(For-try) Divide recursive Copy/Move into multiple async tasks

webkit/fileapi/cross_operation_delegate.h

+// Copyright (c) 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.
+
+#ifndef WEBKIT_FILEAPI_CROSS_OPERATION_DELEGATE_H_
+#define WEBKIT_FILEAPI_CROSS_OPERATION_DELEGATE_H_
+
+#include <stack>
+
+#include "base/memory/ref_counted.h"
+#include "webkit/fileapi/recursive_operation_delegate.h"
+
+namespace webkit_blob {
+class ShareableFileReference;
+}
+
+namespace fileapi {
+
+// A delegate class for recursive copy or move operations.
+class CrossOperationDelegate
+    : public RecursiveOperationDelegate,
+      public base::SupportsWeakPtr<CrossOperationDelegate> {
+ public:
+  enum OperationType {
+    OPERATION_COPY,
+    OPERATION_MOVE
+  };
+
+  CrossOperationDelegate(LocalFileSystemOperation* original_operation,
+                         const FileSystemURL& src_root,
+                         const FileSystemURL& dest_root,
+                         OperationType operation_type,
+                         const StatusCallback& callback);
+  virtual ~CrossOperationDelegate();
+
+  // RecursiveOperationDelegate overrides:
+  virtual void Run() OVERRIDE;
+  virtual void RunRecursively() OVERRIDE;
+  virtual void ProcessFile(const FileSystemURL& url,
+                           const StatusCallback& callback) OVERRIDE;
+  virtual void ProcessDirectory(const FileSystemURL& url,
+                                const StatusCallback& callback) OVERRIDE;
+
+  using base::SupportsWeakPtr<CrossOperationDelegate>::AsWeakPtr;
+
+ private:
+  void DidTryCopyOrMoveFile(base::PlatformFileError error);
+  void DidTryRemoveDestRoot(base::PlatformFileError error);
+  void CopyOrMoveFile(
+      const FileSystemURL& src,
+      const FileSystemURL& dest,
+      const StatusCallback& callback);
+  void DidCreateSnapshot(
+      const FileSystemURL& dest,
+      const StatusCallback& callback,
+      base::PlatformFileError error,
+      const base::PlatformFileInfo& file_info,
+      const FilePath& platform_path,
+      const scoped_refptr<webkit_blob::ShareableFileReference>& file_ref);
+  void DidFinishCopy(
+      const FileSystemURL& src,
+      const StatusCallback& callback,
+      base::PlatformFileError error);
+  void DidRemoveSourceForMove(
+      const StatusCallback& callback,
+      base::PlatformFileError error);
+
+  FileSystemURL CreateDestURL(const FileSystemURL& src_url) const;
+
+  // Create nested operations for recursive task.
+  // When creating the operation fails it fires callback_ with the
+  // error code and returns NULL.
+  //
+  // - NewDesetOperation is basically a thin wrapper of
+  //   RecursiveOperationDelegate::NewOperation().
+  //   (Since the original_operation must have been created for the destination
+  //   URL (TODO(kinuko): we should have some assertion for this assumption))
+  //
+  // - NewSourceOperation also redirects the request to
+  //   RecursiveOperationDelegate::NewOperation() **iff** it's for
+  //   same_file_system_ case.
+  //   Otherwise it's for cross-filesystem operation and in needs a
+  //   separate FileSystemOperationContext, so it creates a new operation
+  //   which inherits context from src_root_operation_.
+  //
+  LocalFileSystemOperation* NewSourceOperation(const FileSystemURL& url);
+  LocalFileSystemOperation* NewDestOperation(const FileSystemURL& url);
+
+  FileSystemURL src_root_;
+  FileSystemURL dest_root_;
+  bool same_file_system_;
+  OperationType operation_type_;
+  StatusCallback callback_;
+
+  LocalFileSystemOperation* src_root_operation_;
+
+  scoped_refptr<webkit_blob::ShareableFileReference> current_file_ref_;
+
+  DISALLOW_COPY_AND_ASSIGN(CrossOperationDelegate);
+};
+
+}  // namespace fileapi
+
+#endif  // WEBKIT_FILEAPI_CROSS_OPERATION_DELEGATE_H_