Cache listener extension ids.

Previously launcherSearchProvider API has always enumerated all enabled extensions to list up listener extensions.
This CL changes to cache the list.

BUG=488329

Review URL: https://codereview.chromium.org/1137603005

Cr-Commit-Position: refs/heads/master@{#330478}

chrome/browser/chromeos/launcher_search_provider/service.cc

@@ -28,9 +28,11 @@ Service::Service(Profile* profile,
       provider_(nullptr),
       query_id_(0),
       is_query_running_(false) {
+  extension_registry_->AddObserver(this);
 }
 
 Service::~Service() {
+  extension_registry_->RemoveObserver(this);
 }
 
 // static
@@ -50,8 +52,8 @@ void Service::OnQueryStarted(app_list::LauncherSearchProvider* provider,
   extensions::EventRouter* event_router =
       extensions::EventRouter::Get(profile_);
 
-  std::set<ExtensionId> extension_ids = GetListenerExtensionIds();
-  for (const ExtensionId extension_id : extension_ids) {
+  CacheListenerExtensionIds();
+  for (const ExtensionId extension_id : *cached_listener_extension_ids_.get()) {
     // Convert query_id_ to string here since queryId is defined as string in
     // javascript side API while we use uint32 internally to generate it.
     event_router->DispatchEventToExtension(
@@ -70,8 +72,8 @@ void Service::OnQueryEnded() {
   extensions::EventRouter* event_router =
       extensions::EventRouter::Get(profile_);
 
-  std::set<ExtensionId> extension_ids = GetListenerExtensionIds();
-  for (const ExtensionId extension_id : extension_ids) {
+  CacheListenerExtensionIds();
+  for (const ExtensionId extension_id : *cached_listener_extension_ids_.get()) {
     event_router->DispatchEventToExtension(
         extension_id,
         make_scoped_ptr(new extensions::Event(
@@ -84,7 +86,8 @@ void Service::OnQueryEnded() {
 
 void Service::OnOpenResult(const ExtensionId& extension_id,
                            const std::string& item_id) {
-  CHECK(ContainsValue(GetListenerExtensionIds(), extension_id));
+  CacheListenerExtensionIds();
+  CHECK(ContainsValue(*cached_listener_extension_ids_.get(), extension_id));
 
   extensions::EventRouter* event_router =
       extensions::EventRouter::Get(profile_);
@@ -107,7 +110,8 @@ void Service::SetSearchResults(
     return;
 
   // If |extension| is not in the listener extensions list, ignore it.
-  if (!ContainsValue(GetListenerExtensionIds(), extension->id()))
+  CacheListenerExtensionIds();
+  if (!ContainsValue(*cached_listener_extension_ids_.get(), extension->id()))
     return;
 
   // Set search results to provider.
@@ -133,9 +137,26 @@ bool Service::IsQueryRunning() const {
   return is_query_running_;
 }
 
-std::set<ExtensionId> Service::GetListenerExtensionIds() {
-  // TODO(yawano): Cache this result for optimization (crbug.com/440649).
-  std::set<ExtensionId> extension_ids;
+void Service::OnExtensionLoaded(content::BrowserContext* browser_context,
+                                const extensions::Extension* extension) {
+  // Invalidate cache.
+  cached_listener_extension_ids_.reset();
+}
+
+void Service::OnExtensionUnloaded(
+    content::BrowserContext* browser_context,
+    const extensions::Extension* extension,
+    extensions::UnloadedExtensionInfo::Reason reason) {
+  // Invalidate cache.
+  cached_listener_extension_ids_.reset();
+}
+
+void Service::CacheListenerExtensionIds() {
+  // If it's already cached, do nothing.
+  if (cached_listener_extension_ids_)
+    return;
+
+  cached_listener_extension_ids_.reset(new std::set<ExtensionId>());
 
   const ExtensionSet& extension_set = extension_registry_->enabled_extensions();
   for (scoped_refptr<const extensions::Extension> extension : extension_set) {
@@ -144,10 +165,8 @@ std::set<ExtensionId> Service::GetListenerExtensionIds() {
     const bool has_permission = permission_data->HasAPIPermission(
         extensions::APIPermission::kLauncherSearchProvider);
     if (has_permission)
-      extension_ids.insert(extension->id());
+      cached_listener_extension_ids_->insert(extension->id());
   }
-
-  return extension_ids;
 }
 
 }  // namespace launcher_search_provider

chrome/browser/chromeos/launcher_search_provider/service.h

@@ -12,6 +12,7 @@
 #include "components/keyed_service/core/keyed_service.h"
 #include "content/public/browser/browser_context.h"
 #include "extensions/browser/event_router.h"
+#include "extensions/browser/extension_registry_observer.h"
 #include "extensions/common/extension.h"
 
 namespace app_list {
@@ -31,7 +32,8 @@ const int kMaxSearchResultScore = 4;
 // This service provides access control for it.
 //
 // TODO(yawano): Implement opt-in control (crbug.com/440649).
-class Service : public KeyedService {
+class Service : public KeyedService,
+                public extensions::ExtensionRegistryObserver {
  public:
   Service(Profile* profile, extensions::ExtensionRegistry* extension_registry);
   ~Service() override;
@@ -60,15 +62,25 @@ class Service : public KeyedService {
   // Returns true if there is a running query.
   bool IsQueryRunning() const;
 
+  // extensions::ExtensionRegistryObserver override.
+  void OnExtensionLoaded(content::BrowserContext* browser_context,
+                         const extensions::Extension* extension) override;
+  void OnExtensionUnloaded(
+      content::BrowserContext* browser_context,
+      const extensions::Extension* extension,
+      extensions::UnloadedExtensionInfo::Reason reason) override;
+
  private:
-  // Returns extension ids of listener extensions.
-  std::set<extensions::ExtensionId> GetListenerExtensionIds();
+  // Cache listener extension ids and set them to
+  // |cached_listener_extension_ids_|.
+  void CacheListenerExtensionIds();
 
   Profile* const profile_;
   extensions::ExtensionRegistry* extension_registry_;
   app_list::LauncherSearchProvider* provider_;
   int query_id_;
   bool is_query_running_;
+  scoped_ptr<std::set<extensions::ExtensionId>> cached_listener_extension_ids_;
 
   DISALLOW_COPY_AND_ASSIGN(Service);
 };