Connecting UserClassifier to NtpSnippetsFetcher

components/ntp_snippets/remote/request_throttler.cc

Index: components/ntp_snippets/remote/request_throttler.cc
diff --git a/components/ntp_snippets/remote/request_throttler.cc b/components/ntp_snippets/remote/request_throttler.cc
index 4777f38156a0108c3866c439c373feed27d99df0..f9a2b5e73880c3600307e6754ca1f7a707c03dc2 100644
--- a/components/ntp_snippets/remote/request_throttler.cc
+++ b/components/ntp_snippets/remote/request_throttler.cc
@@ -5,6 +5,7 @@
 #include "components/ntp_snippets/remote/request_throttler.h"
 
 #include <climits>
+#include <set>
 #include <vector>
 
 #include "base/metrics/histogram.h"
@@ -50,19 +51,39 @@ struct RequestThrottler::RequestTypeInfo {
 // When adding a new type here, extend also the "RequestThrottlerTypes"
 // <histogram_suffixes> in histograms.xml with the |name| string.
 const RequestThrottler::RequestTypeInfo RequestThrottler::kRequestTypeInfo[] = {
-    // RequestCounter::RequestType::CONTENT_SUGGESTION_FETCHER,
-    {"SuggestionFetcher", prefs::kSnippetFetcherRequestCount,
+    // The following three types share the same prefs. They differ in quota
+    // values (and UMA histograms).
+    // RequestCounter::RequestType::CONTENT_SUGGESTION_FETCHER_RARE_NTP_USER,
+    {"SuggestionFetcherRareNTPUser", prefs::kSnippetFetcherRequestCount,
      prefs::kSnippetFetcherInteractiveRequestCount,
-     prefs::kSnippetFetcherRequestsDay, 50, kUnlimitedQuota},
-     // RequestCounter::RequestType::CONTENT_SUGGESTION_THUMBNAIL,
+     prefs::kSnippetFetcherRequestsDay, 5, kUnlimitedQuota},
+    // RequestCounter::RequestType::CONTENT_SUGGESTION_FETCHER_ACTIVE_NTP_USER,
+    {"SuggestionFetcherActiveNTPUser", prefs::kSnippetFetcherRequestCount,
+     prefs::kSnippetFetcherInteractiveRequestCount,
+     prefs::kSnippetFetcherRequestsDay, 20, kUnlimitedQuota},
+    // RequestCounter::RequestType::CONTENT_SUGGESTION_FETCHER_ACTIVE_SUGGESTIONS_CONSUMER,
+    {"SuggestionFetcherActiveSuggestionsConsumer",
+     prefs::kSnippetFetcherRequestCount,
+     prefs::kSnippetFetcherInteractiveRequestCount,
+     prefs::kSnippetFetcherRequestsDay, 20, kUnlimitedQuota},
+    // RequestCounter::RequestType::CONTENT_SUGGESTION_THUMBNAIL,
     {"SuggestionThumbnailFetcher", prefs::kSnippetThumbnailsRequestCount,
      prefs::kSnippetThumbnailsInteractiveRequestCount,
      prefs::kSnippetThumbnailsRequestsDay, kUnlimitedQuota, kUnlimitedQuota}};
 
 RequestThrottler::RequestThrottler(PrefService* pref_service, RequestType type)
     : pref_service_(pref_service),
-      type_info_(kRequestTypeInfo[static_cast<int>(type)]) {
+      type_info_(nullptr) {
   DCHECK(pref_service);
+  ChangeRequestType(type);
+}
+
+void RequestThrottler::ChangeRequestType(RequestType new_type) {
+  // Do the changes only if the new type differs from the previous one.
+  if (type_info_ == &kRequestTypeInfo[static_cast<int>(new_type)])
+    return;
+
+  type_info_ = &kRequestTypeInfo[static_cast<int>(new_type)];
 
   std::string quota = variations::GetVariationParamValue(
       ntp_snippets::kStudyName,
@@ -71,7 +92,7 @@ RequestThrottler::RequestThrottler(PrefService* pref_service, RequestType type)
     LOG_IF(WARNING, !quota.empty())
         << "Invalid variation parameter for quota for "
         << GetRequestTypeName();
-    quota_ = type_info_.default_quota;
+    quota_ = type_info_->default_quota;
   }
 
   std::string interactive_quota = variations::GetVariationParamValue(
@@ -81,7 +102,7 @@ RequestThrottler::RequestThrottler(PrefService* pref_service, RequestType type)
     LOG_IF(WARNING, !interactive_quota.empty())
         << "Invalid variation parameter for interactive quota for "
         << GetRequestTypeName();
-    interactive_quota_ = type_info_.default_interactive_quota;
+    interactive_quota_ = type_info_->default_interactive_quota;
   }
 
   // Since the histogram names are dynamic, we cannot use the standard macros
@@ -107,10 +128,18 @@ RequestThrottler::RequestThrottler(PrefService* pref_service, RequestType type)
 
 // static
 void RequestThrottler::RegisterProfilePrefs(PrefRegistrySimple* registry) {
+  std::set<std::string> registered;
   for (const RequestTypeInfo& info : kRequestTypeInfo) {
+    // Make sure we do not register the same prefs twice. Assuming that if any
+    // types share some prefs, they share all the prefs. Thus, checking, e.g.,
+    // day_pref is enough.
+    if (registered.count(info.day_pref) > 0)
+      continue;
+
+    registered.insert(info.day_pref);
+    registry->RegisterIntegerPref(info.day_pref, 0);
     registry->RegisterIntegerPref(info.count_pref, 0);
     registry->RegisterIntegerPref(info.interactive_count_pref, 0);
-    registry->RegisterIntegerPref(info.day_pref, 0);
   }
 }
 
@@ -152,7 +181,7 @@ void RequestThrottler::ResetCounterIfDayChanged() {
 }
 
 const char* RequestThrottler::GetRequestTypeName() const {
-  return type_info_.name;
+  return type_info_->name;
 }
 
 // TODO(jkrcal): turn RequestTypeInfo into a proper class, move those methods
@@ -163,27 +192,27 @@ int RequestThrottler::GetQuota(bool interactive_request) const {
 
 int RequestThrottler::GetCount(bool interactive_request) const {
   return pref_service_->GetInteger(interactive_request
-                                       ? type_info_.interactive_count_pref
-                                       : type_info_.count_pref);
+                                       ? type_info_->interactive_count_pref
+                                       : type_info_->count_pref);
 }
 
 void RequestThrottler::SetCount(bool interactive_request, int count) {
   pref_service_->SetInteger(interactive_request
-                                ? type_info_.interactive_count_pref
-                                : type_info_.count_pref,
+                                ? type_info_->interactive_count_pref
+                                : type_info_->count_pref,
                             count);
 }
 
 int RequestThrottler::GetDay() const {
-  return pref_service_->GetInteger(type_info_.day_pref);
+  return pref_service_->GetInteger(type_info_->day_pref);
 }
 
 void RequestThrottler::SetDay(int day) {
-  pref_service_->SetInteger(type_info_.day_pref, day);
+  pref_service_->SetInteger(type_info_->day_pref, day);
 }
 
 bool RequestThrottler::HasDay() const {
-  return pref_service_->HasPrefPath(type_info_.day_pref);
+  return pref_service_->HasPrefPath(type_info_->day_pref);
 }
 
 }  // namespace ntp_snippets