transmission/libtransmission/makemeta.h

244 lines
5.9 KiB
C++

// This file Copyright © 2007-2023 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
#include <algorithm> // std::move
#include <cstddef> // std::byte
#include <cstdint>
#include <future>
#include <string>
#include <string_view>
#include <utility> // std::pair
#include <vector>
#include "transmission.h"
#include "announce-list.h"
#include "block-info.h"
#include "file.h"
#include "torrent-files.h"
#include "utils.h" // for tr_saveFile()
class tr_metainfo_builder
{
public:
explicit tr_metainfo_builder(std::string_view single_file_or_parent_directory);
tr_metainfo_builder(tr_metainfo_builder&&) = delete;
tr_metainfo_builder(tr_metainfo_builder const&) = delete;
tr_metainfo_builder& operator=(tr_metainfo_builder&&) = delete;
tr_metainfo_builder& operator=(tr_metainfo_builder const&) = delete;
// Generate piece checksums asynchronously.
// - This must be done before calling `benc()` or `save()`.
// - Runs in a worker thread because it can be time-consuming.
// - Can be cancelled with `cancelChecksums()` and polled with `checksumStatus()`
// - Resolves with a `tr_error*` which is set on failure or nullptr on success.
std::future<tr_error*> makeChecksums()
{
return std::async(
std::launch::async,
[this]()
{
tr_error* error = nullptr;
blockingMakeChecksums(&error);
return error;
});
}
// Returns the status of a `makeChecksums()` call:
// The current piece being tested and the total number of pieces in the torrent.
[[nodiscard]] constexpr std::pair<tr_piece_index_t, tr_piece_index_t> checksumStatus() const noexcept
{
return std::make_pair(checksum_piece_, block_info_.pieceCount());
}
// Tell the `makeChecksums()` worker thread to cleanly exit ASAP.
constexpr void cancelChecksums() noexcept
{
cancel_ = true;
}
// generate the metainfo
[[nodiscard]] std::string benc(tr_error** error = nullptr) const;
// generate the metainfo and save it to a torrent file
bool save(std::string_view filename, tr_error** error = nullptr) const
{
return tr_saveFile(filename, benc(error), error);
}
/// setters
void setAnnounceList(tr_announce_list announce)
{
announce_ = std::move(announce);
}
// whether or not to include User-Agent and creation time
constexpr void setAnonymize(bool anonymize) noexcept
{
anonymize_ = anonymize;
}
void setComment(std::string_view comment)
{
comment_ = comment;
}
bool setPieceSize(uint32_t piece_size) noexcept;
constexpr void setPrivate(bool is_private) noexcept
{
is_private_ = is_private;
}
void setSource(std::string_view source)
{
source_ = source;
}
void setWebseeds(std::vector<std::string> webseeds)
{
webseeds_ = std::move(webseeds);
}
/// getters
[[nodiscard]] constexpr auto const& announceList() const noexcept
{
return announce_;
}
[[nodiscard]] constexpr auto const& anonymize() const noexcept
{
return anonymize_;
}
[[nodiscard]] constexpr auto const& comment() const noexcept
{
return comment_;
}
[[nodiscard]] TR_CONSTEXPR20 auto fileCount() const noexcept
{
return files_.fileCount();
}
[[nodiscard]] TR_CONSTEXPR20 auto fileSize(tr_file_index_t i) const noexcept
{
return files_.fileSize(i);
}
[[nodiscard]] constexpr auto const& isPrivate() const noexcept
{
return is_private_;
}
[[nodiscard]] auto name() const noexcept
{
return tr_sys_path_basename(top_);
}
[[nodiscard]] auto const& path(tr_file_index_t i) const noexcept
{
return files_.path(i);
}
[[nodiscard]] constexpr auto pieceSize() const noexcept
{
return block_info_.pieceSize();
}
[[nodiscard]] constexpr auto pieceCount() const noexcept
{
return block_info_.pieceCount();
}
[[nodiscard]] constexpr auto const& source() const noexcept
{
return source_;
}
[[nodiscard]] constexpr auto const& top() const noexcept
{
return top_;
}
[[nodiscard]] constexpr auto totalSize() const noexcept
{
return files_.totalSize();
}
[[nodiscard]] constexpr auto const& webseeds() const noexcept
{
return webseeds_;
}
///
[[nodiscard]] constexpr static uint32_t defaultPieceSize(uint64_t total_size) noexcept
{
uint32_t const KiB = 1024;
uint32_t const MiB = 1048576;
uint32_t const GiB = 1073741824;
if (total_size >= 2 * GiB)
{
return 2 * MiB;
}
if (total_size >= 1 * GiB)
{
return 1 * MiB;
}
if (total_size >= 512 * MiB)
{
return 512 * KiB;
}
if (total_size >= 350 * MiB)
{
return 256 * KiB;
}
if (total_size >= 150 * MiB)
{
return 128 * KiB;
}
if (total_size >= 50 * MiB)
{
return 64 * KiB;
}
return 32 * KiB; /* less than 50 meg */
}
// must be a power of two and >= 16 KiB
[[nodiscard]] static bool isLegalPieceSize(uint32_t x);
private:
bool blockingMakeChecksums(tr_error** error = nullptr);
std::string top_;
tr_torrent_files files_;
tr_announce_list announce_;
tr_block_info block_info_;
std::vector<std::byte> piece_hashes_;
std::vector<std::string> webseeds_;
std::string comment_;
std::string source_;
tr_piece_index_t checksum_piece_ = 0;
bool is_private_ = false;
bool anonymize_ = false;
bool cancel_ = false;
};