Use |min| param to query a variable number of suggestions

components/suggestions/suggestions_service_impl.cc

 // Copyright 2014 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.
 
 #include "components/suggestions/suggestions_service_impl.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/feature_list.h"
 #include "base/location.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/sparse_histogram.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
 #include "components/data_use_measurement/core/data_use_user_data.h"
 #include "components/google/core/browser/google_util.h"
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "components/signin/core/browser/signin_manager_base.h"
 #include "components/suggestions/blacklist_store.h"
+#include "components/suggestions/features.h"
 #include "components/suggestions/image_manager.h"
 #include "components/suggestions/suggestions_store.h"
 #include "components/sync/driver/sync_service.h"
 #include "components/variations/net/variations_http_headers.h"
 #include "google_apis/gaia/gaia_constants.h"
 #include "google_apis/gaia/oauth2_token_service.h"
 #include "net/base/escape.h"
 #include "net/base/load_flags.h"
 #include "net/base/net_errors.h"
 #include "net/base/url_util.h"
@@ skipping 40 matching lines @@
 GURL GetGoogleBaseURL() {
   GURL url(google_util::CommandLineGoogleBaseURL());
   if (url.is_valid())
     return url;
   return GURL(kDefaultGoogleBaseURL);
 }
 
 // Format strings for the various suggestions URLs. They all have two string
 // params: The Google base URL and the device type.
 // TODO(mathp): Put this in TemplateURL.
-const char kSuggestionsURLFormat[] = "%schromesuggestions?t=%s";
+const char kSuggestionsURLFormat[] = "%schromesuggestions?%s";
 const char kSuggestionsBlacklistURLPrefixFormat[] =
     "%schromesuggestions/blacklist?t=%s&url=";
 const char kSuggestionsBlacklistClearURLFormat[] =
     "%schromesuggestions/blacklist/clear?t=%s";
 
 const char kSuggestionsBlacklistURLParam[] = "url";
+const char kSuggestionsDeviceParam[] = "t=%s";
+const char kSuggestionsUseAllParam[] = "min=0";

[Marc Treib, 2017/05/10 10:08:02]

The "0" should probably be configurable via a variation param?

[fhorschig, 2017/05/10 12:25:30]

Hmm, okay. I currently see no application, though.

[Marc Treib, 2017/05/10 12:32:24]

You never do, until you need it :D
Seriously though: If we can't control it server-side, there's little reason to
have the int in the first place.

[fhorschig, 2017/05/10 12:45:34]

It has direct a direct effect on the server-side. 
Still limited though, but it has. This is why I waited so long to
address the first comment here.

 
 #if defined(OS_ANDROID) || defined(OS_IOS)
 const char kDeviceType[] = "2";
 #else
 const char kDeviceType[] = "1";
 #endif
 
 // Format string for OAuth2 authentication headers.
 const char kAuthorizationHeaderFormat[] = "Authorization: Bearer %s";
 
@@ skipping 139 matching lines @@
 
 // static
 void SuggestionsServiceImpl::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   SuggestionsStore::RegisterProfilePrefs(registry);
   BlacklistStore::RegisterProfilePrefs(registry);
 }
 
 // static
 GURL SuggestionsServiceImpl::BuildSuggestionsURL() {
+  std::string query = base::StringPrintf(kSuggestionsDeviceParam, kDeviceType);
+  if (base::FeatureList::IsEnabled(kUseSuggestionsEvenIfFewFeature)) {
+    query = base::StringPrintf("%s&%s", query.c_str(), kSuggestionsUseAllParam);

[Marc Treib, 2017/05/10 10:08:02]

nit: I find this a bit confusing. Maybe don't reuse the "query" variable?

[fhorschig, 2017/05/10 12:25:30]

Done.

+  }
   return GURL(base::StringPrintf(
-      kSuggestionsURLFormat, GetGoogleBaseURL().spec().c_str(), kDeviceType));
+      kSuggestionsURLFormat, GetGoogleBaseURL().spec().c_str(), query.c_str()));
 }
 
 // static
 std::string SuggestionsServiceImpl::BuildSuggestionsBlacklistURLPrefix() {
   return base::StringPrintf(kSuggestionsBlacklistURLPrefixFormat,
                             GetGoogleBaseURL().spec().c_str(), kDeviceType);
 }
 
 // static
 GURL SuggestionsServiceImpl::BuildSuggestionsBlacklistURL(
@@ skipping 298 matching lines @@
     scheduling_delay_ = TimeDelta::FromSeconds(kDefaultSchedulingDelaySec);
   } else {
     TimeDelta candidate_delay =
         scheduling_delay_ * kSchedulingBackoffMultiplier;
     if (candidate_delay < TimeDelta::FromSeconds(kSchedulingMaxDelaySec))
       scheduling_delay_ = candidate_delay;
   }
 }
 
 }  // namespace suggestions