Handle TemplateURLService load failure better

chrome/browser/search_engines/template_url_service.cc

Index: chrome/browser/search_engines/template_url_service.cc
diff --git a/chrome/browser/search_engines/template_url_service.cc b/chrome/browser/search_engines/template_url_service.cc
index 817756c296f27528bf9760a94e42b36057b6b35d..bbb4af4e01378c818346a2eb878b5597bcd4b4bd 100644
--- a/chrome/browser/search_engines/template_url_service.cc
+++ b/chrome/browser/search_engines/template_url_service.cc
@@ -418,79 +418,6 @@ bool TemplateURLService::LoadDefaultSearchProviderFromPrefs(
 }
 
 // static
-void TemplateURLService::SaveDefaultSearchProviderToPrefs(
-    const TemplateURL* t_url, PrefService* prefs) {
-  if (!prefs)
-    return;
-
-  bool enabled = false;
-  std::string search_url;
-  std::string suggest_url;
-  std::string instant_url;
-  std::string image_url;
-  std::string new_tab_url;
-  std::string search_url_post_params;
-  std::string suggest_url_post_params;
-  std::string instant_url_post_params;
-  std::string image_url_post_params;
-  std::string icon_url;
-  std::string encodings;
-  std::string short_name;
-  std::string keyword;
-  std::string id_string;
-  std::string prepopulate_id;
-  base::ListValue alternate_urls;
-  std::string search_terms_replacement_key;
-  if (t_url) {
-    DCHECK_EQ(TemplateURL::NORMAL, t_url->GetType());
-    enabled = true;
-    search_url = t_url->url();
-    suggest_url = t_url->suggestions_url();
-    instant_url = t_url->instant_url();
-    image_url = t_url->image_url();
-    new_tab_url = t_url->new_tab_url();
-    search_url_post_params = t_url->search_url_post_params();
-    suggest_url_post_params = t_url->suggestions_url_post_params();
-    instant_url_post_params = t_url->instant_url_post_params();
-    image_url_post_params = t_url->image_url_post_params();
-    GURL icon_gurl = t_url->favicon_url();
-    if (!icon_gurl.is_empty())
-      icon_url = icon_gurl.spec();
-    encodings = JoinString(t_url->input_encodings(), ';');
-    short_name = base::UTF16ToUTF8(t_url->short_name());
-    keyword = base::UTF16ToUTF8(t_url->keyword());
-    id_string = base::Int64ToString(t_url->id());
-    prepopulate_id = base::Int64ToString(t_url->prepopulate_id());
-    for (size_t i = 0; i < t_url->alternate_urls().size(); ++i)
-      alternate_urls.AppendString(t_url->alternate_urls()[i]);
-    search_terms_replacement_key = t_url->search_terms_replacement_key();
-  }
-  prefs->SetBoolean(prefs::kDefaultSearchProviderEnabled, enabled);
-  prefs->SetString(prefs::kDefaultSearchProviderSearchURL, search_url);
-  prefs->SetString(prefs::kDefaultSearchProviderSuggestURL, suggest_url);
-  prefs->SetString(prefs::kDefaultSearchProviderInstantURL, instant_url);
-  prefs->SetString(prefs::kDefaultSearchProviderImageURL, image_url);
-  prefs->SetString(prefs::kDefaultSearchProviderNewTabURL, new_tab_url);
-  prefs->SetString(prefs::kDefaultSearchProviderSearchURLPostParams,
-                   search_url_post_params);
-  prefs->SetString(prefs::kDefaultSearchProviderSuggestURLPostParams,
-                   suggest_url_post_params);
-  prefs->SetString(prefs::kDefaultSearchProviderInstantURLPostParams,
-                   instant_url_post_params);
-  prefs->SetString(prefs::kDefaultSearchProviderImageURLPostParams,
-                   image_url_post_params);
-  prefs->SetString(prefs::kDefaultSearchProviderIconURL, icon_url);
-  prefs->SetString(prefs::kDefaultSearchProviderEncodings, encodings);
-  prefs->SetString(prefs::kDefaultSearchProviderName, short_name);
-  prefs->SetString(prefs::kDefaultSearchProviderKeyword, keyword);
-  prefs->SetString(prefs::kDefaultSearchProviderID, id_string);
-  prefs->SetString(prefs::kDefaultSearchProviderPrepopulateID, prepopulate_id);
-  prefs->Set(prefs::kDefaultSearchProviderAlternateURLs, alternate_urls);
-  prefs->SetString(prefs::kDefaultSearchProviderSearchTermsReplacementKey,
-      search_terms_replacement_key);
-}
-
-// static
 base::string16 TemplateURLService::GenerateKeyword(const GURL& url) {
   DCHECK(url.is_valid());
   // Strip "www." off the front of the keyword; otherwise the keyword won't work
@@ -568,6 +495,79 @@ GURL TemplateURLService::GenerateSearchURLUsingTermsData(
       search_terms_data, NULL));
 }
 
+void TemplateURLService::SaveDefaultSearchProviderToPrefs(
+    const TemplateURL* t_url,
+    PrefService* prefs) const {
+  if (!prefs || load_failed_)
+    return;
+
+  bool enabled = false;
+  std::string search_url;
+  std::string suggest_url;
+  std::string instant_url;
+  std::string image_url;
+  std::string new_tab_url;
+  std::string search_url_post_params;
+  std::string suggest_url_post_params;
+  std::string instant_url_post_params;
+  std::string image_url_post_params;
+  std::string icon_url;
+  std::string encodings;
+  std::string short_name;
+  std::string keyword;
+  std::string id_string;
+  std::string prepopulate_id;
+  base::ListValue alternate_urls;
+  std::string search_terms_replacement_key;
+  if (t_url) {
+    DCHECK_EQ(TemplateURL::NORMAL, t_url->GetType());
+    enabled = true;
+    search_url = t_url->url();
+    suggest_url = t_url->suggestions_url();
+    instant_url = t_url->instant_url();
+    image_url = t_url->image_url();
+    new_tab_url = t_url->new_tab_url();
+    search_url_post_params = t_url->search_url_post_params();
+    suggest_url_post_params = t_url->suggestions_url_post_params();
+    instant_url_post_params = t_url->instant_url_post_params();
+    image_url_post_params = t_url->image_url_post_params();
+    GURL icon_gurl = t_url->favicon_url();
+    if (!icon_gurl.is_empty())
+      icon_url = icon_gurl.spec();
+    encodings = JoinString(t_url->input_encodings(), ';');
+    short_name = base::UTF16ToUTF8(t_url->short_name());
+    keyword = base::UTF16ToUTF8(t_url->keyword());
+    id_string = base::Int64ToString(t_url->id());
+    prepopulate_id = base::Int64ToString(t_url->prepopulate_id());
+    for (size_t i = 0; i < t_url->alternate_urls().size(); ++i)
+      alternate_urls.AppendString(t_url->alternate_urls()[i]);
+    search_terms_replacement_key = t_url->search_terms_replacement_key();
+  }
+  prefs->SetBoolean(prefs::kDefaultSearchProviderEnabled, enabled);
+  prefs->SetString(prefs::kDefaultSearchProviderSearchURL, search_url);
+  prefs->SetString(prefs::kDefaultSearchProviderSuggestURL, suggest_url);
+  prefs->SetString(prefs::kDefaultSearchProviderInstantURL, instant_url);
+  prefs->SetString(prefs::kDefaultSearchProviderImageURL, image_url);
+  prefs->SetString(prefs::kDefaultSearchProviderNewTabURL, new_tab_url);
+  prefs->SetString(prefs::kDefaultSearchProviderSearchURLPostParams,
+                   search_url_post_params);
+  prefs->SetString(prefs::kDefaultSearchProviderSuggestURLPostParams,
+                   suggest_url_post_params);
+  prefs->SetString(prefs::kDefaultSearchProviderInstantURLPostParams,
+                   instant_url_post_params);
+  prefs->SetString(prefs::kDefaultSearchProviderImageURLPostParams,
+                   image_url_post_params);
+  prefs->SetString(prefs::kDefaultSearchProviderIconURL, icon_url);
+  prefs->SetString(prefs::kDefaultSearchProviderEncodings, encodings);
+  prefs->SetString(prefs::kDefaultSearchProviderName, short_name);
+  prefs->SetString(prefs::kDefaultSearchProviderKeyword, keyword);
+  prefs->SetString(prefs::kDefaultSearchProviderID, id_string);
+  prefs->SetString(prefs::kDefaultSearchProviderPrepopulateID, prepopulate_id);
+  prefs->Set(prefs::kDefaultSearchProviderAlternateURLs, alternate_urls);
+  prefs->SetString(prefs::kDefaultSearchProviderSearchTermsReplacementKey,
+      search_terms_replacement_key);
+}
+
 bool TemplateURLService::CanReplaceKeyword(
     const base::string16& keyword,
     const GURL& url,
@@ -630,8 +630,7 @@ TemplateURL* TemplateURLService::GetTemplateURLForKeyword(
       keyword_to_template_map_.find(keyword));
   if (elem != keyword_to_template_map_.end())
     return elem->second;
-  return ((!loaded_ || load_failed_) &&
-      initial_default_search_provider_.get() &&
+  return (!loaded_ && initial_default_search_provider_.get() &&
       (initial_default_search_provider_->keyword() == keyword)) ?
       initial_default_search_provider_.get() : NULL;
 }
@@ -641,8 +640,7 @@ TemplateURL* TemplateURLService::GetTemplateURLForGUID(
   GUIDToTemplateMap::const_iterator elem(guid_to_template_map_.find(sync_guid));
   if (elem != guid_to_template_map_.end())
     return elem->second;
-  return ((!loaded_ || load_failed_) &&
-      initial_default_search_provider_.get() &&
+  return (!loaded_ && initial_default_search_provider_.get() &&
       (initial_default_search_provider_->sync_guid() == sync_guid)) ?
       initial_default_search_provider_.get() : NULL;
 }
@@ -654,8 +652,7 @@ TemplateURL* TemplateURLService::GetTemplateURLForHost(
     if (t_url)
       return t_url;
   }
-  return ((!loaded_ || load_failed_) &&
-      initial_default_search_provider_.get() &&
+  return (!loaded_ && initial_default_search_provider_.get() &&
       (GenerateSearchURL(initial_default_search_provider_.get()).host() ==
           host)) ? initial_default_search_provider_.get() : NULL;
 }
@@ -810,8 +807,8 @@ void TemplateURLService::IncrementUsageCount(TemplateURL* url) {
     return;
   ++url->data_.usage_count;
 
-  if (service_.get())
-    service_.get()->UpdateKeyword(url->data());
+  if (service_)
+    service_->UpdateKeyword(url->data());
 }
 
 void TemplateURLService::ResetTemplateURL(TemplateURL* url,
@@ -858,10 +855,8 @@ void TemplateURLService::SetUserSelectedDefaultSearchProvider(
 }
 
 TemplateURL* TemplateURLService::GetDefaultSearchProvider() {
-  if (loaded_ && !load_failed_)
-    return default_search_provider_;
-  // We're not loaded, rely on the default search provider stored in prefs.
-  return initial_default_search_provider_.get();
+  return loaded_ ?
+      default_search_provider_ : initial_default_search_provider_.get();
 }
 
 bool TemplateURLService::IsSearchResultsPageFromDefaultSearchProvider(
@@ -972,16 +967,13 @@ void TemplateURLService::Load() {
   if (loaded_ || load_handle_)
     return;
 
-  if (!service_.get()) {
+  if (!service_)
     service_ = WebDataService::FromBrowserContext(profile_);
-  }
 
-  if (service_.get()) {
+  if (service_)
     load_handle_ = service_->GetKeywords(this);
-  } else {
-    ChangeToLoadedState();
-    on_loaded_callbacks_.Notify();
-  }
+  else
+    OnFailedLoad();
 }
 
 scoped_ptr<TemplateURLService::Subscription>
@@ -1002,9 +994,7 @@ void TemplateURLService::OnWebDataServiceRequestDone(
   if (!result) {
     // Results are null if the database went away or (most likely) wasn't
     // loaded.
-    load_failed_ = true;
-    ChangeToLoadedState();
-    on_loaded_callbacks_.Notify();
+    OnFailedLoad();
     return;
   }
 
@@ -1280,6 +1270,15 @@ syncer::SyncMergeResult TemplateURLService::MergeDataAndStartSyncing(
   DCHECK(sync_processor.get());
   DCHECK(sync_error_factory.get());
   syncer::SyncMergeResult merge_result(type);
+
+  // Disable sync if we failed to load.
+  if (load_failed_) {

[Nicolas Zea, 2014/05/05 21:23:59]

Under what conditions is the load expected to fail, and is that meant to be a
permanent error? This will prevent search engine sync from working until the
next restart of Chrome.

Another option might be delaying the startup of the search engines datatype
until some condition is met. See for example
search_engine_data_type_controller.cc's StartModels method, which waits for the
TemplateURLService to load.

[Peter Kasting, 2014/05/05 21:33:32]

(1) Various tests
(2) Disk corruption preventing us from correctly loading the search engines from
disk

In both these cases, the TemplateURLService won't "recover" from this state, so
halting search engine sync until the next restart is the desired behavior.  My
concern was whether this would halt search engine sync indefinitely (across
restarts) until the user re-enabled the datatype.  If that's not true, I'm
happy.
We could instead add more code to that class to check whether the load failed
and just never start model association.  This would require me to expose an
accessor for TemplateURLService::load_failed_, which isn't a big deal.  It seems
like both methods would work; tell me which you prefer and I'll comply.

+    merge_result.set_error(syncer::SyncError(
+        FROM_HERE, syncer::SyncError::DATATYPE_ERROR,
+        "Local database load failed.", syncer::SEARCH_ENGINES));
+    return merge_result;
+  }
+
   sync_processor_ = sync_processor.Pass();
   sync_error_factory_ = sync_error_factory.Pass();
 
@@ -1785,6 +1784,24 @@ void TemplateURLService::ChangeToLoadedState() {
   loaded_ = true;
 }
 
+void TemplateURLService::OnFailedLoad() {
+  load_failed_ = true;
+  service_ = NULL;
+  // Have to call this before GetDefaultSearchProvider(), or that function will
+  // just return |initial_default_search_provider_|.
+  ChangeToLoadedState();
+  if (GetDefaultSearchProvider()) {
+    initial_default_search_provider_.reset();
+  } else if (initial_default_search_provider_) {
+    TemplateURL* default_search_provider =
+        initial_default_search_provider_.release();
+    AddNoNotify(default_search_provider,
+                default_search_provider->id() == kInvalidTemplateURLID);
+    SetDefaultSearchProviderNoNotify(default_search_provider);
+  }
+  on_loaded_callbacks_.Notify();
+}
+
 void TemplateURLService::ClearDefaultProviderFromPrefs() {
   // We overwrite user preferences. If the default search engine is managed,
   // there is no effect.
@@ -1885,7 +1902,7 @@ bool TemplateURLService::UpdateNoNotify(
   if (!existing_turl->sync_guid().empty())
     guid_to_template_map_[existing_turl->sync_guid()] = existing_turl;
 
-  if (service_.get())
+  if (service_)
     service_->UpdateKeyword(existing_turl->data());
 
   // Inform sync of the update.
@@ -2174,7 +2191,7 @@ bool TemplateURLService::SetDefaultSearchProviderNoNotify(TemplateURL* url) {
     // Don't mark the url as edited, otherwise we won't be able to rev the
     // template urls we ship with.
     url->data_.show_in_default_list = true;
-    if (service_.get() && (url->GetType() == TemplateURL::NORMAL))
+    if (service_ && (url->GetType() == TemplateURL::NORMAL))
       service_->UpdateKeyword(url->data());
 
     if (url->url_ref().HasGoogleBaseURLs()) {
@@ -2209,7 +2226,7 @@ bool TemplateURLService::SetDefaultSearchProviderNoNotify(TemplateURL* url) {
     }
   }
 
-  if (service_.get())
+  if (service_)
     service_->SetDefaultSearchProviderID(url ? url->id() : 0);
 
   // Inform sync the change to the show_in_default_list flag.
@@ -2261,7 +2278,7 @@ bool TemplateURLService::AddNoNotify(TemplateURL* template_url,
   if (newly_adding &&
       (template_url->GetType() !=
           TemplateURL::NORMAL_CONTROLLED_BY_EXTENSION)) {
-    if (service_.get())
+    if (service_)
       service_->AddKeyword(template_url->data());
 
     // Inform sync of the addition. Note that this will assign a GUID to
@@ -2288,7 +2305,7 @@ void TemplateURLService::RemoveNoNotify(TemplateURL* template_url) {
   template_urls_.erase(i);
 
   if (template_url->GetType() != TemplateURL::NORMAL_CONTROLLED_BY_EXTENSION) {
-    if (service_.get())
+    if (service_)
       service_->RemoveKeyword(template_url->id());
 
     // Inform sync of the deletion.
@@ -2358,7 +2375,7 @@ void TemplateURLService::RemoveProvidersCreatedByPolicy(
         *default_search_provider = NULL;
 
       i = template_urls->erase(i);
-      if (service_.get())
+      if (service_)
         service_->RemoveKeyword(template_url->id());
       delete template_url;
     } else {
@@ -2582,7 +2599,7 @@ void TemplateURLService::PatchMissingSyncGUIDs(
         (template_url->GetType() !=
             TemplateURL::NORMAL_CONTROLLED_BY_EXTENSION)) {
       template_url->data_.sync_guid = base::GenerateGUID();
-      if (service_.get())
+      if (service_)
         service_->UpdateKeyword(template_url->data());
     }
   }