1 // Copyright 2017 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/variations_id_collection.h"
6 
7 #include "base/bind_helpers.h"
8 #include "base/feature_list.h"
9 #include "base/metrics/field_trial_params.h"
10 #include "base/stl_util.h"
11 #include "base/time/time.h"
12 #include "components/variations/active_field_trials.h"
13 
14 namespace variations {
15 
VariationsIdCollection(IDCollectionKey collection_key,base::RepeatingCallback<void (VariationID)> new_id_callback)16 VariationsIdCollection::VariationsIdCollection(
17     IDCollectionKey collection_key,
18     base::RepeatingCallback<void(VariationID)> new_id_callback)
19     : collection_key_(collection_key) {
20   base::FieldTrialList::AddObserver(this);
21 
22   base::FieldTrial::ActiveGroups initial_groups;
23   base::FieldTrialList::GetActiveFieldTrialGroups(&initial_groups);
24   for (const base::FieldTrial::ActiveGroup& group : initial_groups) {
25     OnFieldTrialGroupFinalized(group.trial_name, group.group_name);
26   }
27 
28   // Delay setting |new_id_callback_| until initialization is over.
29   new_id_callback_ = new_id_callback;
30 }
31 
~VariationsIdCollection()32 VariationsIdCollection::~VariationsIdCollection() {
33   base::FieldTrialList::RemoveObserver(this);
34 }
35 
OnFieldTrialGroupFinalized(const std::string & trial_name,const std::string & group_name)36 void VariationsIdCollection::OnFieldTrialGroupFinalized(
37     const std::string& trial_name,
38     const std::string& group_name) {
39   const VariationID id =
40       GetGoogleVariationID(collection_key_, trial_name, group_name);
41   if (id != EMPTY_ID) {
42     bool modified = id_set_.insert(id).second;
43     if (modified && new_id_callback_)
44       new_id_callback_.Run(id);
45   }
46 }
47 
GetIds()48 const std::set<VariationID>& VariationsIdCollection::GetIds() {
49   return id_set_;
50 }
51 
52 }  // namespace variations
53