src/extensions/browser/state_store.cc

   1 // Copyright 2014 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 "extensions/browser/state_store.h"
   6
   7 #include "base/bind.h"
   8 #include "base/message_loop/message_loop.h"
   9 #include "content/public/browser/browser_context.h"
  10 #include "content/public/browser/notification_service.h"
  11 #include "content/public/browser/notification_types.h"
  12 #include "extensions/browser/extension_registry.h"
  13 #include "extensions/common/extension.h"
  14
  15 namespace {
  16
  17 // Delay, in seconds, before we should open the State Store database. We
  18 // defer it to avoid slowing down startup. See http://crbug.com/161848
  19 const int kInitDelaySeconds = 1;
  20
  21 std::string GetFullKey(const std::string& extension_id,
  22                        const std::string& key) {
  23   return extension_id + "." + key;
  24 }
  25
  26 }  // namespace
  27
  28 namespace extensions {
  29
  30 // Helper class to delay tasks until we're ready to start executing them.
  31 class StateStore::DelayedTaskQueue {
  32  public:
  33   DelayedTaskQueue() : ready_(false) {}
  34   ~DelayedTaskQueue() {}
  35
  36   // Queues up a task for invoking once we're ready. Invokes immediately if
  37   // we're already ready.
  38   void InvokeWhenReady(base::Closure task);
  39
  40   // Marks us ready, and invokes all pending tasks.
  41   void SetReady();
  42
  43   // Return whether or not the DelayedTaskQueue is |ready_|.
  44   bool ready() const { return ready_; }
  45
  46  private:
  47   bool ready_;
  48   std::vector<base::Closure> pending_tasks_;
  49 };
  50
  51 void StateStore::DelayedTaskQueue::InvokeWhenReady(base::Closure task) {
  52   if (ready_) {
  53     task.Run();
  54   } else {
  55     pending_tasks_.push_back(task);
  56   }
  57 }
  58
  59 void StateStore::DelayedTaskQueue::SetReady() {
  60   ready_ = true;
  61
  62   for (size_t i = 0; i < pending_tasks_.size(); ++i)
  63     pending_tasks_[i].Run();
  64   pending_tasks_.clear();
  65 }
  66
  67 StateStore::StateStore(content::BrowserContext* context,
  68                        const base::FilePath& db_path,
  69                        bool deferred_load)
  70     : db_path_(db_path),
  71       task_queue_(new DelayedTaskQueue()),
  72       extension_registry_observer_(this) {
  73   extension_registry_observer_.Add(ExtensionRegistry::Get(context));
  74
  75   if (deferred_load) {
  76     // Don't Init() until the first page is loaded or the embedder explicitly
  77     // requests it.
  78     registrar_.Add(
  79         this,
  80         content::NOTIFICATION_LOAD_COMPLETED_MAIN_FRAME,
  81         content::NotificationService::AllBrowserContextsAndSources());
  82   } else {
  83     Init();
  84   }
  85 }
  86
  87 StateStore::StateStore(content::BrowserContext* context,
  88                        scoped_ptr<ValueStore> value_store)
  89     : store_(value_store.Pass()),
  90       task_queue_(new DelayedTaskQueue()),
  91       extension_registry_observer_(this) {
  92   extension_registry_observer_.Add(ExtensionRegistry::Get(context));
  93
  94   // This constructor is for testing. No need to delay Init.
  95   Init();
  96 }
  97
  98 StateStore::~StateStore() {
  99 }
 100
 101 void StateStore::RequestInitAfterDelay() {
 102   InitAfterDelay();
 103 }
 104
 105 void StateStore::RegisterKey(const std::string& key) {
 106   registered_keys_.insert(key);
 107 }
 108
 109 void StateStore::GetExtensionValue(const std::string& extension_id,
 110                                    const std::string& key,
 111                                    ReadCallback callback) {
 112   task_queue_->InvokeWhenReady(base::Bind(&ValueStoreFrontend::Get,
 113                                           base::Unretained(&store_),
 114                                           GetFullKey(extension_id, key),
 115                                           callback));
 116 }
 117
 118 void StateStore::SetExtensionValue(const std::string& extension_id,
 119                                    const std::string& key,
 120                                    scoped_ptr<base::Value> value) {
 121   task_queue_->InvokeWhenReady(base::Bind(&ValueStoreFrontend::Set,
 122                                           base::Unretained(&store_),
 123                                           GetFullKey(extension_id, key),
 124                                           base::Passed(&value)));
 125 }
 126
 127 void StateStore::RemoveExtensionValue(const std::string& extension_id,
 128                                       const std::string& key) {
 129   task_queue_->InvokeWhenReady(base::Bind(&ValueStoreFrontend::Remove,
 130                                           base::Unretained(&store_),
 131                                           GetFullKey(extension_id, key)));
 132 }
 133
 134 bool StateStore::IsInitialized() const {
 135   return task_queue_->ready();
 136 }
 137
 138 void StateStore::Observe(int type,
 139                          const content::NotificationSource& source,
 140                          const content::NotificationDetails& details) {
 141   DCHECK_EQ(type, content::NOTIFICATION_LOAD_COMPLETED_MAIN_FRAME);
 142   registrar_.RemoveAll();
 143   InitAfterDelay();
 144 }
 145
 146 void StateStore::OnExtensionWillBeInstalled(
 147     content::BrowserContext* browser_context,
 148     const Extension* extension,
 149     bool is_update,
 150     bool from_ephemeral,
 151     const std::string& old_name) {
 152   RemoveKeysForExtension(extension->id());
 153 }
 154
 155 void StateStore::OnExtensionUninstalled(
 156     content::BrowserContext* browser_context,
 157     const Extension* extension,
 158     extensions::UninstallReason reason) {
 159   RemoveKeysForExtension(extension->id());
 160 }
 161
 162 void StateStore::Init() {
 163   // Could be called twice if InitAfterDelay() is requested explicitly by the
 164   // embedder in addition to internally after first page load.
 165   if (IsInitialized())
 166     return;
 167
 168   if (!db_path_.empty())
 169     store_.Init(db_path_);
 170   task_queue_->SetReady();
 171 }
 172
 173 void StateStore::InitAfterDelay() {
 174   if (IsInitialized())
 175     return;
 176
 177   base::MessageLoop::current()->PostDelayedTask(
 178       FROM_HERE,
 179       base::Bind(&StateStore::Init, AsWeakPtr()),
 180       base::TimeDelta::FromSeconds(kInitDelaySeconds));
 181 }
 182
 183 void StateStore::RemoveKeysForExtension(const std::string& extension_id) {
 184   for (std::set<std::string>::iterator key = registered_keys_.begin();
 185        key != registered_keys_.end();
 186        ++key) {
 187     task_queue_->InvokeWhenReady(base::Bind(&ValueStoreFrontend::Remove,
 188                                             base::Unretained(&store_),
 189                                             GetFullKey(extension_id, *key)));
 190   }
 191 }
 192
 193 }  // namespace extensions