feat(command): rate limiting with gcra command

[ndyakov]

This PR introduces GCRA command for rate limiting.

marked as draft/ work in progress until an image with the command is available for testing.

---

Note

Medium Risk
Introduces a new command type with custom reply parsing and integrates it into cluster routing/value extraction; mistakes could cause incorrect parsing or behavior in pipelines/cluster mode.

Overview
Adds first-class support for Redis 8.8+ GCRA rate limiting, including a new RateLimitCmdable API (GCRA/GCRAWithArgs), GCRAArgs/GCRAResult types, and a dedicated GCRACmd with explicit 5-element reply decoding.

Wires the new command type into the generic command-value extraction and OSS cluster router value-setting paths, and adds both integration and unit tests plus a standalone example/gcra-rate-limiting module demonstrating basic, burst, and weighted token usage.

Also includes small whitespace/format-only touch-ups in TLS examples/tests and a mock pooler test.

^{Reviewed by Cursor Bugbot for commit 899776c. Bugbot is set up for automated code reviews on this repo. Configure here.}

[jit-ci]

🛡️ Jit Security Scan Results

✅ No security findings were detected in this PR

---

^{Security scan by Jit}

[ofekshenawa]

LGTM

[ndyakov]

I would prefer to merge other PRs and release a version before including this one (or any other 8.8 related changes) in master.

[cursor]

ReadInt used for RESP double fields in reply

High Severity

The Redis GCRA command returns reply_after and full_burst_after as RESP doubles (using addReplyDouble on the server side), but readReply uses rd.ReadInt() to parse them. The ReadInt method doesn't handle the RespFloat wire type, so it will always fail with a parse error when reaching the 4th element. Additionally, RetryAfter and FullBurstAfter in GCRAResult are typed int64 but need to be float64 to hold the double values returned by the server.

Additional Locations (1)

• ratelimit_commands.go#L47-L51

 

^{Reviewed by Cursor Bugbot for commit d443382. Configure here.}

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

There are 2 total unresolved issues (including 1 from previous review).

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, have a team admin enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit 899776c. Configure here.}

[cursor]

Zero-value Tokens causes unexpected Redis error

High Severity

The condition args.Tokens != 1 treats Go's zero-value (0) for the Tokens field as an explicit user choice, sending TOKENS 0 to Redis which rejects it as "out of range". When a user constructs GCRAArgs without setting Tokens, the field defaults to 0, not the documented default of 1. This means any caller of GCRAWithArgs that omits Tokens will get an unexpected error instead of the documented default behavior.

Additional Locations (1)

• ratelimit_commands.go#L27-L31

 

^{Reviewed by Cursor Bugbot for commit 899776c. Configure here.}