dom/file/FileReader.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=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
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_dom_FileReader_h
   8 #define mozilla_dom_FileReader_h
   9
  10 #include "mozilla/Attributes.h"
  11 #include "mozilla/DOMEventTargetHelper.h"
  12
  13 #include "nsIAsyncInputStream.h"
  14 #include "nsIInterfaceRequestor.h"
  15 #include "nsINamed.h"
  16 #include "nsCOMPtr.h"
  17 #include "nsString.h"
  18 #include "nsWeakReference.h"
  19
  20 #define NS_PROGRESS_EVENT_INTERVAL 50
  21
  22 class nsITimer;
  23 class nsIEventTarget;
  24
  25 namespace mozilla {
  26 namespace dom {
  27
  28 class Blob;
  29 class DOMException;
  30 class StrongWorkerRef;
  31 class WeakWorkerRef;
  32
  33 extern const uint64_t kUnknownSize;
  34
  35 class FileReaderDecreaseBusyCounter;
  36
  37 // 26a79031-c94b-47e9-850a-f04fe17bc026
  38 #define FILEREADER_ID                                \
  39   {                                                  \
  40     0x26a79031, 0xc94b, 0x47e9, {                    \
  41       0x85, 0x0a, 0xf0, 0x4f, 0xe1, 0x7b, 0xc0, 0x26 \
  42     }                                                \
  43   }
  44
  45 class FileReader final : public DOMEventTargetHelper,
  46                          public nsIInterfaceRequestor,
  47                          public nsSupportsWeakReference,
  48                          public nsIInputStreamCallback,
  49                          public nsITimerCallback,
  50                          public nsINamed {
  51   friend class FileReaderDecreaseBusyCounter;
  52
  53  public:
  54   FileReader(nsIGlobalObject* aGlobal, WeakWorkerRef* aWorkerRef);
  55
  56   NS_DECL_ISUPPORTS_INHERITED
  57
  58   NS_DECL_NSITIMERCALLBACK
  59   NS_DECL_NSIINPUTSTREAMCALLBACK
  60   NS_DECL_NSIINTERFACEREQUESTOR
  61   NS_DECL_NSINAMED
  62
  63   NS_DECLARE_STATIC_IID_ACCESSOR(FILEREADER_ID)
  64
  65   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(FileReader,
  66                                                          DOMEventTargetHelper)
  67
  68   virtual JSObject* WrapObject(JSContext* aCx,
  69                                JS::Handle<JSObject*> aGivenProto) override;
  70
  71   // WebIDL
  72   static already_AddRefed<FileReader> Constructor(const GlobalObject& aGlobal,
  73                                                   ErrorResult& aRv);
  74   void ReadAsArrayBuffer(JSContext* aCx, Blob& aBlob, ErrorResult& aRv) {
  75     ReadFileContent(aBlob, EmptyString(), FILE_AS_ARRAYBUFFER, aRv);
  76   }
  77
  78   void ReadAsText(Blob& aBlob, const Optional<nsAString>& aLabel,
  79                   ErrorResult& aRv) {
  80     if (aLabel.WasPassed()) {
  81       ReadFileContent(aBlob, aLabel.Value(), FILE_AS_TEXT, aRv);
  82     } else {
  83       ReadFileContent(aBlob, EmptyString(), FILE_AS_TEXT, aRv);
  84     }
  85   }
  86
  87   void ReadAsDataURL(Blob& aBlob, ErrorResult& aRv) {
  88     ReadFileContent(aBlob, EmptyString(), FILE_AS_DATAURL, aRv);
  89   }
  90
  91   void Abort();
  92
  93   uint16_t ReadyState() const { return static_cast<uint16_t>(mReadyState); }
  94
  95   DOMException* GetError() const { return mError; }
  96
  97   void GetResult(JSContext* aCx, JS::MutableHandle<JS::Value> aResult,
  98                  ErrorResult& aRv);
  99
 100   IMPL_EVENT_HANDLER(loadstart)
 101   IMPL_EVENT_HANDLER(progress)
 102   IMPL_EVENT_HANDLER(load)
 103   IMPL_EVENT_HANDLER(abort)
 104   IMPL_EVENT_HANDLER(error)
 105   IMPL_EVENT_HANDLER(loadend)
 106
 107   void ReadAsBinaryString(Blob& aBlob, ErrorResult& aRv) {
 108     ReadFileContent(aBlob, EmptyString(), FILE_AS_BINARY, aRv);
 109   }
 110
 111   enum eDataFormat {
 112     FILE_AS_ARRAYBUFFER,
 113     FILE_AS_BINARY,
 114     FILE_AS_TEXT,
 115     FILE_AS_DATAURL
 116   };
 117
 118   eDataFormat DataFormat() const { return mDataFormat; }
 119   const nsString& Result() const { return mResult; }
 120
 121  private:
 122   virtual ~FileReader();
 123
 124   // This must be in sync with dom/webidl/FileReader.webidl
 125   enum eReadyState { EMPTY = 0, LOADING = 1, DONE = 2 };
 126
 127   void RootResultArrayBuffer();
 128
 129   void ReadFileContent(Blob& aBlob, const nsAString& aCharset,
 130                        eDataFormat aDataFormat, ErrorResult& aRv);
 131   nsresult GetAsText(Blob* aBlob, const nsACString& aCharset,
 132                      const char* aFileData, uint32_t aDataLen,
 133                      nsAString& aResult);
 134   nsresult GetAsDataURL(Blob* aBlob, const char* aFileData, uint32_t aDataLen,
 135                         nsAString& aResult);
 136
 137   nsresult OnLoadEnd(nsresult aStatus);
 138
 139   void StartProgressEventTimer();
 140   void ClearProgressEventTimer();
 141
 142   void FreeDataAndDispatchSuccess();
 143   void FreeDataAndDispatchError();
 144   void FreeDataAndDispatchError(nsresult aRv);
 145   nsresult DispatchProgressEvent(const nsAString& aType);
 146
 147   nsresult DoAsyncWait();
 148   nsresult DoReadData(uint64_t aCount);
 149
 150   void OnLoadEndArrayBuffer();
 151
 152   void FreeFileData();
 153
 154   nsresult IncreaseBusyCounter();
 155   void DecreaseBusyCounter();
 156
 157   void Shutdown();
 158
 159   char* mFileData;
 160   RefPtr<Blob> mBlob;
 161   nsCString mCharset;
 162   uint32_t mDataLen;
 163
 164   eDataFormat mDataFormat;
 165
 166   nsString mResult;
 167
 168   JS::Heap<JSObject*> mResultArrayBuffer;
 169
 170   nsCOMPtr<nsITimer> mProgressNotifier;
 171   bool mProgressEventWasDelayed;
 172   bool mTimerIsActive;
 173
 174   nsCOMPtr<nsIAsyncInputStream> mAsyncStream;
 175
 176   RefPtr<DOMException> mError;
 177
 178   eReadyState mReadyState;
 179
 180   uint64_t mTotal;
 181   uint64_t mTransferred;
 182
 183   nsCOMPtr<nsIEventTarget> mTarget;
 184
 185   uint64_t mBusyCount;
 186
 187   // This is set if FileReader is created on workers, but it is null if the
 188   // worker is shutting down. The null value is checked in ReadFileContent()
 189   // before starting any reading.
 190   RefPtr<WeakWorkerRef> mWeakWorkerRef;
 191
 192   // This value is set when the reading starts in order to keep the worker alive
 193   // during the process.
 194   RefPtr<StrongWorkerRef> mStrongWorkerRef;
 195 };
 196
 197 NS_DEFINE_STATIC_IID_ACCESSOR(FileReader, FILEREADER_ID)
 198
 199 }  // namespace dom
 200 }  // namespace mozilla
 201
 202 #endif  // mozilla_dom_FileReader_h