tdlight/td/telegram/files/FileBitmask.cpp
Arseny Smirnov 3b238f6fba Files streaming
GitOrigin-RevId: 78df1cd44c95380cd4af46f4db809ce28876db1f
2018-11-11 15:38:04 +04:00

85 lines
2.1 KiB
C++

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