| andresp@webrtc.org | a36ad69 | 2014-05-14 12:24:04 +0000 | [diff] [blame^] | 1 | // |
| 2 | // Copyright (c) 2014 The WebRTC project authors. All Rights Reserved. |
| 3 | // |
| 4 | // Use of this source code is governed by a BSD-style license |
| 5 | // that can be found in the LICENSE file in the root of the source |
| 6 | // tree. An additional intellectual property rights grant can be found |
| 7 | // in the file PATENTS. All contributing project authors may |
| 8 | // be found in the AUTHORS file in the root of the source tree. |
| 9 | // |
| 10 | |
| 11 | #ifndef WEBRTC_SYSTEM_WRAPPERS_INTERFACE_FIELD_TRIAL_H_ |
| 12 | #define WEBRTC_SYSTEM_WRAPPERS_INTERFACE_FIELD_TRIAL_H_ |
| 13 | |
| 14 | #include <string> |
| 15 | |
| 16 | #include "webrtc/common_types.h" |
| 17 | |
| 18 | // Field trials allow webrtc clients (such as Chrome) to turn on feature code |
| 19 | // in binaries out in the field and gather information with that. |
| 20 | // |
| 21 | // WebRTC clients MUST provide an implementation of: |
| 22 | // |
| 23 | // std::string webrtc::field_trial::FindFullName(const std::string& trial). |
| 24 | // |
| 25 | // Or link with a default one provided in: |
| 26 | // |
| 27 | // system_wrappers/source/system_wrappers.gyp:field_trial_default |
| 28 | // |
| 29 | // |
| 30 | // They are designed to wire up directly to chrome field trials and to speed up |
| 31 | // developers by reducing the need to wire APIs to control whether a feature is |
| 32 | // on/off. E.g. to experiment with a new method that could lead to a different |
| 33 | // trade-off between CPU/bandwidth: |
| 34 | // |
| 35 | // 1 - Develop the feature with default behaviour off: |
| 36 | // |
| 37 | // if (FieldTrial::FindFullName("WebRTCExperimenMethod2") == "Enabled") |
| 38 | // method2(); |
| 39 | // else |
| 40 | // method1(); |
| 41 | // |
| 42 | // 2 - Once the changes are rolled to chrome, the new code path can be |
| 43 | // controlled as normal chrome field trials. |
| 44 | // |
| 45 | // 3 - Evaluate the new feature and clean the code paths. |
| 46 | // |
| 47 | // Notes: |
| 48 | // - NOT every feature is a candidate to be controlled by this mechanism as |
| 49 | // it may require negotation between involved parties (e.g. SDP). |
| 50 | // |
| 51 | // TODO(andresp): since chrome --force-fieldtrials does not marks the trial |
| 52 | // as active it does not gets propaged to renderer process. For now one |
| 53 | // needs to push a config with start_active:true or run a local finch |
| 54 | // server. |
| 55 | // |
| 56 | // TODO(andresp): support --force_fieldtirals from webrtc tests. |
| 57 | // TODO(andresp): find out how to get bots to run tests with trials enabled. |
| 58 | |
| 59 | namespace webrtc { |
| 60 | namespace field_trial { |
| 61 | |
| 62 | // Returns the group name chosen for the named trial, or the empty string |
| 63 | // if the trial does not exists. |
| 64 | // |
| 65 | // Note: To keep things tidy append all the trial names with WebRTC. |
| 66 | std::string FindFullName(const std::string& name); |
| 67 | |
| 68 | } // namespace field_trial |
| 69 | } // namespace webrtc |
| 70 | |
| 71 | #endif // WEBRTC_SYSTEM_WRAPPERS_INTERFACE_FIELD_TRIAL_H_ |