storage/browser/fileapi/file_observers.h

   1 // Copyright (c) 2012 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 STORAGE_BROWSER_FILEAPI_FILE_OBSERVERS_H_
   6 #define STORAGE_BROWSER_FILEAPI_FILE_OBSERVERS_H_
   7
   8 #include "base/basictypes.h"
   9 #include "storage/browser/storage_browser_export.h"
  10
  11 // TODO(kinuko): Split this file into per-observer multiple files.
  12
  13 namespace storage {
  14
  15 class FileSystemURL;
  16
  17 // An abstract interface to observe update operations.
  18 //
  19 // OnStartUpdate and OnEndUpdate are called once for each target url
  20 // before and after following operations regardless of whether the operation
  21 // is made recursively or not (i.e. StartUpdate() will be called only once
  22 // for destination url regardless of whether it is recursive copy or not):
  23 //  CreateFile(), CreateDirectory(),
  24 //  Copy() (destination only),
  25 //  Move() (both for source and destination),
  26 //  Remove(), Write(), Truncate(), TouchFile()
  27 //
  28 // OnUpdate() is called each time the |url| is updated but works only for
  29 // sandboxed files (where usage is tracked).
  30 class STORAGE_EXPORT FileUpdateObserver {
  31  public:
  32   FileUpdateObserver() {}
  33   virtual ~FileUpdateObserver() {}
  34
  35   virtual void OnStartUpdate(const FileSystemURL& url) = 0;
  36   virtual void OnUpdate(const FileSystemURL& url, int64 delta) = 0;
  37   virtual void OnEndUpdate(const FileSystemURL& url) = 0;
  38
  39  private:
  40   DISALLOW_COPY_AND_ASSIGN(FileUpdateObserver);
  41 };
  42
  43 // An abstract interface to observe file access.
  44 // OnAccess is called whenever an operation reads file contents or metadata.
  45 // (It is called only once per operation regardless of whether the operation
  46 // is recursive or not)
  47 class STORAGE_EXPORT FileAccessObserver {
  48  public:
  49   FileAccessObserver() {}
  50   virtual ~FileAccessObserver() {}
  51
  52   virtual void OnAccess(const FileSystemURL& url) = 0;
  53
  54  private:
  55   DISALLOW_COPY_AND_ASSIGN(FileAccessObserver);
  56 };
  57
  58 // An abstract interface to observe file changes.
  59 // Each method of this class is called once per file/directory is created,
  60 // removed or modified.  For recursive operations each method is called for
  61 // each subdirectory/subfile.  Currently ChangeObserver is only supported
  62 // by the local sandbox file system.
  63 class STORAGE_EXPORT FileChangeObserver {
  64  public:
  65   FileChangeObserver() {}
  66   virtual ~FileChangeObserver() {}
  67
  68   virtual void OnCreateFile(const FileSystemURL& url) = 0;
  69   virtual void OnCreateFileFrom(const FileSystemURL& url,
  70                                 const FileSystemURL& src) = 0;
  71   virtual void OnRemoveFile(const FileSystemURL& url) = 0;
  72   virtual void OnModifyFile(const FileSystemURL& url) = 0;
  73
  74   virtual void OnCreateDirectory(const FileSystemURL& url) = 0;
  75   virtual void OnRemoveDirectory(const FileSystemURL& url) = 0;
  76
  77  private:
  78   DISALLOW_COPY_AND_ASSIGN(FileChangeObserver);
  79 };
  80
  81 }  // namespace storage
  82
  83 #endif  // STORAGE_BROWSER_FILEAPI_FILE_OBSERVERS_H_