caleb-brown/redict
1
0
Fork 0
mirror of https://codeberg.org/redict/redict.git synced 2025-01-22 08:08:53 -05:00
Code Issues Actions Packages Projects Releases Wiki Activity

Scripting: objects caching for Lua c->argv creation.

Browse Source 
Reusing small objects when possible is a major speedup under certain
conditions, since it is able to avoid the malloc/free pattern that
otherwise is performed for every argument in the client command vector.
This commit is contained in:
antirez 2014-05-06 15:39:14 +02:00
parent 1e4ba6e7e6
commit 4f686555ce
1 changed files with 40 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

43
src/scripting.c
View File

@ -200,6 +200,8 @@ void luaSortArray(lua_State *lua) {
lua_pop(lua,1); /* Stack: array (sorted) */
}
#define LUA_CMD_OBJCACHE_SIZE 32
#define LUA_CMD_OBJCACHE_MAX_LEN 64
int luaRedisGenericCommand(lua_State *lua, int raise_error) {
int j, argc = lua_gettop(lua);
struct redisCommand *cmd;
@ -209,6 +211,8 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) {
/* Cached across calls. */
static robj **argv = NULL;
static int argv_size = 0;
static robj *cached_objects[LUA_CMD_OBJCACHE_SIZE];
static int cached_objects_len[LUA_CMD_OBJCACHE_SIZE];
/* Require at least one argument */
if (argc == 0) {
@ -231,7 +235,20 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) {
obj_s = (char*)lua_tolstring(lua,j+1,&obj_len);
if (obj_s == NULL) break; /* Not a string. */
argv[j] = createStringObject(obj_s, obj_len);
/* Try to use a cached object. */
if (cached_objects[j] && cached_objects_len[j] >= obj_len) {
char *s = cached_objects[j]->ptr;
struct sdshdr *sh = (void*)(s-(sizeof(struct sdshdr)));
argv[j] = cached_objects[j];
cached_objects[j] = NULL;
memcpy(s,obj_s,obj_len+1);
sh->free += sh->len - obj_len;
sh->len = obj_len;
} else {
argv[j] = createStringObject(obj_s, obj_len);
}
}
/* Check if one of the arguments passed by the Lua script
@ -348,8 +365,28 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) {
cleanup:
/* Clean up. Command code may have changed argv/argc so we use the
* argv/argc of the client instead of the local variables. */
for (j = 0; j < c->argc; j++)
decrRefCount(c->argv[j]);
for (j = 0; j < c->argc; j++) {
robj *o = c->argv[j];
/* Try to cache the object in the cached_objects array.
* The object must be small, SDS-encoded, and with refcount = 1
* (we must be the only owner) for us to cache it. */
if (j < LUA_CMD_OBJCACHE_SIZE &&
o->refcount == 1 &&
(o->encoding == REDIS_ENCODING_RAW ||
o->encoding == REDIS_ENCODING_EMBSTR) &&
sdslen(o->ptr) <= LUA_CMD_OBJCACHE_MAX_LEN)
{
struct sdshdr *sh = (void*)(((char*)(o->ptr))-(sizeof(struct sdshdr)));
if (cached_objects[j]) decrRefCount(cached_objects[j]);
cached_objects[j] = o;
cached_objects_len[j] = sh->free + sh->len;
} else {
decrRefCount(o);
}
}
if (c->argv != argv) {
zfree(c->argv);
argv = NULL;