1 // Copyright 2016 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/ntp_snippets/remote/request_throttler.h"
6
7 #include <climits>
8 #include <set>
9 #include <vector>
10
11 #include "base/logging.h"
12 #include "base/metrics/histogram.h"
13 #include "base/strings/string_number_conversions.h"
14 #include "base/strings/string_split.h"
15 #include "base/strings/stringprintf.h"
16 #include "base/time/time.h"
17 #include "components/ntp_snippets/features.h"
18 #include "components/ntp_snippets/ntp_snippets_constants.h"
19 #include "components/ntp_snippets/pref_names.h"
20 #include "components/prefs/pref_registry_simple.h"
21 #include "components/prefs/pref_service.h"
22 #include "components/variations/variations_associated_data.h"
23
24 namespace ntp_snippets {
25
26 namespace {
27
28 // Enumeration listing all possible outcomes for fetch attempts. Used for UMA
29 // histogram, so do not change existing values. Insert new values at the end,
30 // and update the histogram definition.
31 enum class RequestStatus {
32 INTERACTIVE_QUOTA_GRANTED,
33 BACKGROUND_QUOTA_GRANTED,
34 BACKGROUND_QUOTA_EXCEEDED,
35 INTERACTIVE_QUOTA_EXCEEDED,
36 REQUEST_STATUS_COUNT
37 };
38
39 // Quota value to use if no quota should be applied (by default).
40 const int kUnlimitedQuota = INT_MAX;
41
42 } // namespace
43
44 struct RequestThrottler::RequestTypeInfo {
45 const char* name;
46 const char* count_pref;
47 const char* interactive_count_pref;
48 const char* day_pref;
49 const int default_quota;
50 const int default_interactive_quota;
51 };
52
53 // When adding a new type here, extend also the "RequestThrottlerTypes"
54 // <histogram_suffixes> in histograms.xml with the |name| string.
55 const RequestThrottler::RequestTypeInfo RequestThrottler::kRequestTypeInfo[] = {
56 // The following three types share the same prefs. They differ in quota
57 // values (and UMA histograms).
58 // RequestCounter::RequestType::CONTENT_SUGGESTION_FETCHER_RARE_NTP_USER,
59 {"SuggestionFetcherRareNTPUser", prefs::kSnippetFetcherRequestCount,
60 prefs::kSnippetFetcherInteractiveRequestCount,
61 prefs::kSnippetFetcherRequestsDay, 5, kUnlimitedQuota},
62 // RequestCounter::RequestType::CONTENT_SUGGESTION_FETCHER_ACTIVE_NTP_USER,
63 {"SuggestionFetcherActiveNTPUser", prefs::kSnippetFetcherRequestCount,
64 prefs::kSnippetFetcherInteractiveRequestCount,
65 prefs::kSnippetFetcherRequestsDay, 20, kUnlimitedQuota},
66 // RequestCounter::RequestType::CONTENT_SUGGESTION_FETCHER_ACTIVE_SUGGESTIONS_CONSUMER,
67 {"SuggestionFetcherActiveSuggestionsConsumer",
68 prefs::kSnippetFetcherRequestCount,
69 prefs::kSnippetFetcherInteractiveRequestCount,
70 prefs::kSnippetFetcherRequestsDay, 20, kUnlimitedQuota},
71 // RequestCounter::RequestType::CONTENT_SUGGESTION_THUMBNAIL,
72 {"SuggestionThumbnailFetcher", prefs::kSnippetThumbnailsRequestCount,
73 prefs::kSnippetThumbnailsInteractiveRequestCount,
74 prefs::kSnippetThumbnailsRequestsDay, kUnlimitedQuota, kUnlimitedQuota}};
75
RequestThrottler(PrefService * pref_service,RequestType type)76 RequestThrottler::RequestThrottler(PrefService* pref_service, RequestType type)
77 : pref_service_(pref_service),
78 type_info_(kRequestTypeInfo[static_cast<int>(type)]) {
79 DCHECK(pref_service);
80
81 std::string quota = variations::GetVariationParamValueByFeature(
82 ntp_snippets::kArticleSuggestionsFeature,
83 base::StringPrintf("quota_%s", GetRequestTypeName()));
84 if (!base::StringToInt(quota, "a_)) {
85 LOG_IF(WARNING, !quota.empty())
86 << "Invalid variation parameter for quota for " << GetRequestTypeName();
87 quota_ = type_info_.default_quota;
88 }
89
90 std::string interactive_quota = variations::GetVariationParamValueByFeature(
91 ntp_snippets::kArticleSuggestionsFeature,
92 base::StringPrintf("interactive_quota_%s", GetRequestTypeName()));
93 if (!base::StringToInt(interactive_quota, &interactive_quota_)) {
94 LOG_IF(WARNING, !interactive_quota.empty())
95 << "Invalid variation parameter for interactive quota for "
96 << GetRequestTypeName();
97 interactive_quota_ = type_info_.default_interactive_quota;
98 }
99
100 // Since the histogram names are dynamic, we cannot use the standard macros
101 // and we need to lookup the histograms, instead.
102 int status_count = static_cast<int>(RequestStatus::REQUEST_STATUS_COUNT);
103 // Corresponds to UMA_HISTOGRAM_ENUMERATION(name, sample, |status_count|).
104 histogram_request_status_ = base::LinearHistogram::FactoryGet(
105 base::StringPrintf("NewTabPage.RequestThrottler.RequestStatus_%s",
106 GetRequestTypeName()),
107 1, status_count, status_count + 1,
108 base::HistogramBase::kUmaTargetedHistogramFlag);
109 // Corresponds to UMA_HISTOGRAM_COUNTS_100(name, sample).
110 histogram_per_day_background_ = base::Histogram::FactoryGet(
111 base::StringPrintf("NewTabPage.RequestThrottler.PerDay_%s",
112 GetRequestTypeName()),
113 1, 100, 50, base::HistogramBase::kUmaTargetedHistogramFlag);
114 // Corresponds to UMA_HISTOGRAM_COUNTS_100(name, sample).
115 histogram_per_day_interactive_ = base::Histogram::FactoryGet(
116 base::StringPrintf("NewTabPage.RequestThrottler.PerDayInteractive_%s",
117 GetRequestTypeName()),
118 1, 100, 50, base::HistogramBase::kUmaTargetedHistogramFlag);
119 }
120
121 // static
RegisterProfilePrefs(PrefRegistrySimple * registry)122 void RequestThrottler::RegisterProfilePrefs(PrefRegistrySimple* registry) {
123 // Collect all pref keys in a set to make sure we register each key exactly
124 // once, even if they repeat.
125 std::set<std::string> keys_to_register;
126 for (const RequestTypeInfo& info : kRequestTypeInfo) {
127 keys_to_register.insert(info.day_pref);
128 keys_to_register.insert(info.count_pref);
129 keys_to_register.insert(info.interactive_count_pref);
130 }
131
132 for (const std::string& key : keys_to_register) {
133 registry->RegisterIntegerPref(key, 0);
134 }
135 }
136
DemandQuotaForRequest(bool interactive_request)137 bool RequestThrottler::DemandQuotaForRequest(bool interactive_request) {
138 ResetCounterIfDayChanged();
139
140 int new_count = GetCount(interactive_request) + 1;
141 SetCount(interactive_request, new_count);
142 bool available = (new_count <= GetQuota(interactive_request));
143
144 if (interactive_request) {
145 histogram_request_status_->Add(static_cast<int>(
146 available ? RequestStatus::INTERACTIVE_QUOTA_GRANTED
147 : RequestStatus::INTERACTIVE_QUOTA_EXCEEDED));
148 } else {
149 histogram_request_status_->Add(
150 static_cast<int>(available ? RequestStatus::BACKGROUND_QUOTA_GRANTED
151 : RequestStatus::BACKGROUND_QUOTA_EXCEEDED));
152 }
153 return available;
154 }
155
ResetCounterIfDayChanged()156 void RequestThrottler::ResetCounterIfDayChanged() {
157 // Get the date, "concatenated" into an int in "YYYYMMDD" format.
158 base::Time::Exploded now_exploded{};
159 base::Time::Now().LocalExplode(&now_exploded);
160 int now_day = 10000 * now_exploded.year + 100 * now_exploded.month +
161 now_exploded.day_of_month;
162
163 if (!HasDay()) {
164 // The counter is used for the first time in this profile.
165 SetDay(now_day);
166 } else if (now_day != GetDay()) {
167 // Day has changed - report the number of requests from the previous day.
168 histogram_per_day_background_->Add(GetCount(/*interactive_request=*/false));
169 histogram_per_day_interactive_->Add(GetCount(/*interactive_request=*/true));
170 // Reset the counters.
171 SetCount(/*interactive_request=*/false, 0);
172 SetCount(/*interactive_request=*/true, 0);
173 SetDay(now_day);
174 }
175 }
176
GetRequestTypeName() const177 const char* RequestThrottler::GetRequestTypeName() const {
178 return type_info_.name;
179 }
180
181 // TODO(jkrcal): turn RequestTypeInfo into a proper class, move those methods
182 // onto the class and hide the members.
GetQuota(bool interactive_request) const183 int RequestThrottler::GetQuota(bool interactive_request) const {
184 return interactive_request ? interactive_quota_ : quota_;
185 }
186
GetCount(bool interactive_request) const187 int RequestThrottler::GetCount(bool interactive_request) const {
188 return pref_service_->GetInteger(interactive_request
189 ? type_info_.interactive_count_pref
190 : type_info_.count_pref);
191 }
192
SetCount(bool interactive_request,int count)193 void RequestThrottler::SetCount(bool interactive_request, int count) {
194 pref_service_->SetInteger(interactive_request
195 ? type_info_.interactive_count_pref
196 : type_info_.count_pref,
197 count);
198 }
199
GetDay() const200 int RequestThrottler::GetDay() const {
201 return pref_service_->GetInteger(type_info_.day_pref);
202 }
203
SetDay(int day)204 void RequestThrottler::SetDay(int day) {
205 pref_service_->SetInteger(type_info_.day_pref, day);
206 }
207
HasDay() const208 bool RequestThrottler::HasDay() const {
209 return pref_service_->HasPrefPath(type_info_.day_pref);
210 }
211
212 } // namespace ntp_snippets
213