Commit Graph

1033 Commits

Author SHA1 Message Date
Oran Agra
fad0b0d2a6
Fix error stats and failed command stats for blocked clients (#10309)
This is a followup work for #10278, and a discussion about #10279

The changes:
- fix failed_calls in command stats for blocked clients that got error.
  including CLIENT UNBLOCK, and module replying an error from a thread.
- fix latency stats for XREADGROUP that filed with -NOGROUP

Theory behind which errors should be counted:
- error stats represents errors returned to the user, so an error handled by a
  module should not be counted.
- total error counter should be the same.
- command stats represents execution of commands (even with RM_Call, and if
  they fail or get rejected it counts these calls in commandstats, so it should
  also count failed_calls)

Some thoughts about Scripts:
for scripts it could be different since they're part of user code, not the infra (not an extension to redis)
we certainly want commandstats to contain all calls and errors
a simple script is like mult-exec transaction so an error inside it should be counted in error stats
a script that replies with an error to the user (using redis.error_reply) should also be counted in error stats
but then the problem is that a plain `return redis.call("SET")` should not be counted twice (once for the SET
and once for EVAL)
so that's something left to be resolved in #10279
2022-02-21 11:20:41 +02:00
yoav-steinberg
b59bb9b476
Fix script active defrag test (#10318)
This includes two fixes:
* We forgot to count non-key reallocs in defragmentation stats.
* Fix the script defrag tests so to make dict entries less signigicant in fragmentation by making the scripts larger.
This assures active defrage will complete and reach desired results.
Some inherent fragmentation might exists in dict entries which we need to ignore.
This lead to occasional CI failures.
2022-02-21 09:37:25 +02:00
qetu3790
b2d393b990
Fix geo search bounding box check causing missing results (#10018)
Consider the following example:
1. geoadd k1 -0.15307903289794921875 85 n1 0.3515625 85.00019260486917005437 n2.
2. geodist k1 n1 n2 returns  "4891.9380"
3. but GEORADIUSBYMEMBER k1 n1 4891.94 m only returns n1.
n2 is in the  boundingbox but out of search areas.So we let  search areas contain boundingbox to get n2.

Co-authored-by: Binbin <binloveplay1314@qq.com>
2022-02-21 08:06:58 +02:00
Oran Agra
b099889a3a
Fix and improve module error reply statistics (#10278)
This PR handles several aspects
1. Calls to RM_ReplyWithError from thread safe contexts don't violate thread safety.
2. Errors returning from RM_Call to the module aren't counted in the statistics (they
  might be handled silently by the module)
3. When a module propagates a reply it got from RM_Call to it's client, then the error
  statistics are counted.

This is done by:
1. When appending an error reply to the output buffer, we avoid updating the global
  error statistics, instead we cache that error in a deferred list in the client struct.
2. When creating a RedisModuleCallReply object, the deferred error list is moved from
  the client into that object.
3. when a module calls RM_ReplyWithCallReply we copy the deferred replies to the dest
  client (if that's a real client, then that's when the error statistics are updated to the server)

Note about RM_ReplyWithCallReply: if the original reply had an array with errors, and the module
replied with just a portion of the original reply, and not the entire reply, the errors are currently not
propagated and the errors stats will not get propagated.

Fix #10180
2022-02-13 18:37:32 +02:00
yoav-steinberg
2eb9b19612
Fix Eval scripts defrag (broken 7.0 in RC1) (#10271)
Remove scripts defragger since it was broken since #10126 (released in 7.0 RC1).
would crash the server if defragger starts in a server that contains eval scripts.

In #10126 the global `lua_script` dict became a dict to a custom `luaScript` struct with an internal `robj`
in it instead of a generic `sds` -> `robj` dict. This means we need custom code to defrag it and since scripts
should never really cause much fragmentation it makes more sense to simply remove the defrag code for scripts.
2022-02-11 21:58:05 +02:00
sundb
5f0119ca91
Fix duplicate module options define (#10284)
The bug is introduced by #9323. (released in 7.0 RC1)
The define of `REDISMODULE_OPTIONS_HANDLE_IO_ERRORS` and `REDISMODULE_OPTION_NO_IMPLICIT_SIGNAL_MODIFIED` have the same value.

This will result in skipping `signalModifiedKey()` after `RM_CloseKey()` if the module has set
`REDISMODULE_OPTIONS_HANDLE_REPL_ASYNC_LOAD` option.
The implication is missing WATCH and client side tracking invalidations.

Other changes:
- add `no-implicit-signal-modified` to the options in INFO modules

Co-authored-by: Oran Agra <oran@redislabs.com>
2022-02-11 20:15:52 +02:00
Wen Hui
64e1e7e207
Add AUTH arity test (#10266)
Add test for AUTH with too many arguments
2022-02-09 22:09:20 +02:00
Wen Hui
2e1bc942aa
Make INFO command variadic (#6891)
This is an enhancement for INFO command, previously INFO only support one argument
for different info section , if user want to get more categories information, either perform
INFO all / default or calling INFO for multiple times.

**Description of the feature**

The goal of adding this feature is to let the user retrieve multiple categories via the INFO
command, and still avoid emitting the same section twice.

A use case for this is like Redis Sentinel, which periodically calling INFO command to refresh
info from monitored Master/Slaves, only Server and Replication part categories are used for
parsing information. If the INFO command can return just enough categories that client side
needs, it can save a lot of time for client side parsing it as well as network bandwidth.

**Implementation**
To share code between redis, sentinel, and other users of INFO (DEBUG and modules),
we have a new `genInfoSectionDict` function that returns a dict and some boolean flags
(e.g. `all`) to the caller (built from user input).
Sentinel is later purging unwanted sections from that, and then it is forwarded to the info `genRedisInfoString`.

**Usage Examples**
INFO Server Replication   
INFO CPU Memory
INFO default commandstats

Co-authored-by: Oran Agra <oran@redislabs.com>
2022-02-08 13:14:42 +02:00
yoav-steinberg
b76016a948
Consistent erros returned from EVAL scripts (#10218)
This PR handles inconsistencies in errors returned from lua scripts.
Details of the problem can be found in #10165.

### Changes

- Remove double stack trace. It's enough that a stack trace is automatically added by the engine's error handler
  see d0bc4fff18/src/function_lua.c (L472-L485)
  and d0bc4fff18/src/eval.c (L243-L255)
- Make sure all errors a preceded with an error code. Passing a simple string to `luaPushError()` will prepend it
  with a generic `ERR` error code.
- Make sure lua error table doesn't include a RESP `-` error status. Lua stores redis error's as a lua table with a
  single `err` field and a string. When the string is translated back to RESP we add a `-` to it.
  See d0bc4fff18/src/script_lua.c (L510-L517)
  So there's no need to store it in the lua table.

### Before & After
```diff
--- <unnamed>
+++ <unnamed>
@@ -1,14 +1,14 @@
  1: config set maxmemory 1
  2: +OK
  3: eval "return redis.call('set','x','y')" 0
- 4: -ERR Error running script (call to 71e6319f97b0fe8bdfa1c5df3ce4489946dda479): @user_script:1: @user_script: 1: -OOM command not allowed when used memory > 'maxmemory'.
+ 4: -ERR Error running script (call to 71e6319f97b0fe8bdfa1c5df3ce4489946dda479): @user_script:1: OOM command not allowed when used memory > 'maxmemory'.
  5: eval "return redis.pcall('set','x','y')" 0
- 6: -@user_script: 1: -OOM command not allowed when used memory > 'maxmemory'.
+ 6: -OOM command not allowed when used memory > 'maxmemory'.
  7: eval "return redis.call('select',99)" 0
  8: -ERR Error running script (call to 4ad5abfc50bbccb484223905f9a16f09cd043ba8): @user_script:1: ERR DB index is out of range
  9: eval "return redis.pcall('select',99)" 0
 10: -ERR DB index is out of range
 11: eval_ro "return redis.call('set','x','y')" 0
-12: -ERR Error running script (call to 71e6319f97b0fe8bdfa1c5df3ce4489946dda479): @user_script:1: @user_script: 1: Write commands are not allowed from read-only scripts.
+12: -ERR Error running script (call to 71e6319f97b0fe8bdfa1c5df3ce4489946dda479): @user_script:1: ERR Write commands are not allowed from read-only scripts.
 13: eval_ro "return redis.pcall('set','x','y')" 0
-14: -@user_script: 1: Write commands are not allowed from read-only scripts.
+14: -ERR Write commands are not allowed from read-only scripts.
```
2022-02-08 11:44:40 +02:00
guybe7
3c3e6cc1c7
X[AUTO]CLAIM should skip deleted entries (#10227)
Fix #7021 #8924 #10198

# Intro
Before this commit X[AUTO]CLAIM used to transfer deleted entries from one
PEL to another, but reply with "nil" for every such entry (instead of the entry id).
The idea (for XCLAIM) was that the caller could see this "nil", realize the entry
no longer exists, and XACK it in order to remove it from PEL.
The main problem with that approach is that it assumes there's a correlation
between the index of the "id" arguments and the array indices, which there
isn't (in case some of the input IDs to XCLAIM never existed/read):

```
127.0.0.1:6379> XADD x 1 f1 v1
"1-0"
127.0.0.1:6379> XADD x 2 f1 v1
"2-0"
127.0.0.1:6379> XADD x 3 f1 v1
"3-0"
127.0.0.1:6379> XGROUP CREATE x grp 0
OK
127.0.0.1:6379> XREADGROUP GROUP grp Alice COUNT 2 STREAMS x >
1) 1) "x"
   2) 1) 1) "1-0"
         2) 1) "f1"
            2) "v1"
      2) 1) "2-0"
         2) 1) "f1"
            2) "v1"
127.0.0.1:6379> XDEL x 1 2
(integer) 2
127.0.0.1:6379> XCLAIM x grp Bob 0 0-99 1-0 1-99 2-0
1) (nil)
2) (nil)
```

# Changes
Now,  X[AUTO]CLAIM acts in the following way:
1. If one tries to claim a deleted entry, we delete it from the PEL we found it in
  (and the group PEL too). So de facto, such entry is not claimed, just cleared
  from PEL (since anyway it doesn't exist in the stream)
2. since we never claim deleted entries, X[AUTO]CLAIM will never return "nil"
  instead of an entry.
3. add a new element to XAUTOCLAIM's response (see below)

# Knowing which entries were cleared from the PEL
The caller may want to log any entries that were found in a PEL but deleted from
the stream itself (it would suggest that there might be a bug in the application:
trimming the stream while some entries were still no processed by the consumers)

## XCLAIM
the set {XCLAIM input ids} - {XCLAIM returned ids} contains all the entry ids that were
not claimed which means they were deleted (assuming the input contains only entries
from some PEL). The user doesn't need to XACK them because XCLAIM had already
deleted them from the source PEL.

## XAUTOCLAIM
XAUTOCLAIM has a new element added to its reply: it's an array of all the deleted
stream IDs it stumbled upon.

This is somewhat of a breaking change since X[AUTO]CLAIM used to be able to reply
with "nil" and now it can't... But since it was undocumented (and generally a bad idea
to rely on it, as explained above) the breakage is not that bad.
2022-02-08 10:20:09 +02:00
Oran Agra
66be30f7fc
Handle key-spec flags with modules (#10237)
- add COMMAND GETKEYSANDFLAGS sub-command
- add RM_KeyAtPosWithFlags and GetCommandKeysWithFlags
- RM_KeyAtPos and RM_CreateCommand set flags requiring full access for keys
- RM_CreateCommand set VARIABLE_FLAGS
- expose `variable_flags` flag in COMMAND INFO key-specs
- getKeysFromCommandWithSpecs prefers key-specs over getkeys-api
- add tests for all of these
2022-02-08 10:01:35 +02:00
Binbin
7f4cca11dc
COMMAND DOCS avoid adding summary/since if they don't exist (#10252)
If summary or since is empty, we used to return NULL in
COMMAND DOCS. Currently all redis commands will have these
two fields.

But not for module command, summary and since are optional
for RM_SetCommandInfo. With the change in #10043, if a module
command doesn't have the summary or since, redis-cli will
crash (see #10250).

In this commit, COMMAND DOCS avoid adding summary or since
when they are missing.
2022-02-07 19:57:50 +02:00
yoav-steinberg
9dfeda58ed
acl check api for functions and eval (#10220)
Changes:
1. Adds the `redis.acl_check_cmd()` api to lua scripts. It can be used to check if the
  current user has permissions to execute a given command. The new function receives
  the command to check as an argument exactly like `redis.call()` receives the command
  to execute as an argument.
2. In the PR I unified the code used to convert lua arguments to redis argv arguments from
  both the new `redis.acl_check_cmd()` API and the `redis.[p]call()` API. This cleans up
  potential duplicate code.
3. While doing the refactoring in 2 I noticed there's an optimization to reduce allocation calls
  when parsing lua arguments into an `argv` array in the `redis.[p]call()` implementation.
  These optimizations were introduced years ago in 48c49c4851
  and 4f686555ce. It is unclear why this was added.
  The original commit message claims a 4% performance increase which I couldn't recreate
  and might not be worth it even if it did recreate. This PR removes that optimization.
  Following are details of the benchmark I did that couldn't reveal any performance
  improvements due to this optimization:

```
benchmark 1: src/redis-benchmark -P 500 -n 10000000 eval 'return redis.call("ping")' 0
benchmark 2: src/redis-benchmark -P 500 -r 1000 -n 1000000 eval 'return redis.call("mset","k1__rand_int__","v1__rand_int__","k2__rand_int__","v2__rand_int__","k3__rand_int__","v3__rand_int__","k4__rand_int__","v4__rand_int__")' 0
benchmark 3: src/redis-benchmark -P 500 -r 1000 -n 100000 eval "for i=1,100,1 do redis.call('set','kk'..i,'vv'..__rand_int__) end return redis.call('get','kk5')" 0
benchmark 4: src/redis-benchmark -P 500 -r 1000 -n 1000000 eval 'return redis.call("mset","k1__rand_int__","v1__rand_int__","k2__rand_int__","v2__rand_int__","k3__rand_int__","v3__rand_int__","k4__rand_int__","v4__rand_int__xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx")'
```
I ran the benchmark on this branch with and without commit 68b71680a4d3bb8f0509e06578a9f15d05b92a47
Results in requests per second:
cmd | without optimization | without optimization 2nd run | with original optimization | with original optimization 2nd run
-- | -- | -- | -- | --
1 | 461233.34 | 477395.31 | 471098.16 | 469946.91
2 | 34774.14 | 35469.8 | 35149.38 | 34464.93
3 | 6390.59 | 6281.41 | 6146.28 | 6464.12
4 | 28005.71 |   | 27965.77 |  

As you can see, different use cases showed identical or negligible performance differences.
So finally I decided to chuck the original optimization and simplify the code.
2022-02-07 08:04:01 +02:00
Oran Agra
98b3f52599
add test suite infra to test RESP3 attributes (#10247)
So far we only tested attributes using readraw, not the
resp parser caches them, so that after getting the reply,
you can query them if you want.
2022-02-07 00:10:05 +02:00
Wen Hui
6ebb679f06
Add tests for ACL command error cases (#10183) 2022-02-06 07:58:28 +02:00
Viktor Söderqvist
0a82fe8447
Command info module API (#10108)
Adds RM_SetCommandInfo, allowing modules to provide the following command info:

* summary
* complexity
* since
* history
* hints
* arity
* key specs
* args

This information affects the output of `COMMAND`, `COMMAND INFO` and `COMMAND DOCS`,
Cluster, ACL and is used to filter commands with the wrong number of arguments before
the call reaches the module code.

The recently added API functions for key specs (never released) are removed.

A minimalist example would look like so:
```c
    RedisModuleCommand *mycmd = RedisModule_GetCommand(ctx,"mymodule.mycommand");
    RedisModuleCommandInfo mycmd_info = {
        .version = REDISMODULE_COMMAND_INFO_VERSION,
        .arity = -5,
        .summary = "some description",
    };
    if (RedisModule_SetCommandInfo(mycmd, &mycmd_info) == REDISMODULE_ERR)
        return REDISMODULE_ERR;
````

Notes:
* All the provided information (including strings) is copied, not keeping references to the API input data.
* The version field is actually a static struct that contains the sizes of the the structs used in arrays,
  so we can extend these in the future and old version will still be able to take the part they can support.
2022-02-04 21:09:36 +02:00
郭伟光
6b5b3ca414
forbid module to unload when it holds ongoing timer (#10187)
This is done to avoid a crash when the timer fires after the module was unloaded.
Or memory leaks in case we wanted to just ignore the timer.
It'll cause the MODULE UNLOAD command to return with an error

Co-authored-by: sundb <sundbcn@gmail.com>
2022-02-01 14:54:11 +02:00
Meir Shpilraien (Spielrein)
6ca97da0fc
Fix wrong version calculation on Redis Function tests. (#10217) 2022-01-31 12:49:57 +02:00
Harkrishn Patro
a43b6922d1
Set default channel permission to resetchannels for 7.0 (#10181)
For backwards compatibility in 6.x, channels default permission was set to `allchannels` however with 7.0,
we should modify it and the default value should be `resetchannels` for better security posture.
Also, with selectors in ACL, a client doesn't have to set channel rules everytime and by default
the value will be `resetchannels`.

Before this change
```
127.0.0.1:6379> acl list
1) "user default on nopass ~* &* +@all"
127.0.0.1:6379>  acl setuser hp on nopass +@all ~*
OK
127.0.0.1:6379> acl list
1) "user default on nopass ~* &* +@all"
2) "user hp on nopass ~* &* +@all"
127.0.0.1:6379>  acl setuser hp1 on nopass -@all (%R~sales*)
OK
127.0.0.1:6379> acl list
1) "user default on nopass ~* &* +@all"
2) "user hp on nopass ~* &* +@all"
3) "user hp1 on nopass &* -@all (%R~sales* &* -@all)"
```

After this change
```
127.0.0.1:6379> acl list
1) "user default on nopass ~* &* +@all"
127.0.0.1:6379> acl setuser hp on nopass +@all ~*
OK
127.0.0.1:6379> acl list
1) "user default on nopass ~* &* +@all"
2) "user hp on nopass ~* resetchannels +@all"
127.0.0.1:6379> acl setuser hp1 on nopass -@all (%R~sales*)
OK
127.0.0.1:6379> acl list
1) "user default on nopass ~* &* +@all"
2) "user hp on nopass ~* resetchannels +@all"
3) "user hp1 on nopass resetchannels -@all (%R~sales* resetchannels -@all)"
```
2022-01-30 12:02:55 +02:00
Binbin
d616925835
Allow SET without GET arg on write-only ACL. Allow BITFIELD GET on read-only ACL (#10148)
SET is a R+W command, because it can also do `GET` on the data.
SET without GET is a write-only command.
SET with GET is a read+write command.

In #9974, we added ACL to let users define write-only access.
So when the user uses SET with GET option, and the user doesn't
have the READ permission on the key, we need to reject it,
but we rather not reject users with write-only permissions from using
the SET command when they don't use GET.

In this commit, we add a `getkeys_proc` function to control key
flags in SET command. We also add a new key spec flag (VARIABLE_FLAGS)
means that some keys might have different flags depending on arguments.

We also handle BITFIELD command, add a `bitfieldGetKeys` function.
BITFIELD GET is a READ ONLY command.
BITFIELD SET or BITFIELD INCR are READ WRITE commands.

Other changes:
1. SET GET was added in 6.2, add the missing since in set.json
2. Added tests to cover the changes in acl-v2.tcl
3. Fix some typos in server.h and cleanups in acl-v2.tcl

Co-authored-by: Madelyn Olson <madelyneolson@gmail.com>
Co-authored-by: Oran Agra <oran@redislabs.com>
2022-01-26 21:03:21 +02:00
Meir Shpilraien (Spielrein)
5a38ccc253
Added engine stats to FUNCTION STATS command. (#10179)
Added the following statistics (per engine) to FUNCTION STATS command:
* number of functions
* number of libraries

Output example:
```
> FUNCTION stats
1) "running_script"
2) (nil)
3) "engines"
4) 1) "LUA"
   2) 1) "libraries_count"
      2) (integer) 1
      3) "functions_count"
      4) (integer) 1
```

To collect the stats, added a new dictionary to libraries_ctx that contains
for each engine, the engine statistics representing the current libraries_ctx.
Update the stats on:
1. Link library to libraries_ctx
2. Unlink library from libraries_ctx
3. Flushing libraries_ctx
2022-01-25 15:50:14 +02:00
Madelyn Olson
823da54361
Improve testing and update flags around commands without ACL keyspec flags (#10167)
This PR aims to improve the flags associated with some commands and adds various tests around
these cases. Specifically, it's concerned with commands which declare keys but have no ACL
flags (think `EXISTS`), the user needs either read or write permission to access this type of key.

This change is primarily concerned around commands in three categories:

# General keyspace commands
These commands are agnostic to the underlying data outside of side channel attacks, so they are not
marked as ACCESS.
* TOUCH
* EXISTS
* TYPE
* OBJECT 'all subcommands'

Note that TOUCH is not a write command, it could be a side effect of either a read or a write command.

# Length and cardinality commands
These commands are marked as NOT marked as ACCESS since they don't return actual user strings,
just metadata.
* LLEN
* STRLEN
* SCARD
* HSTRLEN

# Container has member commands
These commands return information about the existence or metadata about the key. These commands
are NOT marked as ACCESS since the check of membership is used widely in write commands
e.g. the response of HSET. 
* SISMEMBER
* HEXISTS

# Intersection cardinality commands
These commands are marked as ACCESS since they process data to compute the result.
* PFCOUNT
* ZCOUNT
* ZINTERCARD
* SINTERCARD
2022-01-25 09:55:30 +02:00
Madelyn Olson
c275010fff
Correctly handle minimum arity checks in scripts (#10171)
Correctly handle variable arity checks in scripts
2022-01-24 22:08:57 -08:00
yoav-steinberg
7eadc5ee70
Support function flags in script EVAL via shebang header (#10126)
In #10025 we added a mechanism for flagging certain properties for Redis Functions.
This lead us to think we'd like to "port" this mechanism to Redis Scripts (`EVAL`) as well. 

One good reason for this, other than the added functionality is because it addresses the
poor behavior we currently have in `EVAL` in case the script performs a (non DENY_OOM) write operation
during OOM state. See #8478 (And a previous attempt to handle it via #10093) for details.
Note that in Redis Functions **all** write operations (including DEL) will return an error during OOM state
unless the function is flagged as `allow-oom` in which case no OOM checking is performed at all.

This PR:
- Enables setting `EVAL` (and `SCRIPT LOAD`) script flags as defined in #10025.
- Provides a syntactical framework via [shebang](https://en.wikipedia.org/wiki/Shebang_(Unix)) for
  additional script annotations and even engine selection (instead of just lua) for scripts.
- Provides backwards compatibility so scripts without the new annotations will behave as they did before.
- Appropriate tests.
- Changes `EVAL[SHA]/_RO` to be flagged as `STALE` commands. This makes it possible to flag individual
  scripts as `allow-stale` or not flag them as such. In backwards compatibility mode these commands will
  return the `MASTERDOWN` error as before.
- Changes `SCRIPT LOAD` to be flagged as a `STALE` command. This is mainly to make it logically
  compatible with the change to `EVAL` in the previous point. It enables loading a script on a stale server
  which is technically okay it doesn't relate directly to the server's dataset. Running the script does, but that
  won't work unless the script is explicitly marked as `allow-stale`.

Note that even though the LUA syntax doesn't support hash tag comments `.lua` files do support a shebang
tag on the top so they can be executed on Unix systems like any shell script. LUA's `luaL_loadfile` handles
this as part of the LUA library. In the case of `luaL_loadbuffer`, which is what Redis uses, I needed to fix the
input script in case of a shebang manually. I did this the same way `luaL_loadfile` does, by replacing the
first line with a single line feed character.
2022-01-24 16:50:02 +02:00
Viktor Söderqvist
857dc5bacd
Disable keyspec module API in 7.0 RC1 (#10135)
The keyspec API is not yet released and there is a plan to change it
in #10108, which is going to be included in RC2. Therefore, we hide
it in RC1 to avoid introducing a breaking change in RC2.

Co-authored-by: Oran Agra <oran@redislabs.com>
2022-01-24 15:02:07 +02:00
Binbin
23325c135f
sub-command support for ACL CAT and COMMAND LIST. redisCommand always stores fullname (#10127)
Summary of changes:
1. Rename `redisCommand->name` to `redisCommand->declared_name`, it is a
  const char * for native commands and SDS for module commands.
2. Store the [sub]command fullname in `redisCommand->fullname` (sds).
3. List subcommands in `ACL CAT`
4. List subcommands in `COMMAND LIST`
5. `moduleUnregisterCommands` now will also free the module subcommands.
6. RM_GetCurrentCommandName returns full command name

Other changes:
1. Add `addReplyErrorArity` and `addReplyErrorExpireTime`
2. Remove `getFullCommandName` function that now is useless.
3. Some cleanups about `fullname` since now it is SDS.
4. Delete `populateSingleCommand` function from server.h that is useless.
5. Added tests to cover this change.
6. Add some module unload tests and fix the leaks
7. Make error messages uniform, make sure they always contain the full command
  name and that it's quoted.
7. Fixes some typos

see the history in #9504, fixes #10124

Co-authored-by: Oran Agra <oran@redislabs.com>
Co-authored-by: guybe7 <guy.benoish@redislabs.com>
2022-01-23 10:05:06 +02:00
guybe7
a6fd2a46d1
Improved handling of subcommands (don't allow ACL on first-arg of a sub-command) (#10147)
Recently we added extensive support for sub-commands in for redis 7.0,
this meant that the old ACL mechanism for
sub-commands wasn't needed, or actually was improved (to handle both include
and exclude control, like for commands), but only for real sub-commands.
The old mechanism in ACL was renamed to first-arg, and was able to match the
first argument of any command (including sub-commands).
We now realized that we might wanna completely delete that first-arg feature some
day, so the first step was not to give it new capabilities in 7.0 and it didn't have before.

Changes:
1. ACL: Block the first-arg mechanism on subcommands (we keep if in non-subcommands
  for backward compatibility)
2. COMMAND: When looking up a command, insist the command name doesn't contain
  extra words. Example: When a user issues `GET key` we want `lookupCommand` to return
  `getCommand` but when if COMMAND calls `lookupCommand` with `get|key` we want it to fail.

Other changes:
1. ACLSetUser: prevent a redundant command lookup
2022-01-22 14:09:40 +02:00
Madelyn Olson
55c81f2cd3
ACL V2 - Selectors and key based permissions (#9974)
* Implemented selectors which provide multiple different sets of permissions to users
* Implemented key based permissions 
* Added a new ACL dry-run command to test permissions before execution
* Updated module APIs to support checking key based permissions

Co-authored-by: Oran Agra <oran@redislabs.com>
2022-01-20 13:05:27 -08:00
perryitay
c4b788230c
Adding module api for processing commands during busy jobs and allow flagging the commands that should be handled at this status (#9963)
Some modules might perform a long-running logic in different stages of Redis lifetime, for example:
* command execution
* RDB loading
* thread safe context

During this long-running logic Redis is not responsive.

This PR offers 
1. An API to process events while a busy command is running (`RM_Yield`)
2. A new flag (`ALLOW_BUSY`) to mark the commands that should be handled during busy
  jobs which can also be used by modules (`allow-busy`)
3. In slow commands and thread safe contexts, this flag will start rejecting commands with -BUSY only
  after `busy-reply-threshold`
4. During loading (`rdb_load` callback), it'll process events right away (not wait for `busy-reply-threshold`),
  but either way, the processing is throttled to the server hz rate.
5. Allow modules to Yield to redis background tasks, but not to client commands

* rename `script-time-limit` to `busy-reply-threshold` (an alias to the pre-7.0 `lua-time-limit`)

Co-authored-by: Oran Agra <oran@redislabs.com>
2022-01-20 09:05:53 +02:00
Meir Shpilraien (Spielrein)
c556c57e5e
Added AOF rewrite support for functions. (#10141)
Function PR was merged without AOF rw support because we thought this feature was going
to be removed on Redis 7.

Tests was added on aofrw.tcl
Other existing aofrw tests where slow due to unwanted rdb-key-save-delay

Co-authored-by: Oran Agra <oran@redislabs.com>
2022-01-19 21:21:42 +02:00
Ozan Tezcan
1af0a2c5ae
Fix eventloop module test for valgrind (#10139)
was eating too much memory, and taking too long with valgrind
2022-01-19 09:13:51 +02:00
Oran Agra
eef9c6b0ee
New detailed key-spec flags (RO, RW, OW, RM, ACCESS, UPDATE, INSERT, DELETE) (#10122)
The new ACL key based permissions in #9974 require the key-specs (#8324) to have more
explicit flags rather than just READ and WRITE. See discussion in #10040

This PR defines two groups of flags:
One about how redis internally handles the key (mutually-exclusive).
The other is about the logical operation done from the user's point of view (3 mutually exclusive
write flags, and one read flag, all optional).
In both groups, if we can't explicitly flag something as explicit read-only, delete-only, or
insert-only, we flag it as `RW` or `UPDATE`.
here's the definition from the code:
```
/* Key-spec flags *
 * -------------- */
/* The following refer what the command actually does with the value or metadata
 * of the key, and not necessarily the user data or how it affects it.
 * Each key-spec may must have exaclty one of these. Any operation that's not
 * distinctly deletion, overwrite or read-only would be marked as RW. */
#define CMD_KEY_RO (1ULL<<0)     /* Read-Only - Reads the value of the key, but
                                  * doesn't necessarily returns it. */
#define CMD_KEY_RW (1ULL<<1)     /* Read-Write - Modifies the data stored in the
                                  * value of the key or its metadata. */
#define CMD_KEY_OW (1ULL<<2)     /* Overwrite - Overwrites the data stored in
                                  * the value of the key. */
#define CMD_KEY_RM (1ULL<<3)     /* Deletes the key. */
/* The follwing refer to user data inside the value of the key, not the metadata
 * like LRU, type, cardinality. It refers to the logical operation on the user's
 * data (actual input strings / TTL), being used / returned / copied / changed,
 * It doesn't refer to modification or returning of metadata (like type, count,
 * presence of data). Any write that's not INSERT or DELETE, would be an UPADTE.
 * Each key-spec may have one of the writes with or without access, or none: */
#define CMD_KEY_ACCESS (1ULL<<4) /* Returns, copies or uses the user data from
                                  * the value of the key. */
#define CMD_KEY_UPDATE (1ULL<<5) /* Updates data to the value, new value may
                                  * depend on the old value. */
#define CMD_KEY_INSERT (1ULL<<6) /* Adds data to the value with no chance of,
                                  * modification or deletion of existing data. */
#define CMD_KEY_DELETE (1ULL<<7) /* Explicitly deletes some content
                                  * from the value of the key. */
```

Unrelated changes:
- generate-command-code.py is only compatible with python3 (modified the shabang)
- generate-command-code.py print file on json parsing error
- rename `shard_channel` key-spec flag to just `channel`.
- add INCOMPLETE flag in input spec of SORT and SORT_RO
2022-01-18 16:00:00 +02:00
Ozan Tezcan
99ab4236af
Add event loop support to the module API (#10001)
Modules can now register sockets/pipe to the Redis main thread event loop and do network operations asynchronously. Previously, modules had to maintain an event loop and another thread for asynchronous network operations.

Also, if a module is calling API functions after doing some network operations, it had to synchronize its event loop thread's access with Redis main thread by locking the GIL, causing contention on the lock. After this commit, no synchronization is needed as module can operate in Redis main thread context. So, this commit may improve the performance for some use cases.

Added three functions to the module API:

* RedisModule_EventLoopAdd(int fd, int mask, RedisModuleEventLoopFunc func, void *user_data)
* RedisModule_EventLoopDel(int fd, int mask)
* RedisModule_EventLoopAddOneShot(RedisModuleEventLoopOneShotFunc func, void *user_data) - This function can be called from other threads to trigger callback on Redis main thread. Callback will be triggered only once. If Redis main thread is sleeping, this call will wake up the Redis main thread.
Event loop callbacks are called by Redis main thread after locking the GIL. Inside callbacks, modules can operate as if they are holding the GIL.

Added REDISMODULE_EVENT_EVENTLOOP event with two subevents:

* REDISMODULE_SUBEVENT_EVENTLOOP_BEFORE_SLEEP
* REDISMODULE_SUBEVENT_EVENTLOOP_AFTER_SLEEP

These events are for modules that want to participate in the before and after sleep action. e.g It might be useful to implement batching : Read data from the network, write all to a file in one go on BEFORE_SLEEP event.
2022-01-18 13:10:07 +02:00
Meir Shpilraien (Spielrein)
51f9bed3dd
Fix FUNCTION LOAD ignores unknown parameter. (#10131)
Following discussion on: https://github.com/redis/redis/issues/9899#issuecomment-1014689385
Raise error if unknows parameter is given to `FUNCTION LOAD`.

Before the fix:
```
127.0.0.1:6379> function load LUA lib2 foo bar "local function test1() return 5 end redis.register_function('test1', test1)"
OK
```

After the fix:
```
127.0.0.1:6379> function load LUA lib2 foo bar "local function test1() return 5 end redis.register_function('test1', test1)"
(error) ERR Unkowns option given: foo
```
2022-01-18 10:29:52 +02:00
Oran Agra
ae89958972
Set repl-diskless-sync to yes by default, add repl-diskless-sync-max-replicas (#10092)
1. enable diskless replication by default
2. add a new config named repl-diskless-sync-max-replicas that enables
   replication to start before the full repl-diskless-sync-delay was
   reached.
3. put replica online sooner on the master (see below)
4. test suite uses repl-diskless-sync-delay of 0 to be faster
5. a few tests that use multiple replica on a pre-populated master, are
   now using the new repl-diskless-sync-max-replicas
6. fix possible timing issues in a few cluster tests (see below)

put replica online sooner on the master 
----------------------------------------------------
there were two tests that failed because they needed for the master to
realize that the replica is online, but the test code was actually only
waiting for the replica to realize it's online, and in diskless it could
have been before the master realized it.

changes include two things:
1. the tests wait on the right thing
2. issues in the master, putting the replica online in two steps.

the master used to put the replica as online in 2 steps. the first
step was to mark it as online, and the second step was to enable the
write event (only after getting ACK), but in fact the first step didn't
contains some of the tasks to put it online (like updating good slave
count, and sending the module event). this meant that if a test was
waiting to see that the replica is online form the point of view of the
master, and then confirm that the module got an event, or that the
master has enough good replicas, it could fail due to timing issues.

so now the full effect of putting the replica online, happens at once,
and only the part about enabling the writes is delayed till the ACK.

fix cluster tests 
--------------------
I added some code to wait for the replica to sync and avoid race
conditions.
later realized the sentinel and cluster tests where using the original 5
seconds delay, so changed it to 0.

this means the other changes are probably not needed, but i suppose
they're still better (avoid race conditions)
2022-01-17 14:11:11 +02:00
zhaozhao.zz
90916f16a5
show subcommands latencystats (#10103)
since `info commandstats` already shows sub-commands, we should do the same in `info latencystats`.
similarly, the LATENCY HISTOGRAM command now shows sub-commands (with their full name) when:
* asking for all commands
* asking for a specific container command
* asking for a specific sub-command)

Co-authored-by: Oran Agra <oran@redislabs.com>
2022-01-17 12:32:32 +02:00
Binbin
26ef5132a6
Fix timing issue in PSETEX/PEXPIRE sub-second expire tests (#10121)
These two tests have a high probability of failure
on MacOS. Or it takes many retries to succeed.
Keys often expire before we can access them.

So this time we try to avoid this by reducing the time
of the first `after`, or removeing the first `after`.

The results of doing `20/81` and `0/101` are:
- PEXPIRE (20/81): 1069/1949
- PEXPIREAT (20/81): 1093/1949

- PEXPIRE (0/101): 31936 / 31936
- PEXPIREAT (0/101): 31936 / 31936

The first number is the number of times that the
test succeeded without any retries.
The second number is the total number of executions.

And we can see that `0/101` doesn't even need an extra
retries. Also reduces the time required for testing.
So in the end we chose `0/100`, i.e. remove the first `after`.

As for `PEXPIREAT`, there is no failure, but we still changed
it together, using `0/201`, after 2W tests, none of them failed.
2022-01-17 10:42:13 +02:00
sundb
32e7b46a17
Fix quicklist node not being recompressed correctly after inserting a new node before or after it (#10120)
### Describe
Fix crash found by CI, Introduced by #9849.
When we do any operation on the quicklist, we should make sure that all nodes
of the quicklist should not be in the recompressed state.

### Issues
This PR fixes two issues with incorrect recompression.
1. The current quicklist node is full and the previous node isn't full,
    the current node is not recompressed correctly after inserting elements into the previous node.
2. The current quicklist node is full and the next node isn't full,
    the current node is not recompressed correctly after inserting elements into the next node.

### Test
Add two tests to cover incorrect compression issues.

### Other
Fix unittest test failure caused by assertion introduced by #9849.
2022-01-16 08:54:40 +02:00
Meir Shpilraien (Spielrein)
4db4b43417
Function Flags support (no-writes, no-cluster, allow-state, allow-oom) (#10066)
# Redis Functions Flags

Following the discussion on #10025 Added Functions Flags support.
The PR is divided to 2 sections:
* Add named argument support to `redis.register_function` API.
* Add support for function flags

## `redis.register_function` named argument support

The first part of the PR adds support for named argument on `redis.register_function`, example:
```
redis.register_function{
    function_name='f1',
    callback=function()
        return 'hello'
    end,
    description='some desc'
}
```

The positional arguments is also kept, which means that it still possible to write:
```
redis.register_function('f1', function() return 'hello' end)
```

But notice that it is no longer possible to pass the optional description argument on the positional
argument version. Positional argument was change to allow passing only the mandatory arguments
(function name and callback). To pass more arguments the user must use the named argument version.

As with positional arguments, the `function_name` and `callback` is mandatory and an error will be
raise if those are missing. Also, an error will be raise if an unknown argument name is given or the
arguments type is wrong.

Tests was added to verify the new syntax.

## Functions Flags

The second part of the PR is adding functions flags support.
Flags are given to Redis when the engine calls `functionLibCreateFunction`, supported flags are:

* `no-writes` - indicating the function perform no writes which means that it is OK to run it on:
   * read-only replica
   * Using FCALL_RO
   * If disk error detected
   
   It will not be possible to run a function in those situations unless the function turns on the `no-writes` flag

* `allow-oom` - indicate that its OK to run the function even if Redis is in OOM state, if the function will
  not turn on this flag it will not be possible to run it if OOM reached (even if the function declares `no-writes`
  and even if `fcall_ro` is used). If this flag is set, any command will be allow on OOM (even those that is
  marked with CMD_DENYOOM). The assumption is that this flag is for advance users that knows its
  meaning and understand what they are doing, and Redis trust them to not increase the memory usage.
  (e.g. it could be an INCR or a modification on an existing key, or a DEL command)

* `allow-state` - indicate that its OK to run the function on stale replica, in this case we will also make
  sure the function is only perform `stale` commands and raise an error if not.

* `no-cluster` - indicate to disallow running the function if cluster is enabled.

Default behaviure of functions (if no flags is given):
1. Allow functions to read and write
2. Do not run functions on OOM
3. Do not run functions on stale replica
4. Allow functions on cluster

### Lua API for functions flags

On Lua engine, it is possible to give functions flags as `flags` named argument:

```
redis.register_function{function_name='f1', callback=function() return 1 end, flags={'no-writes', 'allow-oom'}, description='description'}
```

The function flags argument must be a Lua table that contains all the requested flags, The following
will result in an error:
* Unknown flag
* Wrong flag type

Default behaviour is the same as if no flags are used.

Tests were added to verify all flags functionality

## Additional changes
* mark FCALL and FCALL_RO with CMD_STALE flag (unlike EVAL), so that they can run if the function was
  registered with the `allow-stale` flag.
* Verify `CMD_STALE` on `scriptCall` (`redis.call`), so it will not be possible to call commands from script while
  stale unless the command is marked with the `CMD_STALE` flags. so that even if the function is allowed while
  stale we do not allow it to bypass the `CMD_STALE` flag of commands.
* Flags section was added to `FUNCTION LIST` command to provide the set of flags for each function:
```
> FUNCTION list withcode
1)  1) "library_name"
    2) "test"
    3) "engine"
    4) "LUA"
    5) "description"
    6) (nil)
    7) "functions"
    8) 1) 1) "name"
          2) "f1"
          3) "description"
          4) (nil)
          5) "flags"
          6) (empty array)
    9) "library_code"
   10) "redis.register_function{function_name='f1', callback=function() return 1 end}"
```
* Added API to get Redis version from within a script, The redis version can be provided using:
   1. `redis.REDIS_VERSION` - string representation of the redis version in the format of MAJOR.MINOR.PATH
   2. `redis.REDIS_VERSION_NUM` - number representation of the redis version in the format of `0x00MMmmpp`
      (`MM` - major, `mm` - minor,  `pp` - patch). The number version can be used to check if version is greater or less 
      another version. The string version can be used to return to the user or print as logs.

   This new API is provided to eval scripts and functions, it also possible to use this API during functions loading phase.
2022-01-14 14:02:02 +02:00
Binbin
56a802057e
Fix kill aof rewrite child test (#10107)
The dbs doesn't have any keys, `rdb-key-save-delay`
config has no effect that cause the rewrite to complete.

It was introduced in #10015.
2022-01-13 12:38:41 +02:00
Ozan Tezcan
f41cc87088
Added RM_MonotonicMicroseconds() API to provide monotonic time function (#10101)
Added RM_MonotonicMicroseconds(). Modules can use monotonic timestamp counter for measurements.
2022-01-13 11:36:03 +02:00
chenyang8094
e9bff7978a
Always create base AOF file when redis start from empty. (#10102)
Force create a BASE file (use a foreground `rewriteAppendOnlyFile`) when redis starts from an
empty data set and  `appendonly` is  yes.

The reasoning is that normally, after redis is running for some time, and the AOF has gone though
a few rewrites, there's always a base rdb file. and the scenario where the base file is missing, is
kinda rare (happens only at empty startup), so this change normalizes it.
But more importantly, there are or could be some complex modules that are started with some
configuration, when they create persistence they write that configuration to RDB AUX fields, so
that can can always know with which configuration the persistence file they're loading was
created (could be critical). there is (was) one scenario in which they could load their persisted data,
and that configuration was missing, and this change fixes it.

Add a new module event: REDISMODULE_SUBEVENT_PERSISTENCE_SYNC_AOF_START, similar to
REDISMODULE_SUBEVENT_PERSISTENCE_AOF_START which is async.

Co-authored-by: Oran Agra <oran@redislabs.com>
2022-01-13 08:49:26 +02:00
Binbin
20c33fe6a8
Show subcommand full name in error log / ACL LOG (#10105)
Use `getFullCommandName` to get the full name of the command.
It can also get the full name of the subcommand, like "script|help".

Before:
```
> SCRIPT HELP
(error) NOPERM this user has no permissions to run the 'help' command or its subcommand

> ACL LOG
    7) "object"
    8) "help"
```

After:
```
> SCRIPT HELP
(error) NOPERM this user has no permissions to run the 'script|help' command

> ACL LOG
    7) "object"
    8) "script|help"
```

Fix #10094
2022-01-12 20:05:14 +02:00
Binbin
e22146b07a
Add script tests to cover keys with expiration time set (#10096)
This commit adds some tests that the test cases will
access the keys with expiration time set in the script call.
There was no test case for this part before. See #10080

Also there is a test will cover #1525. we block the time so
that the key can not expire in the middle of the script execution.

Other changes:
1. Delete `evalTimeSnapshot` and just use `scriptTimeSnapshot` in it's place.
2. Some cleanups to scripting.tcl.
3. better names for tests that run in a loop to make them distinctable
2022-01-11 22:43:18 +02:00
Oran Agra
3204a03574
Move doc metadata from COMMAND to COMMAND DOCS (#10056)
Syntax:
`COMMAND DOCS [<command name> ...]`

Background:
Apparently old version of hiredis (and thus also redis-cli) can't
support more than 7 levels of multi-bulk nesting.

The solution is to move all the doc related metadata from COMMAND to a
new COMMAND DOCS sub-command.

The new DOCS sub-command returns a map of commands (not an array like in COMMAND),
And the same goes for the `subcommands` field inside it (also contains a map)

Besides that, the remaining new fields of COMMAND (hints, key-specs, and
sub-commands), are placed in the outer array rather than a nested map.
this was done mainly for consistency with the old format.

Other changes:
---
* Allow COMMAND INFO with no arguments, which returns all commands, so that we can some day deprecated
  the plain COMMAND (no args)

* Reduce the amount of deferred replies from both COMMAND and COMMAND
  DOCS, especially in the inner loops, since these create many small
  reply objects, which lead to many small write syscalls and many small
  TCP packets.
  To make this easier, when populating the command table, we count the
  history, args, and hints so we later know their size in advance.
  Additionally, the movablekeys flag was moved into the flags register.
* Update generate-commands-json.py to take the data from both command, it
  now executes redis-cli directly, instead of taking input from stdin.
* Sub-commands in both COMMAND (and COMMAND INFO), and also COMMAND DOCS,
  show their full name. i.e. CONFIG 
*   GET will be shown as `config|get` rather than just `get`.
  This will be visible both when asking for `COMMAND INFO config` and COMMAND INFO config|get`, but is
  especially important for the later.
  i.e. imagine someone doing `COMMAND INFO slowlog|get config|get` not being able to distinguish between the two
  items in the array response.
2022-01-11 17:16:16 +02:00
Binbin
39feee8e3a
LPOP/RPOP with count against non existing list return null array (#10095)
It used to return `$-1` in RESP2, now we will return `*-1`.
This is a bug in redis 6.2 when COUNT was added, the `COUNT`
option was introduced in #8179. Fix #10089.

the documentation of [LPOP](https://redis.io/commands/lpop) says
```
When called without the count argument:
Bulk string reply: the value of the first element, or nil when key does not exist.

When called with the count argument:
Array reply: list of popped elements, or nil when key does not exist.
```
2022-01-11 14:26:13 +02:00
Madelyn Olson
e8e02f900c
Changed latency histogram output to omit trailing 0s and periods (#10075)
Changed latency percentile output to omit trailing 0s and periods
2022-01-09 17:04:18 -08:00
Binbin
a84c964d37
Fix crash when error [sub]command name contains | (#10082)
The following error commands will crash redis-server:
```
> get|
Error: Server closed the connection
> get|set
Error: Server closed the connection
> get|other
```

The reason is in #9504, we use `lookupCommandBySds` for find the
container command. And it split the command (argv[0]) with `|`.
If we input something like `get|other`, after the split, `get`
will become a valid command name, pass the `ERR unknown command`
check, and finally crash in `addReplySubcommandSyntaxError`

In this case we do not need to split the command name with `|`
and just look in the commands dict to find if `argv[0]` is a
container command.

So this commit introduce a new function call `isContainerCommandBySds`
that it will return true if a command name is a container command.

Also with the old code, there is a incorrect error message:
```
> config|get set
(error) ERR Unknown subcommand or wrong number of arguments for 'set'. Try CONFIG|GET HELP.
```

The crash was reported in #10070.
2022-01-09 13:06:51 +02:00
guybe7
7cd6a64d2f
lpGetInteger returns int64_t, avoid overflow (#10068)
Fix #9410

Crucial for the ms and sequence deltas, but I changed all
calls, just in case (e.g. "flags")

Before this commit:
`ms_delta` and `seq_delta` could have overflown, causing `currid` to be wrong,
which in turn would cause `streamTrim` to trim the entire rax node (see new test)
2022-01-07 15:31:05 +02:00
Meir Shpilraien (Spielrein)
885f6b5ceb
Redis Function Libraries (#10004)
# Redis Function Libraries

This PR implements Redis Functions Libraries as describe on: https://github.com/redis/redis/issues/9906.

Libraries purpose is to provide a better code sharing between functions by allowing to create multiple
functions in a single command. Functions that were created together can safely share code between
each other without worrying about compatibility issues and versioning.

Creating a new library is done using 'FUNCTION LOAD' command (full API is described below)

This PR introduces a new struct called libraryInfo, libraryInfo holds information about a library:
* name - name of the library
* engine - engine used to create the library
* code - library code
* description - library description
* functions - the functions exposed by the library

When Redis gets the `FUNCTION LOAD` command it creates a new empty libraryInfo.
Redis passes the `CODE` to the relevant engine alongside the empty libraryInfo.
As a result, the engine will create one or more functions by calling 'libraryCreateFunction'.
The new funcion will be added to the newly created libraryInfo. So far Everything is happening
locally on the libraryInfo so it is easy to abort the operation (in case of an error) by simply
freeing the libraryInfo. After the library info is fully constructed we start the joining phase by
which we will join the new library to the other libraries currently exist on Redis.
The joining phase make sure there is no function collision and add the library to the
librariesCtx (renamed from functionCtx). LibrariesCtx is used all around the code in the exact
same way as functionCtx was used (with respect to RDB loading, replicatio, ...).
The only difference is that apart from function dictionary (maps function name to functionInfo
object), the librariesCtx contains also a libraries dictionary that maps library name to libraryInfo object.

## New API
### FUNCTION LOAD
`FUNCTION LOAD <ENGINE> <LIBRARY NAME> [REPLACE] [DESCRIPTION <DESCRIPTION>] <CODE>`
Create a new library with the given parameters:
* ENGINE - REPLACE Engine name to use to create the library.
* LIBRARY NAME - The new library name.
* REPLACE - If the library already exists, replace it.
* DESCRIPTION - Library description.
* CODE - Library code.

Return "OK" on success, or error on the following cases:
* Library name already taken and REPLACE was not used
* Name collision with another existing library (even if replace was uses)
* Library registration failed by the engine (usually compilation error)

## Changed API
### FUNCTION LIST
`FUNCTION LIST [LIBRARYNAME <LIBRARY NAME PATTERN>] [WITHCODE]`
Command was modified to also allow getting libraries code (so `FUNCTION INFO` command is no longer
needed and removed). In addition the command gets an option argument, `LIBRARYNAME` allows you to
only get libraries that match the given `LIBRARYNAME` pattern. By default, it returns all libraries.

### INFO MEMORY
Added number of libraries to `INFO MEMORY`

### Commands flags
`DENYOOM` flag was set on `FUNCTION LOAD` and `FUNCTION RESTORE`. We consider those commands
as commands that add new data to the dateset (functions are data) and so we want to disallows
to run those commands on OOM.

## Removed API
* FUNCTION CREATE - Decided on https://github.com/redis/redis/issues/9906
* FUNCTION INFO - Decided on https://github.com/redis/redis/issues/9899

## Lua engine changes
When the Lua engine gets the code given on `FUNCTION LOAD` command, it immediately runs it, we call
this run the loading run. Loading run is not a usual script run, it is not possible to invoke any
Redis command from within the load run.
Instead there is a new API provided by `library` object. The new API's: 
* `redis.log` - behave the same as `redis.log`
* `redis.register_function` - register a new function to the library

The loading run purpose is to register functions using the new `redis.register_function` API.
Any attempt to use any other API will result in an error. In addition, the load run is has a time
limit of 500ms, error is raise on timeout and the entire operation is aborted.

### `redis.register_function`
`redis.register_function(<function_name>, <callback>, [<description>])`
This new API allows users to register a new function that will be linked to the newly created library.
This API can only be called during the load run (see definition above). Any attempt to use it outside
of the load run will result in an error.
The parameters pass to the API are:
* function_name - Function name (must be a Lua string)
* callback - Lua function object that will be called when the function is invokes using fcall/fcall_ro
* description - Function description, optional (must be a Lua string).

### Example
The following example creates a library called `lib` with 2 functions, `f1` and `f1`, returns 1 and 2 respectively:
```
local function f1(keys, args)
    return 1
end

local function f2(keys, args)
    return 2
end

redis.register_function('f1', f1)
redis.register_function('f2', f2)
```

Notice: Unlike `eval`, functions inside a library get the KEYS and ARGV as arguments to the
functions and not as global.

### Technical Details

On the load run we only want the user to be able to call a white list on API's. This way, in
the future, if new API's will be added, the new API's will not be available to the load run
unless specifically added to this white list. We put the while list on the `library` object and
make sure the `library` object is only available to the load run by using [lua_setfenv](https://www.lua.org/manual/5.1/manual.html#lua_setfenv) API. This API allows us to set
the `globals` of a function (and all the function it creates). Before starting the load run we
create a new fresh Lua table (call it `g`) that only contains the `library` API (we make sure
to set global protection on this table just like the general global protection already exists
today), then we use [lua_setfenv](https://www.lua.org/manual/5.1/manual.html#lua_setfenv)
to set `g` as the global table of the load run. After the load run finished we update `g`
metatable and set `__index` and `__newindex` functions to be `_G` (Lua default globals),
we also pop out the `library` object as we do not need it anymore.
This way, any function that was created on the load run (and will be invoke using `fcall`) will
see the default globals as it expected to see them and will not have the `library` API anymore.

An important outcome of this new approach is that now we can achieve a distinct global table
for each library (it is not yet like that but it is very easy to achieve it now). In the future we can
decide to remove global protection because global on different libraries will not collide or we
can chose to give different API to different libraries base on some configuration or input.

Notice that this technique was meant to prevent errors and was not meant to prevent malicious
user from exploit it. For example, the load run can still save the `library` object on some local
variable and then using in `fcall` context. To prevent such a malicious use, the C code also make
sure it is running in the right context and if not raise an error.
2022-01-06 13:39:38 +02:00