{ // this check is best effort
if (!(st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))) {
serverLog(LL_WARNING, "Module %s failed to load: It does not have execute permissions.", path);
return C_ERR;
}
}
handle = dlopen(path,RTLD_NOW|RTLD_LOCAL);
if (handle == NULL) {
serverLog(LL_WARNING, "Module %s failed to load: %s", path, dlerror());
return C_ERR;
}
onload = (int (*)(void *, void **, int))(unsigned long) dlsym(handle,"RedisModule_OnLoad");
if (onload == NULL) {
dlclose(handle);
serverLog(LL_WARNING,
"Module %s does not export RedisModule_OnLoad() "
"symbol. Module not loaded.",path);
return C_ERR;
}
if (onload((void*)&ctx,module_argv,module_argc) == REDISMODULE_ERR) {
if (ctx.module) {
moduleUnregisterCommands(ctx.module);
moduleUnregisterSharedAPI(ctx.module);
moduleUnregisterUsedAPI(ctx.module);
moduleFreeModuleStructure(ctx.module);
}
dlclose(handle);
serverLog(LL_WARNING,
"Module %s initialization failed. Module not loaded",path);
return C_ERR;
}
/* Redis module loaded! Register it. */
dictAdd(modules,ctx.module->name,ctx.module);
ctx.module->blocked_clients = 0;
ctx.module->handle = handle;
serverLog(LL_NOTICE,"Module '%s' loaded from %s",ctx.module->name,path);
/* Fire the loaded modules event. */
moduleFireServerEvent(REDISMODULE_EVENT_MODULE_CHANGE,
REDISMODULE_SUBEVENT_MODULE_LOADED,
ctx.module);
moduleFreeContext(&ctx);
return C_OK;
}
/* Unload the module registered with the specified name. On success
* C_OK is returned, otherwise C_ERR is returned and errno is set
* to the following values depending on the type of error:
*
* * ENONET: No such module having the specified name.
* * EBUSY: The module exports a new data type and can only be reloaded. */
int moduleUnload(sds name) {
struct RedisModule *module = dictFetchValue(modules,name);
if (module == NULL) {
errno = ENOENT;
return REDISMODULE_ERR;
} else if (listLength(module->types)) {
errno = EBUSY;
return REDISMODULE_ERR;
} else if (listLength(module->usedby)) {
errno = EPERM;
return REDISMODULE_ERR;
} else if (module->blocked_clients) {
errno = EAGAIN;
return REDISMODULE_ERR;
}
/* Give module a chance to clean up. */
int (*onunload)(void *);
onunload = (int (*)(void *))(unsigned long) dlsym(module->handle, "RedisModule_OnUnload");
if (onunload) {
RedisModuleCtx ctx = REDISMODULE_CTX_INIT;
ctx.module = module;
ctx.client = moduleFreeContextReusedClient;
int unload_status = onunload((void*)&ctx);
moduleFreeContext(&ctx);
if (unload_status == REDISMODULE_ERR) {
serverLog(LL_WARNING, "Module %s OnUnload failed. Unload canceled.", name);
errno = ECANCELED;
return REDISMODULE_ERR;
}
}
moduleFreeAuthenticatedClients(module);
moduleUnregisterCommands(module);
moduleUnregisterSharedAPI(module);
moduleUnregisterUsedAPI(module);
moduleUnregisterFilters(module);
/* Remove any notification subscribers this module might have */
moduleUnsubscribeNotifications(module);
moduleUnsubscribeAllServerEvents(module);
/* Unload the dynamic library. */
if (dlclose(module->handle) == -1) {
char *error = dlerror();
if (error == NULL) error = "Unknown error";
serverLog(LL_WARNING,"Error when trying to close the %s module: %s",
module->name, error);
}
/* Fire the unloaded modules event. */
moduleFireServerEvent(REDISMODULE_EVENT_MODULE_CHANGE,
REDISMODULE_SUBEVENT_MODULE_UNLOADED,
module);
/* Remove from list of modules. */
serverLog(LL_NOTICE,"Module %s unloaded",module->name);
dictDelete(modules,module->name);
module->name = NULL; /* The name was already freed by dictDelete(). */
moduleFreeModuleStructure(module);
return REDISMODULE_OK;
}
/* Helper function for the MODULE and HELLO command: send the list of the
* loaded modules to the client. */
void addReplyLoadedModules(client *c) {
dictIterator *di = dictGetIterator(modules);
dictEntry *de;
addReplyArrayLen(c,dictSize(modules));
while ((de = dictNext(di)) != NULL) {
sds name = dictGetKey(de);
struct RedisModule *module = dictGetVal(de);
addReplyMapLen(c,2);
addReplyBulkCString(c,"name");
addReplyBulkCBuffer(c,name,sdslen(name));
addReplyBulkCString(c,"ver");
addReplyLongLong(c,module->ver);
}
dictReleaseIterator(di);
}
/* Helper for genModulesInfoString(): given a list of modules, return
* am SDS string in the form "[modulename|modulename2|...]" */
sds genModulesInfoStringRenderModulesList(list *l) {
listIter li;
listNode *ln;
listRewind(l,&li);
sds output = sdsnew("[");
while((ln = listNext(&li))) {
RedisModule *module = ln->value;
output = sdscat(output,module->name);
}
output = sdstrim(output,"|");
output = sdscat(output,"]");
return output;
}
/* Helper for genModulesInfoString(): render module options as an SDS string. */
sds genModulesInfoStringRenderModuleOptions(struct RedisModule *module) {
sds output = sdsnew("[");
if (module->options & REDISMODULE_OPTIONS_HANDLE_IO_ERRORS)
output = sdscat(output,"handle-io-errors|");
output = sdstrim(output,"|");
output = sdscat(output,"]");
return output;
}
/* Helper function for the INFO command: adds loaded modules as to info's
* output.
*
* After the call, the passed sds info string is no longer valid and all the
* references must be substituted with the new pointer returned by the call. */
sds genModulesInfoString(sds info) {
dictIterator *di = dictGetIterator(modules);
dictEntry *de;
while ((de = dictNext(di)) != NULL) {
sds name = dictGetKey(de);
struct RedisModule *module = dictGetVal(de);
sds usedby = genModulesInfoStringRenderModulesList(module->usedby);
sds using = genModulesInfoStringRenderModulesList(module->using);
sds options = genModulesInfoStringRenderModuleOptions(module);
info = sdscatfmt(info,
"module:name=%S,ver=%i,api=%i,filters=%i,"
"usedby=%S,using=%S,options=%S\r\n",
name, module->ver, module->apiver,
(int)listLength(module->filters), usedby, using, options);
sdsfree(usedby);
sdsfree(using);
sdsfree(options);
}
dictReleaseIterator(di);
return info;
}
/* Redis MODULE command.
*
* MODULE LOAD <path> [args...] */
void moduleCommand(client *c) {
char *subcmd = c->argv[1]->ptr;
if (c->argc == 2 && !strcasecmp(subcmd,"help")) {
const char *help[] = {
"LIST -- Return a list of loaded modules.",
"LOAD <path> [arg ...] -- Load a module library from <path>.",
"UNLOAD <name> -- Unload a module.",
NULL
};
addReplyHelp(c, help);
} else
if (!strcasecmp(subcmd,"load") && c->argc >= 3) {
robj **argv = NULL;
int argc = 0;
if (c->argc > 3) {
argc = c->argc - 3;
argv = &c->argv[3];
}
if (moduleLoad(c->argv[2]->ptr,(void **)argv,argc) == C_OK)
addReply(c,shared.ok);
else
addReplyError(c,
"Error loading the extension. Please check the server logs.");
} else if (!strcasecmp(subcmd,"unload") && c->argc == 3) {
if (moduleUnload(c->argv[2]->ptr) == C_OK)
addReply(c,shared.ok);
else {
char *errmsg;
switch(errno) {
case ENOENT:
errmsg = "no such module with that name";
break;
case EBUSY:
errmsg = "the module exports one or more module-side data "
"types, can't unload";
break;
case EPERM:
errmsg = "the module exports APIs used by other modules. "
"Please unload them first and try again";
break;
case EAGAIN:
errmsg = "the module has blocked clients. "
"Please wait them unblocked and try again";
break;
default:
errmsg = "operation not possible.";
break;
}
addReplyErrorFormat(c,"Error unloading module: %s",errmsg);
}
} else if (!strcasecmp(subcmd,"list") && c->argc == 2) {
addReplyLoadedModules(c);
} else {
addReplySubcommandSyntaxError(c);
return;
}
}
/* Return the number of registered modules. */
size_t moduleCount(void) {
return dictSize(modules);
}
/* Set the key last access time for LRU based eviction. not relevant if the
* servers's maxmemory policy is LFU based. Value is idle time in milliseconds.
* returns REDISMODULE_OK if the LRU was updated, REDISMODULE_ERR otherwise. */
int RM_SetLRU(RedisModuleKey *key, mstime_t lru_idle) {
if (!key->value)
return REDISMODULE_ERR;
if (objectSetLRUOrLFU(key->value, -1, lru_idle, lru_idle>=0 ? LRU_CLOCK() : 0, 1))
return REDISMODULE_OK;
return REDISMODULE_ERR;
}
/* Gets the key last access time.
* Value is idletime in milliseconds or -1 if the server's eviction policy is
* LFU based.
* returns REDISMODULE_OK if when key is valid. */
int RM_GetLRU(RedisModuleKey *key, mstime_t *lru_idle) {
*lru_idle = -1;
if (!key->value)
return REDISMODULE_ERR;
if (server.maxmemory_policy & MAXMEMORY_FLAG_LFU)
return REDISMODULE_OK;
*lru_idle = estimateObjectIdleTime(key->value);
return REDISMODULE_OK;
}
/* Set the key access frequency. only relevant if the server's maxmemory policy
* is LFU based.
* The frequency is a logarithmic counter that provides an indication of
* the access frequencyonly (must be <= 255).
* returns REDISMODULE_OK if the LFU was updated, REDISMODULE_ERR otherwise. */
int RM_SetLFU(RedisModuleKey *key, long long lfu_freq) {
if (!key->value)
return REDISMODULE_ERR;
if (objectSetLRUOrLFU(key->value, lfu_freq, -1, 0, 1))
return REDISMODULE_OK;
return REDISMODULE_ERR;
}
/* Gets the key access frequency or -1 if the server's eviction policy is not
* LFU based.
* returns REDISMODULE_OK if when key is valid. */
int RM_GetLFU(RedisModuleKey *key, long long *lfu_freq) {
*lfu_freq = -1;
if (!key->value)
return REDISMODULE_ERR;
if (server.maxmemory_policy & MAXMEMORY_FLAG_LFU)
*lfu_freq = LFUDecrAndReturn(key->value);
return REDISMODULE_OK;
}
/* Replace the value assigned to a module type.
*
* The key must be open for writing, have an existing value, and have a moduleType
* that matches the one specified by the caller.
*
* Unlike RM_ModuleTypeSetValue() which will free the old value, this function
* simply swaps the old value with the new value.
*
* The function returns REDISMODULE_OK on success, REDISMODULE_ERR on errors
* such as:
*
* 1. Key is not opened for writing.
* 2. Key is not a module data type key.
* 3. Key is a module datatype other than 'mt'.
*
* If old_value is non-NULL, the old value is returned by reference.
*/
int RM_ModuleTypeReplaceValue(RedisModuleKey *key, moduleType *mt, void *new_value, void **old_value) {
if (!(key->mode & REDISMODULE_WRITE) || key->iter)
return REDISMODULE_ERR;
if (!key->value || key->value->type != OBJ_MODULE)
return REDISMODULE_ERR;
moduleValue *mv = key->value->ptr;
if (mv->type != mt)
return REDISMODULE_ERR;
if (old_value)
*old_value = mv->value;
mv->value = new_value;
return REDISMODULE_OK;
}
/* Register all the APIs we export. Keep this function at the end of the
* file so that's easy to seek it to add new entries. */
void moduleRegisterCoreAPI(void) {
server.moduleapi = dictCreate(&moduleAPIDictType,NULL);
server.sharedapi = dictCreate(&moduleAPIDictType,NULL);
REGISTER_API(Alloc);
REGISTER_API(Calloc);
REGISTER_API(Realloc);
REGISTER_API(Free);
REGISTER_API(Strdup);
REGISTER_API(CreateCommand);
REGISTER_API(SetModuleAttribs);
REGISTER_API(IsModuleNameBusy);
REGISTER_API(WrongArity);
REGISTER_API(ReplyWithLongLong);
REGISTER_API(ReplyWithError);
REGISTER_API(ReplyWithSimpleString);
REGISTER_API(ReplyWithArray);
REGISTER_API(ReplyWithNullArray);
REGISTER_API(ReplyWithEmptyArray);
REGISTER_API(ReplySetArrayLength);
REGISTER_API(ReplyWithString);
REGISTER_API(ReplyWithEmptyString);
REGISTER_API(ReplyWithVerbatimString);
REGISTER_API(ReplyWithStringBuffer);
REGISTER_API(ReplyWithCString);
REGISTER_API(ReplyWithNull);
REGISTER_API(ReplyWithCallReply);
REGISTER_API(ReplyWithDouble);
REGISTER_API(ReplyWithLongDouble);
REGISTER_API(GetSelectedDb);
REGISTER_API(SelectDb);
REGISTER_API(OpenKey);
REGISTER_API(CloseKey);
REGISTER_API(KeyType);
REGISTER_API(ValueLength);
REGISTER_API(ListPush);
REGISTER_API(ListPop);
REGISTER_API(StringToLongLong);
REGISTER_API(StringToDouble);
REGISTER_API(StringToLongDouble);
REGISTER_API(Call);
REGISTER_API(CallReplyProto);
REGISTER_API(FreeCallReply);
REGISTER_API(CallReplyInteger);
REGISTER_API(CallReplyType);
REGISTER_API(CallReplyLength);
REGISTER_API(CallReplyArrayElement);
REGISTER_API(CallReplyStringPtr);
REGISTER_API(CreateStringFromCallReply);
REGISTER_API(CreateString);
REGISTER_API(CreateStringFromLongLong);
REGISTER_API(CreateStringFromDouble);
REGISTER_API(CreateStringFromLongDouble);
REGISTER_API(CreateStringFromString);
REGISTER_API(CreateStringPrintf);
REGISTER_API(FreeString);
REGISTER_API(StringPtrLen);
REGISTER_API(AutoMemory);
REGISTER_API(Replicate);
REGISTER_API(ReplicateVerbatim);
REGISTER_API(DeleteKey);
REGISTER_API(UnlinkKey);
REGISTER_API(StringSet);
REGISTER_API(StringDMA);
REGISTER_API(StringTruncate);
REGISTER_API(SetExpire);
REGISTER_API(GetExpire);
REGISTER_API(ResetDataset);
REGISTER_API(DbSize);
REGISTER_API(RandomKey);
REGISTER_API(ZsetAdd);
REGISTER_API(ZsetIncrby);
REGISTER_API(ZsetScore);
REGISTER_API(ZsetRem);
REGISTER_API(ZsetRangeStop);
REGISTER_API(ZsetFirstInScoreRange);
REGISTER_API(ZsetLastInScoreRange);
REGISTER_API(ZsetFirstInLexRange);
REGISTER_API(ZsetLastInLexRange);
REGISTER_API(ZsetRangeCurrentElement);
REGISTER_API(ZsetRangeNext);
REGISTER_API(ZsetRangePrev);
REGISTER_API(ZsetRangeEndReached);
REGISTER_API(HashSet);
REGISTER_API(HashGet);
REGISTER_API(IsKeysPositionRequest);
REGISTER_API(KeyAtPos);
REGISTER_API(GetClientId);
REGISTER_API(GetContextFlags);
REGISTER_API(AvoidReplicaTraffic);
REGISTER_API(PoolAlloc);
REGISTER_API(CreateDataType);
REGISTER_API(ModuleTypeSetValue);
REGISTER_API(ModuleTypeReplaceValue);
REGISTER_API(ModuleTypeGetType);
REGISTER_API(ModuleTypeGetValue);
REGISTER_API(IsIOError);
REGISTER_API(SetModuleOptions);
REGISTER_API(SignalModifiedKey);
REGISTER_API(SaveUnsigned);
REGISTER_API(LoadUnsigned);
REGISTER_API(SaveSigned);
REGISTER_API(LoadSigned);
REGISTER_API(SaveString);
REGISTER_API(SaveStringBuffer);
REGISTER_API(LoadString);
REGISTER_API(LoadStringBuffer);
REGISTER_API(SaveDouble);
REGISTER_API(LoadDouble);
REGISTER_API(SaveFloat);
REGISTER_API(LoadFloat);
REGISTER_API(SaveLongDouble);
REGISTER_API(LoadLongDouble);
REGISTER_API(SaveDataTypeToString);
REGISTER_API(LoadDataTypeFromString);
REGISTER_API(EmitAOF);
REGISTER_API(Log);
REGISTER_API(LogIOError);
REGISTER_API(_Assert);
REGISTER_API(LatencyAddSample);
REGISTER_API(StringAppendBuffer);
REGISTER_API(RetainString);
REGISTER_API(HoldString);
REGISTER_API(StringCompare);
REGISTER_API(GetContextFromIO);
REGISTER_API(GetKeyNameFromIO);
REGISTER_API(GetKeyNameFromModuleKey);
REGISTER_API(BlockClient);
REGISTER_API(UnblockClient);
REGISTER_API(IsBlockedReplyRequest);
REGISTER_API(IsBlockedTimeoutRequest);
REGISTER_API(GetBlockedClientPrivateData);
REGISTER_API(AbortBlock);
REGISTER_API(Milliseconds);
REGISTER_API(GetThreadSafeContext);
REGISTER_API(FreeThreadSafeContext);
REGISTER_API(ThreadSafeContextLock);
REGISTER_API(ThreadSafeContextTryLock);
REGISTER_API(ThreadSafeContextUnlock);
REGISTER_API(DigestAddStringBuffer);
REGISTER_API(DigestAddLongLong);
REGISTER_API(DigestEndSequence);
REGISTER_API(NotifyKeyspaceEvent);
REGISTER_API(GetNotifyKeyspaceEvents);
REGISTER_API(SubscribeToKeyspaceEvents);
REGISTER_API(RegisterClusterMessageReceiver);
REGISTER_API(SendClusterMessage);
REGISTER_API(GetClusterNodeInfo);
REGISTER_API(GetClusterNodesList);
REGISTER_API(FreeClusterNodesList);
REGISTER_API(CreateTimer);
REGISTER_API(StopTimer);
REGISTER_API(GetTimerInfo);
REGISTER_API(GetMyClusterID);
REGISTER_API(GetClusterSize);
REGISTER_API(GetRandomBytes);
REGISTER_API(GetRandomHexChars);
REGISTER_API(BlockedClientDisconnected);
REGISTER_API(SetDisconnectCallback);
REGISTER_API(GetBlockedClientHandle);
REGISTER_API(SetClusterFlags);
REGISTER_API(CreateDict);
REGISTER_API(FreeDict);
REGISTER_API(DictSize);
REGISTER_API(DictSetC);
REGISTER_API(DictReplaceC);
REGISTER_API(DictSet);
REGISTER_API(DictReplace);
REGISTER_API(DictGetC);
REGISTER_API(DictGet);
REGISTER_API(DictDelC);
REGISTER_API(DictDel);
REGISTER_API(DictIteratorStartC);
REGISTER_API(DictIteratorStart);
REGISTER_API(DictIteratorStop);
REGISTER_API(DictIteratorReseekC);
REGISTER_API(DictIteratorReseek);
REGISTER_API(DictNextC);
REGISTER_API(DictPrevC);
REGISTER_API(DictNext);
REGISTER_API(DictPrev);
REGISTER_API(DictCompareC);
REGISTER_API(DictCompare);
REGISTER_API(ExportSharedAPI);
REGISTER_API(GetSharedAPI);
REGISTER_API(RegisterCommandFilter);
REGISTER_API(UnregisterCommandFilter);
REGISTER_API(CommandFilterArgsCount);
REGISTER_API(CommandFilterArgGet);
REGISTER_API(CommandFilterArgInsert);
REGISTER_API(CommandFilterArgReplace);
REGISTER_API(CommandFilterArgDelete);
REGISTER_API(Fork);
REGISTER_API(ExitFromChild);
REGISTER_API(KillForkChild);
REGISTER_API(RegisterInfoFunc);
REGISTER_API(InfoAddSection);
REGISTER_API(InfoBeginDictField);
REGISTER_API(InfoEndDictField);
REGISTER_API(InfoAddFieldString);
REGISTER_API(InfoAddFieldCString);
REGISTER_API(InfoAddFieldDouble);
REGISTER_API(InfoAddFieldLongLong);
REGISTER_API(InfoAddFieldULongLong);
REGISTER_API(GetServerInfo);
REGISTER_API(FreeServerInfo);
REGISTER_API(ServerInfoGetField);
REGISTER_API(ServerInfoGetFieldC);
REGISTER_API(ServerInfoGetFieldSigned);
REGISTER_API(ServerInfoGetFieldUnsigned);
REGISTER_API(ServerInfoGetFieldDouble);
REGISTER_API(GetClientInfoById);
REGISTER_API(PublishMessage);
REGISTER_API(SubscribeToServerEvent);
REGISTER_API(SetLRU);
REGISTER_API(GetLRU);
REGISTER_API(SetLFU);
REGISTER_API(GetLFU);
REGISTER_API(BlockClientOnKeys);
REGISTER_API(SignalKeyAsReady);
REGISTER_API(GetBlockedClientReadyKey);
REGISTER_API(GetUsedMemoryRatio);
REGISTER_API(MallocSize);
REGISTER_API(ScanCursorCreate);
REGISTER_API(ScanCursorDestroy);
REGISTER_API(ScanCursorRestart);
REGISTER_API(Scan);
REGISTER_API(ScanKey);
REGISTER_API(CreateModuleUser);
REGISTER_API(SetModuleUserACL);
REGISTER_API(FreeModuleUser);
REGISTER_API(DeauthenticateAndCloseClient);
REGISTER_API(AuthenticateClientWithACLUser);
REGISTER_API(AuthenticateClientWithUser);
}
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