| // |
| // Copyright (c) 2014 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 WEBRTC_SYSTEM_WRAPPERS_INCLUDE_FIELD_TRIAL_H_ |
| #define WEBRTC_SYSTEM_WRAPPERS_INCLUDE_FIELD_TRIAL_H_ |
| |
| #include <string> |
| |
| // Field trials allow webrtc clients (such as Chrome) to turn on feature code |
| // in binaries out in the field and gather information with that. |
| // |
| // WebRTC clients MUST provide an implementation of: |
| // |
| // std::string webrtc::field_trial::FindFullName(const std::string& trial). |
| // |
| // Or link with a default one provided in: |
| // |
| // system_wrappers/system_wrappers.gyp:field_trial_default |
| // |
| // |
| // They are designed to wire up directly to chrome field trials and to speed up |
| // developers by reducing the need to wire APIs to control whether a feature is |
| // on/off. E.g. to experiment with a new method that could lead to a different |
| // trade-off between CPU/bandwidth: |
| // |
| // 1 - Develop the feature with default behaviour off: |
| // |
| // if (FieldTrial::FindFullName("WebRTCExperimenMethod2") == "Enabled") |
| // method2(); |
| // else |
| // method1(); |
| // |
| // 2 - Once the changes are rolled to chrome, the new code path can be |
| // controlled as normal chrome field trials. |
| // |
| // 3 - Evaluate the new feature and clean the code paths. |
| // |
| // Notes: |
| // - NOT every feature is a candidate to be controlled by this mechanism as |
| // it may require negotation between involved parties (e.g. SDP). |
| // |
| // TODO(andresp): since chrome --force-fieldtrials does not marks the trial |
| // as active it does not gets propaged to renderer process. For now one |
| // needs to push a config with start_active:true or run a local finch |
| // server. |
| // |
| // TODO(andresp): find out how to get bots to run tests with trials enabled. |
| |
| namespace webrtc { |
| namespace field_trial { |
| |
| // Returns the group name chosen for the named trial, or the empty string |
| // if the trial does not exists. |
| // |
| // Note: To keep things tidy append all the trial names with WebRTC. |
| std::string FindFullName(const std::string& name); |
| |
| // Convenience method, returns true iff FindFullName(name) return a string that |
| // starts with "Enabled". |
| // TODO(tommi): Make sure all implementations support this. |
| inline bool IsEnabled(const char* name) { |
| return FindFullName(name).find("Enabled") == 0; |
| } |
| |
| } // namespace field_trial |
| } // namespace webrtc |
| |
| #endif // WEBRTC_SYSTEM_WRAPPERS_INCLUDE_FIELD_TRIAL_H_ |
