rtc_event_field_extraction.cc | Explore in Territory

/*
 *  Copyright (c) 2021 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 "logging/rtc_event_log/events/rtc_event_field_extraction.h"

#include <algorithm>
#include <cstdint>
#include <limits>

#include "rtc_base/checks.h"

namespace webrtc_event_logging {

// The bitwidth required to encode values in the range
// [0, `max_pos_magnitude`] using an unsigned representation.
uint8_t UnsignedBitWidth(uint64_t max_magnitude) { … }

// The bitwidth required to encode signed values in the range
// [-`max_neg_magnitude`, `max_pos_magnitude`] using a signed
// 2-complement representation.
uint8_t SignedBitWidth(uint64_t max_pos_magnitude, uint64_t max_neg_magnitude) { … }

// Return the maximum integer of a given bit width.
uint64_t MaxUnsignedValueOfBitWidth(uint64_t bit_width) { … }

// Computes the delta between `previous` and `current`, under the assumption
// that `bit_mask` is the largest value before wrap-around occurs. The bitmask
// must be of the form 2^x-1. (We use the wrap-around to more efficiently
// compress counters that wrap around at different bit widths than the
// backing C++ data type.)
uint64_t UnsignedDelta(uint64_t previous, uint64_t current, uint64_t bit_mask) { … }

}  // namespace webrtc_event_logging
chromium/third_party/webrtc/logging/rtc_event_log/events/rtc_event_field_extraction.cc
