105 lines
2.5 KiB
C++
105 lines
2.5 KiB
C++
//
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// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2018
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//
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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//
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#include "td/telegram/files/FileBitmask.h"
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#include "td/utils/common.h"
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#include "td/utils/misc.h"
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namespace td {
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Bitmask::Bitmask(Decode, Slice data) : data_(zero_one_decode(data)) {
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}
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Bitmask::Bitmask(Ones, int64 count) : data_(narrow_cast<size_t>((count + 7) / 8), '\0') {
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for (int64 i = 0; i < count; i++) {
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set(i);
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}
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}
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std::string Bitmask::encode() const {
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// remove zeroes in the end to make encoding deterministic
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td::Slice data(data_);
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while (!data.empty() && data.back() == '\0') {
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data.remove_suffix(1);
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}
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return zero_one_encode(data);
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}
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int64 Bitmask::get_ready_prefix_size(int64 offset, int64 part_size, int64 file_size) const {
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if (offset < 0) {
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return 0;
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}
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auto offset_part = offset / part_size;
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auto ones = get_ready_parts(offset_part);
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if (ones == 0) {
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return 0;
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}
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auto ready_parts_end = (offset_part + ones) * part_size;
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if (file_size != 0 && ready_parts_end > file_size) {
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ready_parts_end = file_size;
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if (offset > file_size) {
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offset = file_size;
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}
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}
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auto res = ready_parts_end - offset;
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CHECK(res >= 0);
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return res;
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}
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int64 Bitmask::get_total_size(int64 part_size) const {
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int64 res = 0;
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for (int64 i = 0; i < size(); i++) {
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res += static_cast<int64>(get(i));
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}
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return res * part_size;
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}
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bool Bitmask::get(int64 offset_part) const {
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if (offset_part < 0) {
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return 0;
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}
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auto index = narrow_cast<size_t>(offset_part / 8);
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if (index >= data_.size()) {
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return 0;
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}
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return (static_cast<uint8>(data_[index]) & (1 << static_cast<int>(offset_part % 8))) != 0;
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}
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int64 Bitmask::get_ready_parts(int64 offset_part) const {
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int64 res = 0;
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while (get(offset_part + res)) {
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res++;
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}
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return res;
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}
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std::vector<int32> Bitmask::as_vector() const {
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std::vector<int32> res;
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auto size = narrow_cast<int32>(data_.size() * 8);
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for (int32 i = 0; i < size; i++) {
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if (get(i)) {
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res.push_back(i);
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}
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}
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return res;
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}
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void Bitmask::set(int64 offset_part) {
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CHECK(offset_part >= 0);
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auto need_size = narrow_cast<size_t>(offset_part / 8 + 1);
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if (need_size > data_.size()) {
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data_.resize(need_size, '\0');
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}
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data_[need_size - 1] |= (1 << (offset_part % 8));
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}
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int64 Bitmask::size() const {
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return static_cast<int64>(data_.size() * 8);
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}
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} // namespace td
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