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 #include "webrtc/test/field_trial.h" 12 13 #include <algorithm> 14 #include <cassert> 15 #include <cstdio> 16 #include <cstdlib> 17 #include <map> 18 #include <string> 19 20 #include "webrtc/system_wrappers/interface/field_trial.h" 21 22 namespace webrtc { 23 namespace { 24 // Clients of this library have show a clear intent to setup field trials by 25 // linking with it. As so try to crash if they forget to call 26 // InitFieldTrialsFromString before webrtc tries to access a field trial. 27 bool field_trials_initiated_ = false; 28 std::map<std::string, std::string> field_trials_; 29 } // namespace 30 31 namespace field_trial { FindFullName(const std::string & trial_name)32std::string FindFullName(const std::string& trial_name) { 33 assert(field_trials_initiated_); 34 std::map<std::string, std::string>::const_iterator it = 35 field_trials_.find(trial_name); 36 if (it == field_trials_.end()) 37 return std::string(); 38 return it->second; 39 } 40 } // namespace field_trial 41 42 namespace test { 43 // Note: this code is copied from src/base/metrics/field_trial.cc since the aim 44 // is to mimic chromium --force-fieldtrials. InitFieldTrialsFromString(const std::string & trials_string)45void InitFieldTrialsFromString(const std::string& trials_string) { 46 static const char kPersistentStringSeparator = '/'; 47 48 // Catch an error if this is called more than once. 49 assert(field_trials_initiated_ == false); 50 field_trials_initiated_ = true; 51 52 if (trials_string.empty()) return; 53 54 size_t next_item = 0; 55 while (next_item < trials_string.length()) { 56 size_t name_end = trials_string.find(kPersistentStringSeparator, next_item); 57 if (name_end == trials_string.npos || next_item == name_end) 58 break; 59 size_t group_name_end = trials_string.find(kPersistentStringSeparator, 60 name_end + 1); 61 if (group_name_end == trials_string.npos || name_end + 1 == group_name_end) 62 break; 63 std::string name(trials_string, next_item, name_end - next_item); 64 std::string group_name(trials_string, name_end + 1, 65 group_name_end - name_end - 1); 66 next_item = group_name_end + 1; 67 68 // Fail if duplicate with different group name. 69 if (field_trials_.find(name) != field_trials_.end() && 70 field_trials_.find(name)->second != group_name) 71 break; 72 73 field_trials_[name] = group_name; 74 75 // Successfully parsed all field trials from the string. 76 if (next_item == trials_string.length()) 77 return; 78 } 79 // LOG does not prints when this is called early on main. 80 fprintf(stderr, "Invalid field trials string.\n"); 81 82 // Using abort so it crashs both in debug and release mode. 83 abort(); 84 } 85 } // namespace test 86 } // namespace webrtc 87