Buffers

Capy’s buffer system enables efficient I/O operations through lightweight memory views, scatter/gather I/O, and growable storage containers.

Overview

Buffers are the foundation of all I/O in Capy. They represent regions of memory that can be read from or written to, enabling zero-copy data transfer and platform-agnostic I/O algorithms.

Quick Example

#include <boost/capy/buffers.hpp>
#include <boost/capy/buffers/make_buffer.hpp>
#include <boost/capy/read.hpp>
#include <boost/capy/write.hpp>

using namespace boost::capy;

task<void> echo(ReadStream auto& in, WriteStream auto& out)
{
    char buffer[4096];
    for (;;)
    {
        auto [ec1, n] = co_await in.read_some(make_buffer(buffer));
        if (ec1 == cond::eof)
            break;
        if (ec1.failed())
            co_return;

        auto [ec2, _] = co_await write(out, make_buffer(buffer, n));
        if (ec2.failed())
            co_return;
    }
}

Topics

Topic Description

Buffers and I/O

Why buffers exist and how they enable efficient I/O

Buffer Types

const_buffer, mutable_buffer, and make_buffer

Buffer Sequences

Scatter/gather I/O with multiple buffers

Buffer Algorithms

buffer_copy, buffer_size, buffer_empty

Dynamic Buffers

Growable buffers with producer/consumer model

Key Types

Type Purpose

const_buffer

Read-only view of contiguous bytes

mutable_buffer

Writable view of contiguous bytes

flat_dynamic_buffer

Growable contiguous buffer

circular_dynamic_buffer

Ring buffer for streaming

string_dynamic_buffer

Adapter for std::string

vector_dynamic_buffer

Adapter for std::vector<unsigned char>

Key Concepts

Concept Description

ConstBufferSequence

Range of read-only buffers

MutableBufferSequence

Range of writable buffers

DynamicBuffer

Resizable buffer with prepare/commit semantics

DynamicBufferParam

Safe parameter passing for coroutines

Headers

Header Contents

<boost/capy/buffers.hpp>

Core buffer types and concepts

<boost/capy/buffers/make_buffer.hpp>

make_buffer helper function

<boost/capy/buffers/buffer_copy.hpp>

buffer_copy algorithm

<boost/capy/buffers/consuming_buffers.hpp>

Incremental buffer consumption

<boost/capy/buffers/flat_dynamic_buffer.hpp>

Contiguous dynamic buffer

<boost/capy/buffers/circular_dynamic_buffer.hpp>

Ring buffer implementation

<boost/capy/buffers/string_dynamic_buffer.hpp>

String adapter

<boost/capy/buffers/vector_dynamic_buffer.hpp>

Vector adapter

Navigation

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