perf(net): add opt-in buffered stream reads

[thweetkomputer]

Large incoming payloads can already span several queued receive buffers, but TcpStream::ReadSome returns only the front buffer. Add opt-in ReadSomeBuffered(span<byte>) so callers with a larger destination can consume the queued bytes in one await, bounded by the destination size. It waits only for initial data and returns as soon as the available queue drains. Existing ReadSome behavior and receive-pool sizing remain unchanged.

The new API preserves partial-buffer offsets, byte order, and EOF semantics. If a later buffer view fails after bytes were consumed, it returns the valid prefix and reports the error on the next read. TLS keeps its existing decrypted-read behavior. Public API comments explain caller responsibility for scheduling fairness.

Validation: Debug build with GCC 13; all five standalone CTest checks passed. CI passed all eight combinations of amd64/arm64, Clang/GCC Debug, and kernel-bypass OFF/ON, plus clang-format. The CI artifact confirms the real multishot receive and EOF assertions pass without the provided-buffer fallback. The new check uses deterministic queued backend views for cross-buffer ordering, partial reads, unchanged ordinary reads, and error handling, plus real Unix socket receives for initial waiting, prompt short reads, and EOF. This host rejects io_uring provided-buffer-ring setup with EINVAL, so live socket checks use the runtime's existing one-shot fallback; live multishot batching performance was not measured.

The EOF fixture tests queued data plus EOF deterministically, then checks real socket EOF after consuming the sent payload. This avoids the older Linux AF_UNIX multishot lost-EOF wakeup race triggered by back-to-back send and shutdown, while preserving coverage of data-before-EOF ordering. Assertions flush their output so any CI timeout identifies the last completed check.

cmake -S . -B build -G Ninja -DCMAKE_C_COMPILER=gcc-13 -DCMAKE_CXX_COMPILER=g++-13 -DCMAKE_BUILD_TYPE=Debug -DBYCORF_BUILD_EXAMPLES=OFF
cmake --build build --target bycorf_tcp_buffered_read_check bycorf_connect_timer_check bycorf_connection_storage_check bycorf_backend_selection_check bycorf_task_transfer_check --parallel 4
ctest --test-dir build --output-on-failure --no-tests=error

[coderabbitai]

Important

• 🔍 Trigger review

This repository does not receive automatic reviews because it has fewer than 10 stars.

⚙️ Run configuration

• Configuration used: Organization UI
• Review profile: CHILL
• Plan: Advanced
• Run ID: 53a555e6-e5d8-4d3c-8f11-3cdc2f47a165

• Autofix · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}