io_buffer_param is in Boost.Corosio

[vinniefalco]

Summary by CodeRabbit

• New Features

  • Added a type-erased io_buffer_param for efficient, zero-allocation buffer handling at I/O boundaries.

• Refactor

  • Updated stream, socket, and SSL implementations to accept the new buffer parameter for read/write operations.

• Tests

  • Added comprehensive unit tests covering many buffer types, sequences, zero-byte cases, and pass-by-value/reference scenarios.

• Documentation

  • Updated guide examples and includes to use the new buffer parameter.

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📥 Commits

Reviewing files that changed from the base of the PR and between 361750f and 9d462b9.

📒 Files selected for processing (13)

• doc/modules/ROOT/pages/guide/buffers.adoc
• include/boost/corosio/io_buffer_param.hpp
• include/boost/corosio/io_stream.hpp
• include/boost/corosio/read.hpp
• include/boost/corosio/socket.hpp
• include/boost/corosio/write.hpp
• src/corosio/src/detail/epoll/sockets.hpp
• src/corosio/src/detail/iocp/sockets.cpp
• src/corosio/src/detail/iocp/sockets.hpp
• src/corosio/src/test/mocket.cpp
• src/openssl/src/openssl_stream.cpp
• src/wolfssl/src/wolfssl_stream.cpp
• test/unit/io_buffer_param.cpp

📝 Walkthrough

Walkthrough

Adds a new type-erased buffer helper boost::corosio::io_buffer_param, replaces includes and all capy::buffer_param usages with io_buffer_param across public I/O interfaces, backends, encryption streams, tests, and docs.

Changes

Cohort / File(s)	Summary
New buffer parameter type include/boost/corosio/io_buffer_param.hpp	Adds boost::corosio::io_buffer_param: a zero-heap, type-erased buffer-sequence wrapper with a templated constructor and copy_to API; includes lifetime/safety docs and examples (+384/-0).
Public I/O interfaces include/boost/corosio/io_stream.hpp	Replaced include and changed virtual signatures: read_some/write_some now accept io_buffer_param instead of capy::buffer_param (+3/-3).
Header includes updated include/boost/corosio/read.hpp, include/boost/corosio/write.hpp, include/boost/corosio/socket.hpp	Switched include from boost/capy/buffers/buffer_param.hpp to boost/corosio/io_buffer_param.hpp (minor include edits).
Backend socket implementations src/corosio/src/detail/epoll/sockets.hpp, src/corosio/src/detail/iocp/sockets.hpp, src/corosio/src/detail/iocp/sockets.cpp	Updated read_some/write_some declarations and definitions to use io_buffer_param (signature changes only).
Encryption stream overrides src/openssl/src/openssl_stream.cpp, src/wolfssl/src/wolfssl_stream.cpp	Updated read_some/write_some override signatures to accept io_buffer_param (parameter-type changes only).
Test/mock updates src/corosio/src/test/mocket.cpp	Updated mock mocket_impl read_some/write_some overrides to use io_buffer_param (signature-only changes).
Unit tests test/unit/io_buffer_param.cpp	New comprehensive unit tests exercising io_buffer_param copy semantics across many buffer types, limits, and edge cases (+~442/-0).
Documentation doc/modules/ROOT/pages/guide/buffers.adoc	Updated heading, example signature, and include path to reference io_buffer_param and new header (+3/-3).

Sequence Diagram(s)

sequenceDiagram
  autonumber
  participant Caller as "Caller / Coroutine"
  participant IOStream as "boost::corosio::io_stream_impl"
  participant IOParam as "io_buffer_param"
  participant OS as "Platform IO (epoll/iocp/SSL)"

  Caller->>IOStream: call read_some(coroutine, exec, io_buffer_param, ...)
  IOStream->>IOParam: io_buffer_param.copy_to(dest, n)
  IOParam-->>IOStream: fills platform-native buffers (count)
  IOStream->>OS: submit read/write with native buffers
  OS-->>IOStream: completion (bytes, error)
  IOStream-->>Caller: resume coroutine with result

Loading

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~45 minutes

Possibly related PRs

• buffer_param usage tidying #42: Modifies the same read_some/write_some APIs and replaces buffer-parameter types across interfaces and backends.
• tests and more #34: Touches mocket_impl read/write overrides and related socket signature changes.

Poem

🐰 I found a tiny wrapper neat and trim,
It hops through calls both bright and prim,
No heap, just stacks and clever hops,
From streams to sockets it gently drops,
The rabbit cheers: "Buffers — trimmed to slim!"

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 12.50% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the primary change: moving/introducing io_buffer_param into the Boost.Corosio namespace, which is the core objective reflected across all modified files.

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[cppalliance-bot]

An automated preview of the documentation is available at https://43.corosio.prtest3.cppalliance.org/index.html

If more commits are pushed to the pull request, the docs will rebuild at the same URL.

2026-01-21 02:58:06 UTC

[coderabbitai]

Actionable comments posted: 2

🤖 Fix all issues with AI agents

In `@doc/modules/ROOT/pages/guide/buffers.adoc`:
- Around line 163-171: Update the section header to match the renamed type:
change the header text "buffer_param" to "io_buffer_param" so it aligns with the
code sample and description; look for the header line that currently reads "==
buffer_param" and replace it with "== io_buffer_param" to keep the doc
consistent with the io_buffer_param class shown in the example.

In `@test/unit/io_buffer_param.cpp`:
- Around line 403-408: The comment incorrectly says "temporary" while code
passes the lvalue arr to acceptByConstRef; either update the comment to reflect
that an lvalue is passed or change the call to pass an actual temporary to
exercise the temporary-conversion path (e.g., construct and pass a temporary
std::array<capy::const_buffer,2> inline instead of the arr variable). Ensure you
still create the two capy::const_buffer elements and assert via BOOST_TEST_EQ(n,
2) after calling acceptByConstRef to preserve the test intent.

🧹 Nitpick comments (3)

include/boost/corosio/read.hpp (1)

16-16: Same consideration as write.hpp regarding include necessity.

Similar to write.hpp, this file doesn't appear to use io_buffer_param directly. The type is used internally by io_stream::read_some. Consider removing if not needed for direct use.

include/boost/corosio/write.hpp (1)

16-16: Remove the redundant io_buffer_param.hpp include.

The io_buffer_param header is not directly used in this file—the write() function template uses ConstBufferSequence and consuming_buffers directly. Since io_stream.hpp (included on line 14) already includes io_buffer_param.hpp, this include is transitive and unnecessary. Removing it reduces header coupling and makes the dependency chain explicit.

test/unit/io_buffer_param.cpp (1)

24-37: Consider a tiny helper to reduce repeated copy_to assertions.

The copy-to-assert pattern is repeated across many tests; a small helper (e.g., assert_copy_to(...)) would reduce duplication and make future changes easier.