[fsp] Introduce file_system_provider::Service class for the FileSystemProvider API.

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 <vector>
+
+#include "base/observer_list.h"
+#include "chrome/browser/chromeos/file_system_provider/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"
+
+namespace chromeos {
+namespace file_system_provider {
+
+class ServiceFactory;
+
+// Manages and registers the fileSystemProvider service.
+class Service : public KeyedService {
+ public:
+  explicit Service(Profile* profile);
+  virtual ~Service();
+
+  // Registers a file system provided by an extension with the |extension_id|.
+  // For success, it returns a file system id, which is of the following format:
+  // |extension_id|-unique-hash, where unique is an auto-incremented non-zero
+  // number, and hash is the user profile hash.
+  // For failures, it returns an empty string.
+  std::string RegisterFileSystem(const std::string& extension_id,
+                                 const std::string& file_system_name);
+
+  // Unregisters a file system with the specified |file_system_id| for the
+  // |extension_id|. For success returns true, otherwise false.
+  bool UnregisterFileSystem(const std::string& extension_id,
+                            const std::string& file_system_id);
+
+  // Returns a list of currently registered file systems. All items are copied.
+  std::vector<ProvidedFileSystem> GetRegisteredFileSystems();
+
+  // Adds and removes observers.
+  void AddObserver(Observer* observer);
+  void RemoveObserver(Observer* observer);
+
+  // Gets the singleton instance for the |context|.
+  static Service* Get(content::BrowserContext* context);
+
+ private:
+  typedef std::map<std::string, ProvidedFileSystem> FileSystemMap;
+
+  Profile* profile_;
+  ObserverList<Observer> observers_;
+  FileSystemMap file_systems_;
+  int next_handle_;
+
+  DISALLOW_COPY_AND_ASSIGN(Service);
+};
+
+}  // namespace file_system_provider
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_SERVICE_H_