dom/file/FileHelper.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_dom_file_filehelper_h__
   8 #define mozilla_dom_file_filehelper_h__
   9
  10 #include "FileCommon.h"
  11
  12 #include "nsIRequestObserver.h"
  13 #include "nsThreadUtils.h"
  14
  15 class nsIFileStorage;
  16
  17 BEGIN_FILE_NAMESPACE
  18
  19 class FileHelper;
  20 class FileRequest;
  21 class FileOutputStreamWrapper;
  22 class LockedFile;
  23
  24 class FileHelperListener
  25 {
  26 public:
  27   NS_IMETHOD_(nsrefcnt)
  28   AddRef() = 0;
  29
  30   NS_IMETHOD_(nsrefcnt)
  31   Release() = 0;
  32
  33   virtual void
  34   OnFileHelperComplete(FileHelper* aFileHelper) = 0;
  35 };
  36
  37 /**
  38  * Must be subclassed. The subclass must implement DoAsyncRun. It may then
  39  * choose to implement GetSuccessResult to properly set the result of the
  40  * success event. Call Enqueue to start the file operation.
  41  */
  42 class FileHelper : public nsIRequestObserver
  43 {
  44   friend class FileRequest;
  45   friend class FileOutputStreamWrapper;
  46
  47 public:
  48   NS_DECL_ISUPPORTS
  49   NS_DECL_NSIREQUESTOBSERVER
  50
  51   nsresult
  52   Enqueue();
  53
  54   nsresult
  55   AsyncRun(FileHelperListener* aListener);
  56
  57   void
  58   OnStreamProgress(uint64_t aProgress, uint64_t aProgressMax);
  59
  60   void
  61   OnStreamClose()
  62   {
  63     NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
  64     Finish();
  65   }
  66
  67   void
  68   OnStreamDestroy()
  69   {
  70     NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
  71     Finish();
  72   }
  73
  74   static LockedFile*
  75   GetCurrentLockedFile();
  76
  77 protected:
  78   FileHelper(LockedFile* aLockedFile, FileRequest* aRequest);
  79
  80   virtual ~FileHelper();
  81
  82   virtual nsresult
  83   DoAsyncRun(nsISupports* aStream) = 0;
  84
  85   virtual nsresult
  86   GetSuccessResult(JSContext* aCx, JS::Value* aVal);
  87
  88   virtual void
  89   ReleaseObjects();
  90
  91   void
  92   Finish();
  93
  94   nsCOMPtr<nsIFileStorage> mFileStorage;
  95   nsRefPtr<LockedFile> mLockedFile;
  96   nsRefPtr<FileRequest> mFileRequest;
  97
  98   nsRefPtr<FileHelperListener> mListener;
  99   nsCOMPtr<nsIRequest> mRequest;
 100
 101 private:
 102   nsresult mResultCode;
 103   bool mFinished;
 104 };
 105
 106 END_FILE_NAMESPACE
 107
 108 #endif // mozilla_dom_file_filehelper_h__