1 files changed, 61 insertions, 0 deletions
diff --git a/third_party/libwebrtc/logging/rtc_event_log/encoder/bit_writer.h b/third_party/libwebrtc/logging/rtc_event_log/encoder/bit_writer.h
new file mode 100644
index 0000000000..421e7c4370
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+++ b/third_party/libwebrtc/logging/rtc_event_log/encoder/bit_writer.h
@@ -0,0 +1,61 @@
+/*
+ *  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.
+ */
+
+#ifndef LOGGING_RTC_EVENT_LOG_ENCODER_BIT_WRITER_H_
+#define LOGGING_RTC_EVENT_LOG_ENCODER_BIT_WRITER_H_
+
+#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"
+
+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 {
+ public:
+  explicit BitWriter(size_t byte_count)
+      : buffer_(byte_count, '\0'),
+        bit_writer_(reinterpret_cast<uint8_t*>(&buffer_[0]), buffer_.size()),
+        written_bits_(0),
+        valid_(true) {
+    RTC_DCHECK_GT(byte_count, 0);
+  }
+
+  BitWriter(const BitWriter&) = delete;
+  BitWriter& operator=(const BitWriter&) = delete;
+
+  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();
+
+ private:
+  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
+
+#endif  // LOGGING_RTC_EVENT_LOG_ENCODER_BIT_WRITER_H_