[SystemInfo API] Rewrite storage info provider using storage monitor impl

chrome/browser/extensions/api/system_info/system_info_api.cc

 // Copyright 2013 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 "chrome/browser/extensions/api/system_info/system_info_api.h"
 
 #include <set>
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/lazy_instance.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/singleton.h"
 #include "base/string_util.h"
+#include "base/sys_info.h"
+#include "base/task_runner_util.h"
 #include "base/values.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/api/system_info_cpu/cpu_info_provider.h"
 #include "chrome/browser/extensions/api/system_info_storage/storage_info_provider.h"
 #include "chrome/browser/extensions/event_names.h"
 #include "chrome/browser/extensions/event_router_forwarder.h"
+#include "chrome/browser/storage_monitor/removable_storage_observer.h"
+#include "chrome/browser/storage_monitor/storage_info.h"
+#include "chrome/browser/storage_monitor/storage_monitor.h"
 #include "chrome/common/extensions/api/experimental_system_info_cpu.h"
 #include "chrome/common/extensions/api/experimental_system_info_storage.h"
 #include "ui/gfx/display_observer.h"
 
 #if defined(USE_ASH)
 #include "ash/screen_ash.h"
 #include "ash/shell.h"
 #endif
 
 namespace extensions {
@@ skipping 18 matching lines @@
 bool IsAvailableCapacityChangedEvent(const std::string& event_name) {
   return event_name == event_names::kOnStorageAvailableCapacityChanged;
 }
 
 bool IsCpuUpdatedEvent(const std::string& event_name) {
   return event_name == event_names::kOnCpuUpdated;
 }
 
 // Event router for systemInfo API. It is a singleton instance shared by
 // multiple profiles.
-class SystemInfoEventRouter
-    : public gfx::DisplayObserver, public StorageInfoObserver {
+class SystemInfoEventRouter : public gfx::DisplayObserver,
+                              public chrome::RemovableStorageObserver,
+                              public StorageFreeSpaceObserver {
  public:
   static SystemInfoEventRouter* GetInstance();
 
   SystemInfoEventRouter();
   virtual ~SystemInfoEventRouter();
 
   // Add/remove event listener for the |event_name| event.
   void AddEventListener(const std::string& event_name);
   void RemoveEventListener(const std::string& event_name);
 
   // Return true if the |event_name| is an event from systemInfo namespace.
   static bool IsSystemInfoEvent(const std::string& event_name);
 
  private:
-  // StorageInfoObserver:
-  virtual void OnStorageFreeSpaceChanged(const std::string& id,
-                                         double new_value,
-                                         double old_value) OVERRIDE;
-  virtual void OnStorageAttached(
-      const std::string& id,
-      api::experimental_system_info_storage::StorageUnitType type,
-      double capacity,
-      double available_capacity) OVERRIDE;
-  virtual void OnStorageDetached(const std::string& id) OVERRIDE;
-
   // gfx::DisplayObserver:
   virtual void OnDisplayBoundsChanged(const gfx::Display& display) OVERRIDE;
   virtual void OnDisplayAdded(const gfx::Display& new_display) OVERRIDE;
   virtual void OnDisplayRemoved(const gfx::Display& old_display) OVERRIDE;
 
+  // chrome::RemovableStorageObserver implementation.
+  virtual void OnRemovableStorageAttached(
+      const chrome::StorageInfo& info) OVERRIDE;
+  virtual void OnRemovableStorageDetached(
+      const chrome::StorageInfo& info) OVERRIDE;
+
+  // StorageFreeSpaceObserver implementation.

[vandebo (ex-Chrome), 2013/05/28 20:00:29]

What was the conclusion of the discussion about having a freespace change event?

[Hongbo Min, 2013/05/29 01:05:38]

It is still pending now.

+  virtual void OnFreeSpaceChanged(const std::string& id,
+                                  double new_value,
+                                  double old_value) OVERRIDE;
+
+  void DispatchStorageAttachedEvent(const chrome::StorageInfo& info,
+                                    int64 avail_bytes);
+
   // Called from any thread to dispatch the systemInfo event to all extension
   // processes cross multiple profiles.
   void DispatchEvent(const std::string& event_name,
       scoped_ptr<base::ListValue> args);
 
   // The callbacks of querying storage info to start and stop watching the
   // storages. Called from UI thread.
-  void StartWatchingStorages(const StorageInfo& info, bool success);
-  void StopWatchingStorages(const StorageInfo& info, bool success);
+  void StartWatchingStorages(const StorageUnitList& info, bool success);
+  void StopWatchingStorages(const StorageUnitList& info, bool success);
 
   // The callback for CPU sampling cycle. Called from FILE thread.
   void OnNextCpuSampling(
       scoped_ptr<api::experimental_system_info_cpu::CpuUpdateInfo> info);
 
   // Called to dispatch the systemInfo.display.onDisplayChanged event.
   void OnDisplayChanged();
 
   // Used to record the event names being watched.
   std::multiset<std::string> watching_event_set_;
 
   DISALLOW_COPY_AND_ASSIGN(SystemInfoEventRouter);
 };
 
 static base::LazyInstance<SystemInfoEventRouter>::Leaky
   g_system_info_event_router = LAZY_INSTANCE_INITIALIZER;
 
 // static
 SystemInfoEventRouter* SystemInfoEventRouter::GetInstance() {
   return g_system_info_event_router.Pointer();
 }
 
 SystemInfoEventRouter::SystemInfoEventRouter() {
+  DCHECK(chrome::StorageMonitor::GetInstance());

[vandebo (ex-Chrome), 2013/05/28 20:00:29]

When is SystemInfoEventRouter created? We are changing the consumers of
StorageMonitor to only initialize it when they actively need it instead of
initializing it at startup.

[Hongbo Min, 2013/05/29 01:05:38]

The SystemInfoEventRouter instance is declared as a LazyInstance, which means it
will be created only when it is needed. See |g_system_info_event_router| and
|SytemInfoEventRouter::GetInstance()|

+  chrome::StorageMonitor::GetInstance()->AddObserver(this);
   StorageInfoProvider::Get()->AddObserver(this);
 }
 
 SystemInfoEventRouter::~SystemInfoEventRouter() {
   StorageInfoProvider::Get()->RemoveObserver(this);
+  if (chrome::StorageMonitor::GetInstance())
+    chrome::StorageMonitor::GetInstance()->RemoveObserver(this);
 }
 
 void SystemInfoEventRouter::StartWatchingStorages(
-    const StorageInfo& info, bool success) {
+    const StorageUnitList& info, bool success) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (!success)
     return;
 
-  for (StorageInfo::const_iterator it = info.begin(); it != info.end(); ++it) {
+  for (StorageUnitList::const_iterator it = info.begin();
+       it != info.end(); ++it) {
     StorageInfoProvider::Get()->StartWatching((*it)->id);
   }
 }
 
 void SystemInfoEventRouter::StopWatchingStorages(
-    const StorageInfo& info, bool success) {
+    const StorageUnitList& info, bool success) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (!success)
     return;
 
-  for (StorageInfo::const_iterator it = info.begin(); it != info.end(); ++it) {
+  for (StorageUnitList::const_iterator it = info.begin();
+       it != info.end(); ++it) {
     StorageInfoProvider::Get()->StopWatching((*it)->id);
   }
 }
 
 void SystemInfoEventRouter::AddEventListener(const std::string& event_name) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   watching_event_set_.insert(event_name);
   if (watching_event_set_.count(event_name) > 1)
     return;
@@ skipping 56 matching lines @@
 
 // static
 bool SystemInfoEventRouter::IsSystemInfoEvent(const std::string& event_name) {
   // TODO(hshi): simplify this once all systemInfo APIs are out of experimental.
   return (StartsWithASCII(event_name, kSystemInfoEventPrefix, true) ||
           StartsWithASCII(event_name, kExperimentalSystemInfoEventPrefix,
                           true));
 }
 
 // Called on UI thread since the observer is added from UI thread.
-void SystemInfoEventRouter::OnStorageFreeSpaceChanged(
-    const std::string& id, double new_value, double old_value) {
+void SystemInfoEventRouter::OnFreeSpaceChanged(
+    const std::string& id, double old_value, double new_value) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
   StorageChangeInfo info;
   info.id = id;
-  info.available_capacity = static_cast<double>(new_value);
+  info.old_value = old_value;
+  info.new_value = new_value;
 
   scoped_ptr<base::ListValue> args(new base::ListValue());
   args->Append(info.ToValue().release());
 
   DispatchEvent(event_names::kOnStorageAvailableCapacityChanged, args.Pass());
 }
 
-void SystemInfoEventRouter::OnStorageAttached(const std::string& id,
-                                              StorageUnitType type,
-                                              double capacity,
-                                              double available_capacity) {
-  StorageUnitInfo info;
-  info.id = id;
-  info.type = type;
-  info.capacity = capacity;
-  info.available_capacity = available_capacity;
+void SystemInfoEventRouter::OnRemovableStorageAttached(
+    const chrome::StorageInfo& info) {
+  base::FilePath mount_path(info.location());
+  base::PostTaskAndReplyWithResult(
+      BrowserThread::GetBlockingPool()->GetTaskRunnerWithShutdownBehavior(
+          base::SequencedWorkerPool::CONTINUE_ON_SHUTDOWN),
+      FROM_HERE,
+      base::Bind(&StorageInfoProvider::GetStorageFreeSpace,
+                 StorageInfoProvider::Get(), mount_path),
+      base::Bind(&SystemInfoEventRouter::DispatchStorageAttachedEvent,
+                 base::Unretained(this), info));
+}
+
+void SystemInfoEventRouter::DispatchStorageAttachedEvent(
+    const chrome::StorageInfo& info, int64 avail_bytes) {
+  StorageUnitInfo unit;
+  systeminfo::BuildStorageUnitInfo(info, &unit);
+
+  unit.available_capacity =
+      avail_bytes > 0 ? static_cast<double>(avail_bytes) : 0;
 
   scoped_ptr<base::ListValue> args(new base::ListValue);
-  args->Append(info.ToValue().release());
+  args->Append(unit.ToValue().release());
 
   DispatchEvent(event_names::kOnStorageAttached, args.Pass());
 }
 
-void SystemInfoEventRouter::OnStorageDetached(const std::string& id) {
+void SystemInfoEventRouter::OnRemovableStorageDetached(
+    const chrome::StorageInfo& info) {
   scoped_ptr<base::ListValue> args(new base::ListValue);
-  args->Append(new base::StringValue(id));
+  args->Append(new base::StringValue(info.device_id()));
 
   DispatchEvent(event_names::kOnStorageDetached, args.Pass());
 }
 
 void SystemInfoEventRouter::OnDisplayBoundsChanged(
     const gfx::Display& display) {
   OnDisplayChanged();
 }
 
 void SystemInfoEventRouter::OnDisplayAdded(const gfx::Display& new_display) {
@@ skipping 52 matching lines @@
 
 void SystemInfoAPI::OnListenerAdded(const EventListenerInfo& details) {
   SystemInfoEventRouter::GetInstance()->AddEventListener(details.event_name);
 }
 
 void SystemInfoAPI::OnListenerRemoved(const EventListenerInfo& details) {
   SystemInfoEventRouter::GetInstance()->RemoveEventListener(details.event_name);
 }
 
 }  // namespace extensions