chromium/third_party/webrtc/logging/rtc_event_log/events/rtc_event_field_encoding_parser.h

/*
 *  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.
 */

#ifndef LOGGING_RTC_EVENT_LOG_EVENTS_RTC_EVENT_FIELD_ENCODING_PARSER_H_
#define LOGGING_RTC_EVENT_LOG_EVENTS_RTC_EVENT_FIELD_ENCODING_PARSER_H_

#include <cstddef>
#include <cstdint>
#include <string>
#include <type_traits>
#include <vector>

#include "absl/base/attributes.h"
#include "absl/strings/string_view.h"
#include "absl/types/optional.h"
#include "api/array_view.h"
#include "api/units/timestamp.h"
#include "logging/rtc_event_log/events/fixed_length_encoding_parameters_v3.h"
#include "logging/rtc_event_log/events/rtc_event_field_encoding.h"
#include "logging/rtc_event_log/events/rtc_event_field_extraction.h"
#include "logging/rtc_event_log/events/rtc_event_log_parse_status.h"
#include "rtc_base/checks.h"

namespace webrtc {

class EventParser { … };

// Inverse of the ExtractRtcEventMember function used when parsing
// a log. Uses a vector of values to populate a specific field in a
// vector of structs.
template <typename T,
          typename E,
          std::enable_if_t<std::is_integral<T>::value, bool> = true>
ABSL_MUST_USE_RESULT RtcEventLogParseStatus
PopulateRtcEventMember(const rtc::ArrayView<uint64_t> values,
                       T E::*member,
                       rtc::ArrayView<E> output) { … }

// Same as above, but for optional fields.
template <typename T,
          typename E,
          std::enable_if_t<std::is_integral<T>::value, bool> = true>
ABSL_MUST_USE_RESULT RtcEventLogParseStatus
PopulateRtcEventMember(const rtc::ArrayView<uint8_t> positions,
                       const rtc::ArrayView<uint64_t> values,
                       absl::optional<T> E::*member,
                       rtc::ArrayView<E> output) { … }

// Same as above, but for enum fields.
template <typename T,
          typename E,
          std::enable_if_t<std::is_enum<T>::value, bool> = true>
ABSL_MUST_USE_RESULT RtcEventLogParseStatus
PopulateRtcEventMember(const rtc::ArrayView<uint64_t> values,
                       T E::*member,
                       rtc::ArrayView<E> output) { … }

// Same as above, but for string fields.
template <typename E>
ABSL_MUST_USE_RESULT RtcEventLogParseStatus
PopulateRtcEventMember(const rtc::ArrayView<absl::string_view> values,
                       std::string E::*member,
                       rtc::ArrayView<E> output) { … }

// Same as above, but for Timestamp fields.
// N.B. Assumes that the encoded value uses millisecond precision.
template <typename E>
ABSL_MUST_USE_RESULT RtcEventLogParseStatus
PopulateRtcEventTimestamp(const rtc::ArrayView<uint64_t>& values,
                          Timestamp E::*timestamp,
                          rtc::ArrayView<E> output) { … }

template <typename E>
rtc::ArrayView<E> ExtendLoggedBatch(std::vector<E>& output,
                                    size_t new_elements) { … }

}  // namespace webrtc
#endif  // LOGGING_RTC_EVENT_LOG_EVENTS_RTC_EVENT_FIELD_ENCODING_PARSER_H_