chrome/browser/extensions/api/image_writer_private/destroy_partitions_operation.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/files/file_util.h"
   6 #include "chrome/browser/extensions/api/image_writer_private/destroy_partitions_operation.h"
   7 #include "chrome/browser/extensions/api/image_writer_private/error_messages.h"
   8 #include "content/public/browser/browser_thread.h"
   9
  10 namespace extensions {
  11 namespace image_writer {
  12
  13 // Number of bytes for the maximum partition table size.  GUID partition tables
  14 // reside in the second sector of the disk.  Disks can have up to 4k sectors.
  15 // See http://crbug.com/328246 for more information.
  16 const int kPartitionTableSize = 2 * 4096;
  17
  18 DestroyPartitionsOperation::DestroyPartitionsOperation(
  19     base::WeakPtr<OperationManager> manager,
  20     const ExtensionId& extension_id,
  21     const std::string& storage_unit_id)
  22     : Operation(manager, extension_id, storage_unit_id) {}
  23
  24 DestroyPartitionsOperation::~DestroyPartitionsOperation() {}
  25
  26 void DestroyPartitionsOperation::StartImpl() {
  27   if (!base::CreateTemporaryFileInDir(temp_dir_.path(), &image_path_)) {
  28     Error(error::kTempFileError);
  29     return;
  30   }
  31
  32   scoped_ptr<char[]> buffer(new char[kPartitionTableSize]);
  33   memset(buffer.get(), 0, kPartitionTableSize);
  34
  35   if (base::WriteFile(image_path_, buffer.get(), kPartitionTableSize) !=
  36       kPartitionTableSize) {
  37     Error(error::kTempFileError);
  38     return;
  39   }
  40
  41   content::BrowserThread::PostTask(
  42       content::BrowserThread::FILE,
  43       FROM_HERE,
  44       base::Bind(&DestroyPartitionsOperation::Write,
  45                  this,
  46                  base::Bind(&DestroyPartitionsOperation::Finish, this)));
  47 }
  48
  49 }  // namespace image_writer
  50 }  // namespace extensions