Meir Shpilraien (Spielrein) 2237131e15
Unified Lua and modules reply parsing and added RESP3 support to RM_Call (#9202)
## Current state
1. Lua has its own parser that handles parsing `reds.call` replies and translates them
  to Lua objects that can be used by the user Lua code. The parser partially handles
  resp3 (missing big number, verbatim, attribute, ...)
2. Modules have their own parser that handles parsing `RM_Call` replies and translates
  them to RedisModuleCallReply objects. The parser does not support resp3.

In addition, in the future, we want to add Redis Function (#8693) that will probably
support more languages. At some point maintaining so many parsers will stop
scaling (bug fixes and protocol changes will need to be applied on all of them).
We will probably end up with different parsers that support different parts of the
resp protocol (like we already have today with Lua and modules)

## PR Changes
This PR attempt to unified the reply parsing of Lua and modules (and in the future
Redis Function) by introducing a new parser unit (`resp_parser.c`). The new parser
handles parsing the reply and calls different callbacks to allow the users (another
unit that uses the parser, i.e, Lua, modules, or Redis Function) to analyze the reply.

### Lua API Additions
The code that handles reply parsing on `scripting.c` was removed. Instead, it uses
the resp_parser to parse and create a Lua object out of the reply. As mentioned
above the Lua parser did not handle parsing big numbers, verbatim, and attribute.
The new parser can handle those and so Lua also gets it for free.
Those are translated to Lua objects in the following way:
1. Big Number - Lua table `{'big_number':'<str representation for big number>'}`
2. Verbatim - Lua table `{'verbatim_string':{'format':'<verbatim format>', 'string':'<verbatim string value>'}}`
3. Attribute - currently ignored and not expose to the Lua parser, another issue will be open to decide how to expose it.

Tests were added to check resp3 reply parsing on Lua

### Modules API Additions
The reply parsing code on `module.c` was also removed and the new resp_parser is used instead.
In addition, the RedisModuleCallReply was also extracted to a separate unit located on `call_reply.c`
(in the future, this unit will also be used by Redis Function). A nice side effect of unified parsing is
that modules now also support resp3. Resp3 can be enabled by giving `3` as a parameter to the
fmt argument of `RM_Call`. It is also possible to give `0`, which will indicate an auto mode. i.e, Redis
will automatically chose the reply protocol base on the current client set on the RedisModuleCtx
(this mode will mostly be used when the module want to pass the reply to the client as is).
In addition, the following RedisModuleAPI were added to allow analyzing resp3 replies:

* New RedisModuleCallReply types:
   * `REDISMODULE_REPLY_MAP`
   * `REDISMODULE_REPLY_SET`
   * `REDISMODULE_REPLY_BOOL`
   * `REDISMODULE_REPLY_DOUBLE`
   * `REDISMODULE_REPLY_BIG_NUMBER`
   * `REDISMODULE_REPLY_VERBATIM_STRING`
   * `REDISMODULE_REPLY_ATTRIBUTE`

* New RedisModuleAPI:
   * `RedisModule_CallReplyDouble` - getting double value from resp3 double reply
   * `RedisModule_CallReplyBool` - getting boolean value from resp3 boolean reply
   * `RedisModule_CallReplyBigNumber` - getting big number value from resp3 big number reply
   * `RedisModule_CallReplyVerbatim` - getting format and value from resp3 verbatim reply
   * `RedisModule_CallReplySetElement` - getting element from resp3 set reply
   * `RedisModule_CallReplyMapElement` - getting key and value from resp3 map reply
   * `RedisModule_CallReplyAttribute` - getting a reply attribute
   * `RedisModule_CallReplyAttributeElement` - getting key and value from resp3 attribute reply
   
* New context flags:
   * `REDISMODULE_CTX_FLAGS_RESP3` - indicate that the client is using resp3

Tests were added to check the new RedisModuleAPI

### Modules API Changes
* RM_ReplyWithCallReply might return REDISMODULE_ERR if the given CallReply is in resp3
  but the client expects resp2. This is not a breaking change because in order to get a resp3
  CallReply one needs to specifically specify `3` as a parameter to the fmt argument of
  `RM_Call` (as mentioned above).

Tests were added to check this change

### More small Additions
* Added `debug set-disable-deny-scripts` that allows to turn on and off the commands no-script
flag protection. This is used by the Lua resp3 tests so it will be possible to run `debug protocol`
and check the resp3 parsing code.

Co-authored-by: Oran Agra <oran@redislabs.com>
Co-authored-by: Yossi Gottlieb <yossigo@gmail.com>
2021-08-04 16:28:07 +03:00
..
2021-07-30 10:00:07 +03:00

Redis Test Suite

The normal execution mode of the test suite involves starting and manipulating local redis-server instances, inspecting process state, log files, etc.

The test suite also supports execution against an external server, which is enabled using the --host and --port parameters. When executing against an external server, tests tagged external:skip are skipped.

There are additional runtime options that can further adjust the test suite to match different external server configurations:

Option Impact
--singledb Only use database 0, don't assume others are supported.
--ignore-encoding Skip all checks for specific encoding.
--ignore-digest Skip key value digest validations.
--cluster-mode Run in strict Redis Cluster compatibility mode.

Tags

Tags are applied to tests to classify them according to the subsystem they test, but also to indicate compatibility with different run modes and required capabilities.

Tags can be applied in different context levels:

  • start_server context
  • tags context that bundles several tests together
  • A single test context.

The following compatibility and capability tags are currently used:

Tag Indicates
external:skip Not compatible with external servers.
cluster:skip Not compatible with --cluster-mode.
needs:repl Uses replication and needs to be able to SYNC from server.
needs:debug Uses the DEBUG command or other debugging focused commands (like OBJECT).
needs:pfdebug Uses the PFDEBUG command.
needs:config-maxmemory Uses CONFIG SET to manipulate memory limit, eviction policies, etc.
needs:config-resetstat Uses CONFIG RESETSTAT to reset statistics.
needs:reset Uses RESET to reset client connections.
needs:save Uses SAVE to create an RDB file.

When using an external server (--host and --port), filtering using the external:skip tags is done automatically.

When using --cluster-mode, filtering using the cluster:skip tag is done automatically.

In addition, it is possible to specify additional configuration. For example, to run tests on a server that does not permit SYNC use:

./runtest --host <host> --port <port> --tags -needs:repl