blob: 85340c380da2de2ed8e63102c26696a31a03dab0 [file] [log] [blame]
* Copyright (c) 2020 The WebRTC project authors. All Rights Reserved.
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
#include <stddef.h>
#include <stdint.h>
#include <string>
#include <utility>
#include "absl/strings/string_view.h"
#include "rtc_base/bit_buffer.h"
#include "rtc_base/checks.h"
#include "rtc_base/constructor_magic.h"
namespace webrtc {
// Wrap BitBufferWriter and extend its functionality by (1) keeping track of
// the number of bits written and (2) owning its buffer.
class BitWriter final {
explicit BitWriter(size_t byte_count)
: buffer_(byte_count, '\0'),
bit_writer_(reinterpret_cast<uint8_t*>(&buffer_[0]), buffer_.size()),
valid_(true) {
RTC_DCHECK_GT(byte_count, 0);
void WriteBits(uint64_t val, size_t bit_count);
void WriteBits(absl::string_view input);
// Returns everything that was written so far.
// Nothing more may be written after this is called.
std::string GetString();
std::string buffer_;
rtc::BitBufferWriter bit_writer_;
// Note: Counting bits instead of bytes wraps around earlier than it has to,
// which means the maximum length is lower than it could be. We don't expect
// to go anywhere near the limit, though, so this is good enough.
size_t written_bits_;
bool valid_;
} // namespace webrtc