libhttpserver/src/httpserver/detail/io_completion_storage.hpp at v3 · etr/libhttpserver

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This file is part of libhttpserver

SPDX-License-Identifier: LGPL-2.1-or-later

#if !defined(HTTPSERVER_COMPILATION)

#error "io_completion_storage.hpp is internal."

#endif

#ifndef SRC_HTTPSERVER_DETAIL_IO_COMPLETION_STORAGE_HPP_

#define SRC_HTTPSERVER_DETAIL_IO_COMPLETION_STORAGE_HPP_

#include <algorithm>

#include <cstddef>

#include <cstring>

#include <vector>

#include <httpserver/detail/io_operation.hpp>

namespace httpserver {

namespace detail {

// A kernel request owns its bytes until its completion packet, independently

// of the operation's logical lifetime. Bounded staging permits partial transfers

// and avoids narrowing size_t to Win32's ULONG or allocating multi-GB buffers.

class owned_completion_storage final {

public:

explicit owned_completion_storage(const op_state& op);

std::byte* data() noexcept { return bytes_.data(); }

std::size_t size() const noexcept { return bytes_.size(); }

// Never inspect the borrowed span after cancellation/release won. The

// backend serializes the claim and this copy before publishing success.

bool claim_read(op_state& op, std::size_t transferred) const;

private:

std::vector<std::byte> bytes_;

};

} // namespace detail

} // namespace httpserver

#endif // SRC_HTTPSERVER_DETAIL_IO_COMPLETION_STORAGE_HPP_