blob: bf7a7cc62547a27b2a556eac84760adb5aefaa90 [file] [log] [blame]
* Copyright (c) 2022 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 <memory>
#include <string>
#include "absl/strings/string_view.h"
#include "api/field_trials_registry.h"
#include "rtc_base/containers/flat_map.h"
namespace webrtc {
// The FieldTrials class is used to inject field trials into webrtc.
// Field trials allow webrtc clients (such as Chromium) to turn on feature code
// in binaries out in the field and gather information with that.
// They are designed to be easy to use with Chromium field trials and to speed
// up developers by reducing the need to wire up APIs to control whether a
// feature is on/off.
// The field trials are injected into objects that use them at creation time.
// NOTE: Creating multiple FieldTrials-object is currently prohibited
// until we remove the global string (TODO(
// (unless using CreateNoGlobal):
class FieldTrials : public FieldTrialsRegistry {
explicit FieldTrials(const std::string& s);
// Create a FieldTrials object that is not reading/writing from
// global variable (i.e can not be used for all parts of webrtc).
static std::unique_ptr<FieldTrials> CreateNoGlobal(const std::string& s);
explicit FieldTrials(const std::string& s, bool);
std::string GetValue(absl::string_view key) const override;
const bool uses_global_;
const std::string field_trial_string_;
const char* const previous_field_trial_string_;
const flat_map<std::string, std::string> key_value_map_;
} // namespace webrtc