feat: replace grpc with fibp binary protocol

[vieiralucas]

Summary

• Replace entire gRPC transport layer with Fila's custom binary protocol (FIBP) per docs/protocol.md
• New fibp/ package: codec for all 42 opcodes, frame reader/writer with continuation support, encoding primitives
• New connection manager with request/response multiplexing, server-push delivery routing, keepalive
• Added admin operations (CreateQueue, DeleteQueue, GetStats, ListQueues, SetConfig, GetConfig, ListConfig, Redrive)
• Added auth management (CreateApiKey, RevokeApiKey, ListApiKeys, SetAcl, GetAcl)
• Added batch operations (AckMany, NackMany)
• All 18 FIBP error codes mapped to sentinel errors
• Removed gRPC/protobuf dependencies — zero external dependencies (stdlib only)
• Net -3,008 lines, 28 tests passing

Test plan

• go vet ./... passes
• go test ./... — 28 tests pass (14 codec, 14 client)
• Unit tests cover: all encoding primitives, frame round-trips, continuation frames, all opcode encode/decode, connection lifecycle, enqueue (direct + accumulator), consume streaming, ack, nack, error handling, admin ops, auth ops, leader redirect
• Integration tests against running fila-server (requires binary)
• CI workflow passes

🤖 Generated with Claude Code

---

Summary by cubic

Replaced gRPC with the Fila Binary Protocol (FIBP) to cut transport overhead and drop external deps. Adds a TCP connection manager, a full opcode codec, admin/auth APIs, and hardens consume/encoding paths.

• New Features

  • New fibp/ package: codec for 42 opcodes, frame reader/writer with continuation, and encoding primitives.
  • TCP connection manager: request/response multiplexing, server-push routing for Consume, keepalive, and leader-hint redirect.
  • Hot path over FIBP: Enqueue, Consume, Ack, Nack; plus AckMany and NackMany. Accumulator modes (Auto/Linger/Disabled) preserved.
  • Admin and auth APIs: Create/DeleteQueue, GetStats, ListQueues, Set/Get/ListConfig, Redrive; Create/Revoke/List API keys, Set/Get ACL.
  • Maps all FIBP error codes to sentinel errors for errors.Is checks. Zero external dependencies (stdlib only).

• Bug Fixes

  • Consume cleanup: cancel no longer closes the delivery channel; read-loop cleanup runs in defer; waiter notifications are non-blocking; leader redirect is bounded to one hop.
  • Accumulator uses context.Background for batch RPCs to avoid one caller’s cancellation canceling the whole batch.
  • Decode functions validate item counts to prevent large allocations; FrameWriter errors when maxFrameSize is too small.
  • Tests strengthened for TLS validation and leader-redirect behavior.

^{Written for commit 334d5b4. Summary will update on new commits.}

[cubic-dev-ai]

9 issues found across 30 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="conn.go">

<violation number="1" location="conn.go:146">
P1: When `ctx.Done()` triggers inside delivery forwarding, `readLoop` returns without running waiter/delivery cleanup.</violation>

<violation number="2" location="conn.go:206">
P1: `closeWaiters` can deadlock by blocking on a full waiter channel during shutdown.</violation>

<violation number="3" location="conn.go:210">
P0: `cancelConsume` can close a delivery channel while `readLoop` is sending to it, which can panic with `send on closed channel`.</violation>
</file>

<file name="client_test.go">

<violation number="1" location="client_test.go:385">
P2: `TestNotLeaderRedirect` only asserts non-nil error, so it can pass on unrelated failures instead of verifying `ProtocolError` redirect metadata.</violation>

<violation number="2" location="client_test.go:429">
P3: `TestTLSClientCertWithoutTLS` is a false-positive-prone test because it accepts any dial error from `localhost:0` instead of asserting the specific option-validation failure.</violation>
</file>

<file name="consume.go">

<violation number="1" location="consume.go:79">
P1: Leader redirect handling is unbounded recursive, despite the API promising a single retry.</violation>
</file>

<file name="fibp/frame.go">

<violation number="1" location="fibp/frame.go:34">
P2: Do not force `maxBody` to 1 when `maxFrameSize` is too small; return an error instead. The current logic can write frames larger than `maxFrameSize`.</violation>
</file>

<file name="accumulator.go">

<violation number="1" location="accumulator.go:197">
P1: The batch request uses the first item's context, so one caller's context cancellation (e.g. timeout) will fail the entire batch. Consider deriving a merged context or using `context.Background()` with a deadline from the longest-lived item, so that one caller's cancellation does not cascade to all other callers in the same batch.</violation>
</file>

<file name="fibp/decode.go">

<violation number="1" location="fibp/decode.go:49">
P2: Validate `count` before allocating the results slice. As written, a malformed frame can set `count` to a huge value and force large allocations/DoS before decode errors are raised.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}