Wire up Syncable operation runner to the local file sync context

webkit/fileapi/syncable/local_file_sync_context.h

 // Copyright (c) 2012 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 WEBKIT_FILEAPI_SYNCABLE_LOCAL_FILE_SYNC_CONTEXT_H_
 #define WEBKIT_FILEAPI_SYNCABLE_LOCAL_FILE_SYNC_CONTEXT_H_
 
 #include <deque>
 #include <map>
 #include <set>
 
 #include "base/basictypes.h"
-#include "base/callback_forward.h"
+#include "base/callback.h"
 #include "base/file_path.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "googleurl/src/gurl.h"
 #include "webkit/fileapi/syncable/file_change.h"
 #include "webkit/fileapi/syncable/local_file_sync_status.h"
 #include "webkit/fileapi/syncable/sync_status_code.h"
 #include "webkit/storage/webkit_storage_export.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 }
 
 namespace fileapi {
 
 class FileChange;
 class FileSystemContext;
 class LocalFileChangeTracker;
 class SyncableFileOperationRunner;
 
 // This class works as a bridge between LocalFileSyncService (which is a
 // per-profile object) and FileSystemContext's (which is a per-storage-partition
 // object and may exist multiple in a profile).
 // An instance of this class is shared by FileSystemContexts and outlives
 // LocalFileSyncService.
 class WEBKIT_STORAGE_EXPORT LocalFileSyncContext
-    : public base::RefCountedThreadSafe<LocalFileSyncContext> {
+    : public base::RefCountedThreadSafe<LocalFileSyncContext>,
+      public LocalFileSyncStatus::Observer {
  public:
   typedef base::Callback<void(SyncStatusCode status)> StatusCallback;
+  typedef base::Callback<void(const FileSystemURL& url)> URLCallback;
+  typedef base::Callback<void(
+      SyncStatusCode status,
+      const FileChangeList& change)> ChangeListCallback;
 
   LocalFileSyncContext(base::SingleThreadTaskRunner* ui_task_runner,
                        base::SingleThreadTaskRunner* io_task_runner);
 
   // Initializes |file_system_context| for syncable file operations and
   // registers the it into the internal map.
   // Calling this multiple times for the same file_system_context is valid.
   // This method must be called on UI thread.
   void MaybeInitializeFileSystemContext(const GURL& source_url,
                                         FileSystemContext* file_system_context,
                                         const StatusCallback& callback);
 
   // Called when the corresponding LocalFileSyncService exits.
   // This method must be called on UI thread.
   void ShutdownOnUIThread();
 
+  // Prepares for sync |url| by disabling writes on |url|.
+  // If the target |url| is being written and cannot start sync it
+  // returns SYNC_STATUS_WRITING status code via |callback|.
+  // Otherwise it disables writes, marks the |url| syncing and returns
+  // the current change set made on |url|.
+  // This method must be called on UI thread.
+  void PrepareForSync(const FileSystemURL& url,
+                      const ChangeListCallback& callback);
+
+  // Registers |url| to wait until sync is enabled for |url|.
+  // |on_syncable_callback| is to be called when |url| becomes syncable
+  // (i.e. when we have no pending writes and the file is successfully locked
+  // for sync).
+  //
+  // It is NOT valid to call this method while this already has a URL waiting
+  // for sync.
+  //
+  // This method must be called on UI thread.
+  void RegisterURLForWaitingSync(const FileSystemURL& url,
+                                 const URLCallback& on_syncable_callback);
+
   // OperationRunner is accessible only on IO thread.
   base::WeakPtr<SyncableFileOperationRunner> operation_runner() const;
 
   // SyncContext is accessible only on IO thread.
   LocalFileSyncStatus* sync_status() const;
 
+ protected:
+  // LocalFileSyncStatus::Observer overrides. They are called on IO thread.
+  virtual void OnSyncEnabled(const FileSystemURL& url) OVERRIDE;
+  virtual void OnWriteEnabled(const FileSystemURL& url) OVERRIDE;
+
  private:
   typedef std::deque<StatusCallback> StatusCallbackQueue;
   friend class base::RefCountedThreadSafe<LocalFileSyncContext>;
   friend class CannedSyncableFileSystem;
 
   virtual ~LocalFileSyncContext();
 
   void ShutdownOnIOThread();
 
   // Helper routines for MaybeInitializeFileSystemContext.
   void InitializeFileSystemContextOnIOThread(
       const GURL& source_url,
       FileSystemContext* file_system_context);
   SyncStatusCode InitializeChangeTrackerOnFileThread(
       scoped_ptr<LocalFileChangeTracker>* tracker_ptr,
       FileSystemContext* file_system_context);
   void DidInitializeChangeTracker(
       scoped_ptr<LocalFileChangeTracker>* tracker_ptr,
       const GURL& source_url,
       FileSystemContext* file_system_context,
       SyncStatusCode status);
   void DidInitialize(
       const GURL& source_url,
       FileSystemContext* file_system_context,
       SyncStatusCode status);
 
+  // Helper routines for PrepareForSync.
+  void DidDisabledWritesForPrepareForSync(
+      const FileSystemURL& url,
+      const ChangeListCallback& callback);
+
   scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner_;
   scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
 
+  // Indicates if the sync service is shutdown on UI thread.
+  bool shutdown_on_ui_;
+
   // OperationRunner. This must be accessed only on IO thread.
   scoped_ptr<SyncableFileOperationRunner> operation_runner_;
 
   // Keeps track of writing/syncing status.
   // This must be accessed only on IO thread.
   scoped_ptr<LocalFileSyncStatus> sync_status_;
 
   // Pointers to file system contexts that have been initialized for
   // synchronization (i.e. that own this instance).
   // This must be accessed only on UI thread.
   std::set<FileSystemContext*> file_system_contexts_;
 
   // Accessed only on UI thread.
   std::map<FileSystemContext*, StatusCallbackQueue>
       pending_initialize_callbacks_;
 
   // Origin to context map. (Assuming that as far as we're in the same
   // profile single origin wouldn't belong to multiple FileSystemContexts.)
   // Accessed only on UI thread.
   std::map<GURL, FileSystemContext*> origin_to_contexts_;
 
+  // A URL and associated callback waiting for sync is enabled.
+  // Accessed only on IO thread.
+  FileSystemURL url_waiting_sync_on_io_;
+  URLCallback url_syncable_callback_;
+
   DISALLOW_COPY_AND_ASSIGN(LocalFileSyncContext);
 };
 
 }  // namespace fileapi
 
 #endif  // WEBKIT_FILEAPI_SYNCABLE_LOCAL_FILE_SYNC_CONTEXT_H_