1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CHROME_BROWSER_METRICS_VARIATIONS_VARIATIONS_SERVICE_H_
#define CHROME_BROWSER_METRICS_VARIATIONS_VARIATIONS_SERVICE_H_
#include <string>
#include "base/compiler_specific.h"
#include "base/gtest_prod_util.h"
#include "base/memory/scoped_ptr.h"
#include "base/metrics/field_trial.h"
#include "base/time.h"
#include "base/timer.h"
#include "chrome/browser/metrics/proto/study.pb.h"
#include "chrome/browser/metrics/proto/trials_seed.pb.h"
#include "chrome/browser/metrics/variations/resource_request_allowed_notifier.h"
#include "chrome/common/chrome_version_info.h"
#include "googleurl/src/gurl.h"
#include "net/url_request/url_fetcher_delegate.h"
class PrefService;
namespace chrome_variations {
// Used to setup field trials based on stored variations seed data, and fetch
// new seed data from the variations server.
class VariationsService
: public net::URLFetcherDelegate,
public ResourceRequestAllowedNotifier::Observer {
public:
VariationsService();
// This constructor exists for injecting a mock notifier. It is meant for
// testing only. This instance will take ownership of |notifier|.
explicit VariationsService(ResourceRequestAllowedNotifier* notifier);
virtual ~VariationsService();
// Creates field trials based on Variations Seed loaded from local prefs. If
// there is a problem loading the seed data, all trials specified by the seed
// may not be created.
bool CreateTrialsFromSeed(PrefService* local_prefs);
// Calls FetchVariationsSeed once and repeats this periodically. See
// implementation for details on the period. Must be called after
// |CreateTrialsFromSeed|.
void StartRepeatedVariationsSeedFetch();
// Register Variations related prefs in Local State.
static void RegisterPrefs(PrefService* prefs);
// Exposed for testing.
void SetCreateTrialsFromSeedCalledForTesting(bool called);
protected:
// Starts the fetching process once, where |OnURLFetchComplete| is called with
// the response.
virtual void DoActualFetch();
private:
FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, CheckStudyChannel);
FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, CheckStudyLocale);
FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, CheckStudyPlatform);
FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, CheckStudyVersion);
FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, CheckStudyVersionWildcards);
FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, CheckStudyStartDate);
FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, DoNotFetchIfOffline);
FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, DoNotFetchIfOnlineToOnline);
FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, FetchOnReconnect);
FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, IsStudyExpired);
FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, LoadSeed);
FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, StoreSeed);
FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, ValidateStudy);
// Checks if prerequisites for fetching the Variations seed are met, and if
// so, performs the actual fetch using |DoActualFetch|.
void FetchVariationsSeed();
// net::URLFetcherDelegate implementation:
virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
// ResourceRequestAllowedNotifier::Observer implementation:
virtual void OnResourceRequestsAllowed() OVERRIDE;
// Store the given seed data to the given local prefs. Note that |seed_data|
// is assumed to be the raw serialized protobuf data stored in a string. It
// will be Base64Encoded for storage. If the string is invalid or the encoding
// fails, the |local_prefs| is left as is and the function returns false.
bool StoreSeedData(const std::string& seed_data,
const base::Time& seed_date,
PrefService* local_prefs);
// Returns whether |study| should be disabled according to its restriction
// parameters. Uses |version_info| for min / max version checks and
// |reference_date| for the start date check.
static bool ShouldAddStudy(const Study& study,
const chrome::VersionInfo& version_info,
const base::Time& reference_date);
// Checks whether a study is applicable for the given |channel| per |filter|.
static bool CheckStudyChannel(const Study_Filter& filter,
chrome::VersionInfo::Channel channel);
// Checks whether a study is applicable for the given |locale| per |filter|.
static bool CheckStudyLocale(const chrome_variations::Study_Filter& filter,
const std::string& locale);
// Checks whether a study is applicable for the given |platform| per |filter|.
static bool CheckStudyPlatform(const Study_Filter& filter,
chrome_variations::Study_Platform platform);
// Checks whether a study is applicable for the given version per |filter|.
static bool CheckStudyVersion(const Study_Filter& filter,
const std::string& version_string);
// Checks whether a study is applicable for the given date/time per |filter|.
static bool CheckStudyStartDate(const Study_Filter& filter,
const base::Time& date_time);
// Checks whether |study| is expired using the given date/time.
static bool IsStudyExpired(const Study& study,
const base::Time& date_time);
// Validates the sanity of |study| and computes the total probability.
static bool ValidateStudyAndComputeTotalProbability(
const Study& study,
base::FieldTrial::Probability* total_probability);
// Loads the Variations seed data from the given local prefs into |seed|. If
// there is a problem with loading, the pref value is cleared and false is
// returned. If successful, |seed| will contain the loaded data and true is
// returned.
bool LoadTrialsSeedFromPref(PrefService* local_prefs, TrialsSeed* seed);
// Creates and registers a field trial from the |study| data. Disables the
// trial if IsStudyExpired(study, reference_date) is true.
void CreateTrialFromStudy(const Study& study,
const base::Time& reference_date);
// Contains the current seed request. Will only have a value while a request
// is pending, and will be reset by |OnURLFetchComplete|.
scoped_ptr<net::URLFetcher> pending_seed_request_;
// The URL to use for querying the Variations server.
GURL variations_server_url_;
// Cached serial number from the most recently fetched Variations seed.
std::string variations_serial_number_;
// Tracks whether |CreateTrialsFromSeed| has been called, to ensure that
// it gets called prior to |StartRepeatedVariationsSeedFetch|.
bool create_trials_from_seed_called_;
// The timer used to repeatedly ping the server. Keep this as an instance
// member so if VariationsService goes out of scope, the timer is
// automatically canceled.
base::RepeatingTimer<VariationsService> timer_;
// Helper class used to tell this service if it's allowed to make network
// resource requests.
scoped_ptr<ResourceRequestAllowedNotifier> resource_request_allowed_notifier_;
// The start time of the last seed request. This is used to measure the
// latency of seed requests. Initially zero.
base::TimeTicks last_request_started_time_;
};
} // namespace chrome_variations
#endif // CHROME_BROWSER_METRICS_VARIATIONS_VARIATIONS_SERVICE_H_
|
