chrome/browser/chromeos/drive/file_system/truncate_operation.h

   1 // Copyright 2013 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 #ifndef CHROME_BROWSER_CHROMEOS_DRIVE_FILE_SYSTEM_TRUNCATE_OPERATION_H_
   6 #define CHROME_BROWSER_CHROMEOS_DRIVE_FILE_SYSTEM_TRUNCATE_OPERATION_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/memory/weak_ptr.h"
  12 #include "chrome/browser/chromeos/drive/file_errors.h"
  13
  14 namespace base {
  15 class FilePath;
  16 class SequencedTaskRunner;
  17 }  // namespace base
  18
  19 namespace drive {
  20
  21 class JobScheduler;
  22 class ResourceEntry;
  23
  24 namespace internal {
  25 class FileCache;
  26 class ResourceMetadata;
  27 }  // namespace internal
  28
  29 namespace file_system {
  30
  31 class OperationObserver;
  32 class DownloadOperation;
  33
  34 // This class encapsulates the drive Truncate function. It is responsible for
  35 // fetching the content from the Drive server if necessary, truncating the
  36 // file content actually, and then notifying the file is locally modified and
  37 // that it is necessary to upload the file to the server.
  38 class TruncateOperation {
  39  public:
  40   TruncateOperation(base::SequencedTaskRunner* blocking_task_runner,
  41                     OperationObserver* observer,
  42                     JobScheduler* scheduler,
  43                     internal::ResourceMetadata* metadata,
  44                     internal::FileCache* cache,
  45                     const base::FilePath& temporary_file_directory);
  46   ~TruncateOperation();
  47
  48   // Performs the truncate operation on the file at drive path |file_path| to
  49   // |length| bytes. Invokes |callback| when finished with the result of the
  50   // operation. |callback| must not be null.
  51   void Truncate(const base::FilePath& file_path,
  52                 int64 length,
  53                 const FileOperationCallback& callback);
  54  private:
  55   // Part of Truncate(). Called after EnsureFileDownloadedByPath() is complete.
  56   void TruncateAfterEnsureFileDownloadedByPath(
  57       int64 length,
  58       const FileOperationCallback& callback,
  59       FileError error,
  60       const base::FilePath& local_file_path,
  61       scoped_ptr<ResourceEntry> resource_entry);
  62
  63   // Part of Truncate(). Called after TruncateOnBlockingPool() is complete.
  64   void TruncateAfterTruncateOnBlockingPool(
  65       const std::string& local_id,
  66       const FileOperationCallback& callback,
  67       FileError error);
  68
  69   scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
  70   OperationObserver* observer_;
  71   internal::ResourceMetadata* metadata_;
  72   internal::FileCache* cache_;
  73
  74   scoped_ptr<DownloadOperation> download_operation_;
  75
  76   // Note: This should remain the last member so it'll be destroyed and
  77   // invalidate the weak pointers before any other members are destroyed.
  78   base::WeakPtrFactory<TruncateOperation> weak_ptr_factory_;
  79   DISALLOW_COPY_AND_ASSIGN(TruncateOperation);
  80 };
  81
  82 }  // namespace file_system
  83 }  // namespace drive
  84
  85 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_FILE_SYSTEM_TRUNCATE_OPERATION_H_