transmission/libtransmission/torrent-magnet.h

85 lines
2.1 KiB
C++

// This file Copyright © Mnemosyne LLC.
// It may be used under GPLv2 (SPDX: GPL-2.0-only), GPLv3 (SPDX: GPL-3.0-only),
// or any future license endorsed by Mnemosyne LLC.
// License text can be found in the licenses/ folder.
#pragma once
#ifndef __TRANSMISSION__
#error only libtransmission should #include this header.
#endif
#include <cstddef> // size_t
#include <cstdint> // int64_t
#include <ctime> // time_t
#include <deque>
#include <limits>
#include <memory>
#include <optional>
#include <string>
#include <string_view>
#include <vector>
#include <small/vector.hpp>
#include "libtransmission/tr-macros.h"
// defined by BEP #9
inline constexpr auto MetadataPieceSize = 1024 * 16;
using tr_metadata_piece = small::max_size_vector<std::byte, MetadataPieceSize>;
class tr_metadata_download
{
public:
tr_metadata_download(std::string_view log_name, int64_t size);
[[nodiscard]] static constexpr auto is_valid_metadata_size(int64_t const size) noexcept
{
return size > 0 && size <= std::numeric_limits<int>::max();
}
[[nodiscard]] auto is_complete() const noexcept
{
return std::empty(pieces_needed_);
}
void set_metadata_piece(int64_t piece, void const* data, size_t len);
[[nodiscard]] std::optional<int64_t> get_next_metadata_request(time_t now) noexcept;
[[nodiscard]] double get_metadata_percent() const noexcept;
[[nodiscard]] constexpr auto const& get_metadata() const noexcept
{
return metadata_;
}
[[nodiscard]] TR_CONSTEXPR20 std::string_view log_name() const noexcept
{
return log_name_;
}
private:
struct metadata_node
{
time_t requested_at = {};
int64_t piece = {};
};
[[nodiscard]] constexpr size_t get_piece_length(int64_t const piece) const noexcept
{
return piece + 1 == piece_count_ ? // last piece
std::size(metadata_) - (piece * MetadataPieceSize) :
MetadataPieceSize;
}
void create_all_needed(int64_t n_pieces) noexcept;
std::vector<char> metadata_;
std::deque<metadata_node> pieces_needed_;
int64_t piece_count_ = {};
std::string log_name_;
};