1 // Copyright 2013 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 "chrome/browser/history/most_visited_tiles_experiment.h"
6
7 #include "base/metrics/field_trial.h"
8 #include "base/metrics/histogram.h"
9 #include "base/strings/string_util.h"
10 #include "chrome/common/instant_types.h"
11
12 namespace history {
13
14 namespace {
15
16 // Constants for the most visited tile placement field trial.
17 // ex:
18 // "OneEightGroup_Flipped" --> Will cause tile 1 and 8 to be flipped.
19 // "OneEightGroup_NoChange" --> Will not flip anything.
20 //
21 // See field trial config (MostVisitedTilePlacement.json) for details.
22 const char kMostVisitedFieldTrialName[] = "MostVisitedTilePlacement";
23 // Name of histogram tracking types of actions carried out by the field trial.
24 const char kMostVisitedExperimentHistogramName[] =
25 "NewTabPage.MostVisitedTilePlacementExperiment";
26 const char kOneEightGroupPrefix[] = "OneEight";
27 const char kOneFourGroupPrefix[] = "OneFour";
28 const char kFlippedSuffix[] = "Flipped";
29 const char kDontShowOpenURLsGroupName[] = "DontShowOpenTabs";
30 // Minimum number of Most Visited suggestions required in order for the Most
31 // Visited Field Trial to remove a URL already open in the browser.
32 const size_t kMinUrlSuggestions = 8;
33
34 } // namespace
35
36 // static
MaybeShuffle(MostVisitedURLList * data)37 void MostVisitedTilesExperiment::MaybeShuffle(MostVisitedURLList* data) {
38 const std::string group_name =
39 base::FieldTrialList::FindFullName(kMostVisitedFieldTrialName);
40
41 // Depending on the study group of the client, we might flip the 1st and 4th
42 // tiles, or the 1st and 8th, or do nothing.
43 if (!EndsWith(group_name, kFlippedSuffix, true))
44 return;
45
46 size_t index_to_flip = 0;
47 if (StartsWithASCII(group_name, kOneEightGroupPrefix, true)) {
48 if (data->size() < 8) {
49 LogInHistogram(NTP_TILE_EXPERIMENT_ACTION_TOO_FEW_URLS_TILES_1_8);
50 return;
51 }
52 index_to_flip = 7;
53 } else if (StartsWithASCII(group_name, kOneFourGroupPrefix, true)) {
54 if (data->size() < 4) {
55 LogInHistogram(NTP_TILE_EXPERIMENT_ACTION_TOO_FEW_URLS_TILES_1_4);
56 return;
57 }
58 index_to_flip = 3;
59 }
60 std::swap((*data)[0], (*data)[index_to_flip]);
61 }
62
63 // static
IsDontShowOpenURLsEnabled()64 bool MostVisitedTilesExperiment::IsDontShowOpenURLsEnabled() {
65 return base::FieldTrialList::FindFullName(kMostVisitedFieldTrialName) ==
66 kDontShowOpenURLsGroupName;
67 }
68
69 // static
RemoveItemsMatchingOpenTabs(const std::set<std::string> & open_urls,std::vector<InstantMostVisitedItem> * items)70 void MostVisitedTilesExperiment::RemoveItemsMatchingOpenTabs(
71 const std::set<std::string>& open_urls,
72 std::vector<InstantMostVisitedItem>* items) {
73 for (size_t i = 0; i < items->size(); ) {
74 const std::string& url = (*items)[i].url.spec();
75 if (ShouldRemoveURL(open_urls, url, items->size()))
76 items->erase(items->begin() + i);
77 else
78 ++i;
79 }
80 }
81
82 // static
RemovePageValuesMatchingOpenTabs(const std::set<std::string> & open_urls,base::ListValue * pages_value)83 void MostVisitedTilesExperiment::RemovePageValuesMatchingOpenTabs(
84 const std::set<std::string>& open_urls,
85 base::ListValue* pages_value) {
86 for (size_t i = 0; i < pages_value->GetSize(); ) {
87 base::DictionaryValue* page_value;
88 std::string url;
89 if (pages_value->GetDictionary(i, &page_value) &&
90 page_value->GetString("url", &url) &&
91 ShouldRemoveURL(open_urls, url, pages_value->GetSize())) {
92 pages_value->Remove(*page_value, &i);
93 } else {
94 ++i;
95 }
96 }
97 }
98
99 // static
LogInHistogram(NtpTileExperimentActions action)100 void MostVisitedTilesExperiment::LogInHistogram(
101 NtpTileExperimentActions action) {
102 UMA_HISTOGRAM_ENUMERATION(kMostVisitedExperimentHistogramName,
103 action,
104 NUM_NTP_TILE_EXPERIMENT_ACTIONS);
105 }
106
107 // static
ShouldRemoveURL(const std::set<std::string> & open_urls,const std::string & url,const size_t size)108 bool MostVisitedTilesExperiment::ShouldRemoveURL(
109 const std::set<std::string>& open_urls,
110 const std::string& url,
111 const size_t size) {
112 if (open_urls.count(url) == 0)
113 return false;
114
115 if (size <= kMinUrlSuggestions) {
116 LogInHistogram(NTP_TILE_EXPERIMENT_ACTION_DID_NOT_REMOVE_URL);
117 return false;
118 }
119
120 LogInHistogram(NTP_TILE_EXPERIMENT_ACTION_REMOVED_URL);
121 return true;
122 }
123
124 } // namespace history
125