[fsp] First part of support for reading files.

chrome/browser/chromeos/file_system_provider/operations/read_file.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_OPERATIONS_CLOSE_FILE_H_
-#define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_OPERATIONS_CLOSE_FILE_H_
+#ifndef CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_OPERATIONS_READ_FILE_H_
+#define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_OPERATIONS_READ_FILE_H_
 
 #include "base/files/file.h"
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/chromeos/file_system_provider/operations/operation.h"
 #include "chrome/browser/chromeos/file_system_provider/provided_file_system_info.h"
 #include "chrome/browser/chromeos/file_system_provider/provided_file_system_interface.h"
 #include "chrome/browser/chromeos/file_system_provider/request_value.h"
+#include "net/base/io_buffer.h"
 #include "webkit/browser/fileapi/async_file_util.h"
 
 namespace base {
 class FilePath;
 }  // namespace base
 
 namespace extensions {
 class EventRouter;
 }  // namespace extensions
 
 namespace chromeos {
 namespace file_system_provider {
 namespace operations {
 
-// Opens a file for either read or write, with optionally creating the file
-// first. Note, that this is part of fileapi::CreateOrOpen file, but it does
-// not download the file locally. Created per request.
-class CloseFile : public Operation {
+// Bridge between fileapi read file and providing extension's read fil request.
+// Created per request.
+class ReadFile : public Operation {
  public:
-  CloseFile(extensions::EventRouter* event_router,
-            const ProvidedFileSystemInfo& file_system_info,
-            int open_request_id,
-            const fileapi::AsyncFileUtil::StatusCallback& callback);
-  virtual ~CloseFile();
+  ReadFile(
+      extensions::EventRouter* event_router,
+      const ProvidedFileSystemInfo& file_system_info,
+      int file_handle,
+      net::IOBuffer* buffer,
+      int64 offset,
+      int length,
+      const ProvidedFileSystemInterface::ReadChunkReceivedCallback& callback);
+  virtual ~ReadFile();
 
   // Operation overrides.
   virtual bool Execute(int request_id) OVERRIDE;
   virtual void OnSuccess(int request_id,
                          scoped_ptr<RequestValue> result,
                          bool has_next) OVERRIDE;
   virtual void OnError(int request_id, base::File::Error error) OVERRIDE;
 
  private:
-  int open_request_id_;
-  const fileapi::AsyncFileUtil::StatusCallback callback_;
+  int file_handle_;
+  net::IOBuffer* buffer_;
+  int64 offset_;
+  int length_;
+  int64 current_offset_;
+  const ProvidedFileSystemInterface::ReadChunkReceivedCallback callback_;
 
-  DISALLOW_COPY_AND_ASSIGN(CloseFile);
+  DISALLOW_COPY_AND_ASSIGN(ReadFile);
 };
 
 }  // namespace operations
 }  // namespace file_system_provider
 }  // namespace chromeos
 
-#endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_OPERATIONS_CLOSE_FILE_H_
+#endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_OPERATIONS_READ_FILE_H_