transmission/libtransmission/block-info.cc

75 lines
2.0 KiB
C++

// This file Copyright © 2007-2022 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 "transmission.h"
#include "block-info.h"
#include "tr-assert.h"
void tr_block_info::initSizes(uint64_t total_size_in, uint32_t piece_size_in) noexcept
{
TR_ASSERT(piece_size_in == 0 || piece_size_in >= BlockSize);
if (piece_size_in == 0)
{
*this = {};
return;
}
total_size_ = total_size_in;
piece_size_ = piece_size_in;
n_pieces_ = (total_size_ + piece_size_ - 1) / piece_size_;
n_blocks_ = (total_size_ + BlockSize - 1) / BlockSize;
uint32_t remainder = total_size_ % piece_size_;
final_piece_size_ = remainder != 0U ? remainder : piece_size_;
remainder = total_size_ % BlockSize;
final_block_size_ = remainder != 0U ? remainder : BlockSize;
}
tr_block_info::Location tr_block_info::byteLoc(uint64_t byte_idx) const noexcept
{
TR_ASSERT(byte_idx <= totalSize());
if (!isInitialized())
{
return {};
}
auto loc = Location{};
loc.byte = byte_idx;
if (byte_idx == totalSize()) // handle 0-byte files at the end of a torrent
{
loc.block = blockCount() - 1;
loc.piece = pieceCount() - 1;
}
else
{
loc.block = byte_idx / BlockSize;
loc.piece = byte_idx / pieceSize();
}
loc.block_offset = static_cast<uint32_t>(loc.byte - (uint64_t{ loc.block } * BlockSize));
loc.piece_offset = static_cast<uint32_t>(loc.byte - (uint64_t{ loc.piece } * pieceSize()));
return loc;
}
tr_block_info::Location tr_block_info::blockLoc(tr_block_index_t block) const noexcept
{
TR_ASSERT(block < blockCount());
return byteLoc(uint64_t{ block } * BlockSize);
}
tr_block_info::Location tr_block_info::pieceLoc(tr_piece_index_t piece, uint32_t offset, uint32_t length) const noexcept
{
TR_ASSERT(piece < pieceCount());
return byteLoc(uint64_t{ piece } * pieceSize() + offset + length);
}