[ew] Add basic classes.

chrome/browser/extensions/api/file_system/entry_watcher_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_EXTENSIONS_API_FILE_SYSTEM_ENTRY_WATCHER_SERVICE_H_
+#define CHROME_BROWSER_EXTENSIONS_API_FILE_SYSTEM_ENTRY_WATCHER_SERVICE_H_
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include "base/memory/singleton.h"
+#include "base/memory/weak_ptr.h"
+#include "base/scoped_observer.h"
+#include "components/keyed_service/content/browser_context_keyed_service_factory.h"
+#include "components/keyed_service/core/keyed_service.h"
+#include "webkit/browser/fileapi/file_system_url.h"
+#include "webkit/browser/fileapi/watcher_manager.h"
+
+namespace content {
+class BrowserContext;
+}  // namespace content
+
+namespace storage {
+class FileSystemContext;
+}  // namespace storage
+
+namespace extensions {
+struct Event;
+class EventRouter;
+
+// Watches entries (files and directories) for changes. Created per profile.
+// TODO(mtomasz): Add support for watching files.
+class EntryWatcherService : public KeyedService,
+                            public storage::WatcherManager::Observer {
+ public:
+  typedef base::Callback<
+      void(const std::string& extension_id, scoped_ptr<Event> event)>
+      DispatchEventImplCallback;
+
+  typedef base::Callback<storage::FileSystemContext*(
+      const std::string& extension_id,
+      content::BrowserContext* context)> GetFileSystemContextImplCallback;
+
+  explicit EntryWatcherService(content::BrowserContext* context);
+  virtual ~EntryWatcherService();
+
+  // Watches a directory. Only one watcher can be set per the same |url| and
+  // |extension_id|.
+  void WatchDirectory(const std::string& extension_id,
+                      const storage::FileSystemURL& url,
+                      bool recursive,
+                      const storage::WatcherManager::StatusCallback& callback);
+
+  // Unwatches an entry (file or directory).
+  void UnwatchEntry(const std::string& extension_id,
+                    const storage::FileSystemURL& url,
+                    const storage::WatcherManager::StatusCallback& callback);
+
+  std::vector<storage::FileSystemURL> GetWatchedEntries(
+      const std::string& extension_id);
+
+  // storage::WatcherManager::Observer overrides.
+  virtual void OnEntryChanged(const storage::FileSystemURL& url) OVERRIDE;
+  virtual void OnEntryRemoved(const storage::FileSystemURL& url) OVERRIDE;
+
+  // Sets a custom dispatcher for tests in order to be able to verify dispatched
+  // events.
+  void SetDispatchEventImplForTesting(
+      const DispatchEventImplCallback& callback);
+
+  // Sets a custom context getter for tests in order to inject a testing
+  // file system context implementation.
+  void SetGetFileSystemContextImplForTesting(
+      const GetFileSystemContextImplCallback& callback);
+
+ private:
+  // Holds information about an active entry watcher.
+  struct EntryWatcher {
+    EntryWatcher();
+    EntryWatcher(const storage::FileSystemURL& url,
+                 bool directory,
+                 bool recursive);
+    ~EntryWatcher();
+
+    storage::FileSystemURL url;
+    bool directory;
+    bool recursive;
+  };
+
+  // Map from a file system url to a map from an extension id to an entry
+  // watcher descriptor.
+  typedef std::map<storage::FileSystemURL,
+                   std::map<std::string, EntryWatcher>,
+                   storage::FileSystemURL::Comparator> WatcherMap;
+
+  // Called when adding a directory watcher is completed with either a success
+  // or an error.
+  void OnWatchDirectoryCompleted(
+      storage::WatcherManager* watcher_manager,
+      const std::string& extension_id,
+      const storage::FileSystemURL& url,
+      bool recursive,
+      const storage::WatcherManager::StatusCallback& callback,
+      base::File::Error result);
+
+  // Called when removing a watcher is completed with either a success or an
+  // error.
+  void OnUnwatchEntryCompleted(
+      const std::string& extension_id,
+      const storage::FileSystemURL& url,
+      const storage::WatcherManager::StatusCallback& callback,
+      base::File::Error result);
+
+  content::BrowserContext* context_;
+  WatcherMap watchers_;
+  DispatchEventImplCallback dispatch_event_impl_;
+  GetFileSystemContextImplCallback get_file_system_context_impl_;
+  ScopedObserver<storage::WatcherManager, storage::WatcherManager::Observer>
+      observing_;
+  base::WeakPtrFactory<EntryWatcherService> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(EntryWatcherService);
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_API_FILE_SYSTEM_ENTRY_WATCHER_SERVICE_H_