components/variations/active_field_trials.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "components/variations/active_field_trials.h"
   6
   7 #include <vector>
   8
   9 #include "base/strings/stringprintf.h"
  10 #include "base/strings/utf_string_conversions.h"
  11 #include "components/variations/metrics_util.h"
  12
  13 namespace variations {
  14
  15 namespace {
  16
  17 // Populates |name_group_ids| based on |active_groups|.
  18 void GetFieldTrialActiveGroupIdsForActiveGroups(
  19     const base::FieldTrial::ActiveGroups& active_groups,
  20     std::vector<ActiveGroupId>* name_group_ids) {
  21   DCHECK(name_group_ids->empty());
  22   for (base::FieldTrial::ActiveGroups::const_iterator it =
  23        active_groups.begin(); it != active_groups.end(); ++it) {
  24     name_group_ids->push_back(MakeActiveGroupId(it->trial_name,
  25                                                 it->group_name));
  26   }
  27 }
  28
  29 }  // namespace
  30
  31 ActiveGroupId MakeActiveGroupId(const std::string& trial_name,
  32                                 const std::string& group_name) {
  33   ActiveGroupId id;
  34   id.name = metrics::HashName(trial_name);
  35   id.group = metrics::HashName(group_name);
  36   return id;
  37 }
  38
  39 void GetFieldTrialActiveGroupIds(
  40     std::vector<ActiveGroupId>* name_group_ids) {
  41   DCHECK(name_group_ids->empty());
  42   // A note on thread safety: Since GetActiveFieldTrialGroups() is thread
  43   // safe, and we operate on a separate list of that data, this function is
  44   // technically thread safe as well, with respect to the FieldTrialList data.
  45   base::FieldTrial::ActiveGroups active_groups;
  46   base::FieldTrialList::GetActiveFieldTrialGroups(&active_groups);
  47   GetFieldTrialActiveGroupIdsForActiveGroups(active_groups,
  48                                              name_group_ids);
  49 }
  50
  51 void GetFieldTrialActiveGroupIdsAsStrings(std::vector<std::string>* output) {
  52   DCHECK(output->empty());
  53   std::vector<ActiveGroupId> name_group_ids;
  54   GetFieldTrialActiveGroupIds(&name_group_ids);
  55   for (size_t i = 0; i < name_group_ids.size(); ++i) {
  56     output->push_back(base::StringPrintf(
  57         "%x-%x", name_group_ids[i].name, name_group_ids[i].group));
  58   }
  59 }
  60
  61 namespace testing {
  62
  63 void TestGetFieldTrialActiveGroupIds(
  64     const base::FieldTrial::ActiveGroups& active_groups,
  65     std::vector<ActiveGroupId>* name_group_ids) {
  66   GetFieldTrialActiveGroupIdsForActiveGroups(active_groups,
  67                                              name_group_ids);
  68 }
  69
  70 }  // namespace testing
  71
  72 }  // namespace variations