transmission/libtransmission/file-piece-map.cc

172 lines
4.7 KiB
C++

// This file Copyright © 2021-2022 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.
#include <algorithm>
#include <vector>
#include "transmission.h"
#include "block-info.h"
#include "file-piece-map.h"
#include "torrent-metainfo.h"
#include "tr-assert.h"
void tr_file_piece_map::reset(tr_block_info const& block_info, uint64_t const* file_sizes, size_t n_files)
{
file_bytes_.resize(n_files);
file_bytes_.shrink_to_fit();
file_pieces_.resize(n_files);
file_pieces_.shrink_to_fit();
uint64_t offset = 0;
for (tr_file_index_t i = 0; i < n_files; ++i)
{
auto const file_size = file_sizes[i];
auto const begin_byte = offset;
auto const begin_piece = block_info.byteLoc(begin_byte).piece;
auto end_byte = tr_byte_index_t{};
auto end_piece = tr_piece_index_t{};
if (file_size != 0)
{
end_byte = offset + file_size;
auto const final_byte = end_byte - 1;
auto const final_piece = block_info.byteLoc(final_byte).piece;
end_piece = final_piece + 1;
}
else
{
end_byte = begin_byte;
// TODO(ckerr): should end_piece == begin_piece, same as _bytes are?
end_piece = begin_piece + 1;
}
file_pieces_[i] = piece_span_t{ begin_piece, end_piece };
file_bytes_[i] = byte_span_t{ begin_byte, end_byte };
offset += file_size;
}
}
void tr_file_piece_map::reset(tr_torrent_metainfo const& tm)
{
auto const n = tm.fileCount();
auto file_sizes = std::vector<uint64_t>(n);
for (tr_file_index_t i = 0; i < n; ++i)
{
file_sizes[i] = tm.fileSize(i);
}
reset({ tm.totalSize(), tm.pieceSize() }, std::data(file_sizes), std::size(file_sizes));
}
tr_file_piece_map::piece_span_t tr_file_piece_map::pieceSpan(tr_file_index_t file) const
{
return file_pieces_[file];
}
tr_file_piece_map::file_span_t tr_file_piece_map::fileSpan(tr_piece_index_t piece) const
{
auto compare = CompareToSpan<tr_piece_index_t>{};
auto const begin = std::begin(file_pieces_);
auto const& [equal_begin, equal_end] = std::equal_range(begin, std::end(file_pieces_), piece, compare);
return { tr_piece_index_t(std::distance(begin, equal_begin)), tr_piece_index_t(std::distance(begin, equal_end)) };
}
tr_file_piece_map::file_offset_t tr_file_piece_map::fileOffset(uint64_t offset) const
{
auto compare = CompareToSpan<uint64_t>{};
auto const begin = std::begin(file_bytes_);
auto const it = std::lower_bound(begin, std::end(file_bytes_), offset, compare);
tr_file_index_t const file_index = std::distance(begin, it);
auto const file_offset = offset - it->begin;
return file_offset_t{ file_index, file_offset };
}
/***
****
***/
tr_file_priorities::tr_file_priorities(tr_file_piece_map const* fpm)
{
reset(fpm);
}
void tr_file_priorities::reset(tr_file_piece_map const* fpm)
{
fpm_ = fpm;
auto const n = std::size(*fpm_);
priorities_.resize(n);
priorities_.shrink_to_fit();
std::fill_n(std::begin(priorities_), n, TR_PRI_NORMAL);
}
void tr_file_priorities::set(tr_file_index_t file, tr_priority_t priority)
{
priorities_[file] = priority;
}
void tr_file_priorities::set(tr_file_index_t const* files, size_t n, tr_priority_t priority)
{
for (size_t i = 0; i < n; ++i)
{
set(files[i], priority);
}
}
tr_priority_t tr_file_priorities::filePriority(tr_file_index_t file) const
{
TR_ASSERT(file < std::size(priorities_));
return priorities_[file];
}
tr_priority_t tr_file_priorities::piecePriority(tr_piece_index_t piece) const
{
auto const [begin_idx, end_idx] = fpm_->fileSpan(piece);
auto const begin = std::begin(priorities_) + begin_idx;
auto const end = std::begin(priorities_) + end_idx;
auto const it = std::max_element(begin, end);
if (it == end)
{
return TR_PRI_NORMAL;
}
return *it;
}
/***
****
***/
void tr_files_wanted::reset(tr_file_piece_map const* fpm)
{
fpm_ = fpm;
wanted_ = tr_bitfield{ std::size(*fpm) };
wanted_.setHasAll(); // by default we want all files
}
void tr_files_wanted::set(tr_file_index_t file, bool wanted)
{
wanted_.set(file, wanted);
}
void tr_files_wanted::set(tr_file_index_t const* files, size_t n, bool wanted)
{
for (size_t i = 0; i < n; ++i)
{
set(files[i], wanted);
}
}
bool tr_files_wanted::fileWanted(tr_file_index_t file) const
{
return wanted_.test(file);
}
bool tr_files_wanted::pieceWanted(tr_piece_index_t piece) const
{
auto const [begin, end] = fpm_->fileSpan(piece);
return wanted_.count(begin, end) != 0;
}