[fsp] Add support for observing entries and notifying about changes.

chrome/browser/chromeos/file_system_provider/service.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_SERVICE_H_
 #define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_SERVICE_H_
 
 #include <map>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/files/file.h"
 #include "base/files/file_path.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/threading/thread_checker.h"
 #include "base/values.h"
 #include "chrome/browser/chromeos/file_system_provider/observer.h"
+#include "chrome/browser/chromeos/file_system_provider/provided_file_system_interface.h"
+#include "chrome/browser/chromeos/file_system_provider/provided_file_system_observer.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/extensions/api/file_system_provider.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "content/public/browser/browser_context.h"
 #include "extensions/browser/extension_registry_observer.h"
 #include "extensions/common/extension.h"
 
 namespace extensions {
 class ExtensionRegistry;
 }  // namespace extensions
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }  // namespace user_prefs
 
 namespace chromeos {
 namespace file_system_provider {
 
 // Key names for preferences.
 extern const char kPrefKeyFileSystemId[];
 extern const char kPrefKeyDisplayName[];
 extern const char kPrefKeyWritable[];
+extern const char kPrefKeySupportsNotifyTag[];
 
 class ProvidedFileSystemFactoryInterface;
 class ProvidedFileSystemInfo;
 class ProvidedFileSystemInterface;
 class ServiceFactory;
 
 // Registers preferences to remember registered file systems between reboots.
 void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
 
 // Manages and registers the file system provider service. Maintains provided
 // file systems.
 class Service : public KeyedService,
-                public extensions::ExtensionRegistryObserver {
+                public extensions::ExtensionRegistryObserver,
+                public ProvidedFileSystemObserver {
  public:
   typedef base::Callback<ProvidedFileSystemInterface*(
       Profile* profile,
       const ProvidedFileSystemInfo& file_system_info)>
       FileSystemFactoryCallback;
 
   // Reason for unmounting. In case of UNMOUNT_REASON_SHUTDOWN, the file system
   // will be remounted automatically after a reboot. In case of
   // UNMOUNT_REASON_USER it will be permanently unmounted.
   enum UnmountReason { UNMOUNT_REASON_USER, UNMOUNT_REASON_SHUTDOWN };
 
   Service(Profile* profile, extensions::ExtensionRegistry* extension_registry);
   virtual ~Service();
 
   // Sets a custom ProvidedFileSystemInterface factory. Used by unit tests,
   // where an event router is not available.
   void SetFileSystemFactoryForTesting(
       const FileSystemFactoryCallback& factory_callback);
 
   // Mounts a file system provided by an extension with the |extension_id|. If
   // |writable| is set to true, then the file system is mounted in a R/W mode.
-  // Otherwise, only read-only operations are supported. For success, returns
+  // Otherwise, only read-only operations are supported. If change notification
+  // tags are supported, then |supports_notify_tag| must be true. Note, that
+  // it is required in order to enable the internal cache. For success, returns
   // true, otherwise false.
   bool MountFileSystem(const std::string& extension_id,
                        const std::string& file_system_id,
                        const std::string& display_name,
-                       bool writable);
+                       bool writable,
+                       bool supports_notify_tag);
 
   // Unmounts a file system with the specified |file_system_id| for the
   // |extension_id|. For success returns true, otherwise false.
   bool UnmountFileSystem(const std::string& extension_id,
                          const std::string& file_system_id,
                          UnmountReason reason);
 
   // Requests unmounting of the file system. The callback is called when the
   // request is accepted or rejected, with an error code. Returns false if the
   // request could not been created, true otherwise.
@@ skipping 24 matching lines @@
 
   // extensions::ExtensionRegistryObserver overrides.
   virtual void OnExtensionUnloaded(
       content::BrowserContext* browser_context,
       const extensions::Extension* extension,
       extensions::UnloadedExtensionInfo::Reason reason) override;
   virtual void OnExtensionLoaded(
       content::BrowserContext* browser_context,
       const extensions::Extension* extension) override;
 
+  // ProvidedFileSystemInterface::Observer overrides.
+  virtual void OnObservedEntryChanged(
+      const ProvidedFileSystemInfo& file_system_info,
+      const base::FilePath& observed_path,
+      ProvidedFileSystemObserver::ChangeType change_type,
+      const ProvidedFileSystemObserver::ChildChanges& child_changes,
+      const base::Closure& callback) override;
+  virtual void OnObservedEntryTagUpdated(
+      const ProvidedFileSystemInfo& file_system_info,
+      const base::FilePath& observed_path) override;
+  virtual void OnObservedEntryListChanged(
+      const ProvidedFileSystemInfo& file_system_info) override;
+
  private:
   // Key is a pair of an extension id and file system id, which makes it
   // unique among the entire service instance.
   typedef std::pair<std::string, std::string> FileSystemKey;
 
   typedef std::map<FileSystemKey, ProvidedFileSystemInterface*>
       ProvidedFileSystemMap;
   typedef std::map<std::string, FileSystemKey> MountPointNameToKeyMap;
 
   // Called when the providing extension accepts or refuses a unmount request.
@@ skipping 23 matching lines @@
   base::ThreadChecker thread_checker_;
   base::WeakPtrFactory<Service> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Service);
 };
 
 }  // namespace file_system_provider
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_SERVICE_H_