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 "nsITimer.h"
  17 #include "nsCOMPtr.h"
  18 #include "nsString.h"
  19 #include "nsWeakReference.h"
  20
  21 #define NS_PROGRESS_EVENT_INTERVAL 50
  22
  23 class nsITimer;
  24 class nsIEventTarget;
  25
  26 namespace mozilla::dom {
  27
  28 class Blob;
  29 class DOMException;
  30 class OwningStringOrArrayBuffer;
  31 class StrongWorkerRef;
  32 class WeakWorkerRef;
  33
  34 extern const uint64_t kUnknownSize;
  35
  36 class FileReaderDecreaseBusyCounter;
  37
  38 // 26a79031-c94b-47e9-850a-f04fe17bc026
  39 #define FILEREADER_ID                                \
  40   {                                                  \
  41     0x26a79031, 0xc94b, 0x47e9, {                    \
  42       0x85, 0x0a, 0xf0, 0x4f, 0xe1, 0x7b, 0xc0, 0x26 \
  43     }                                                \
  44   }
  45
  46 class FileReader final : public DOMEventTargetHelper,
  47                          public nsIInterfaceRequestor,
  48                          public nsSupportsWeakReference,
  49                          public nsIInputStreamCallback,
  50                          public nsITimerCallback,
  51                          public nsINamed {
  52   friend class FileReaderDecreaseBusyCounter;
  53
  54  public:
  55   FileReader(nsIGlobalObject* aGlobal, WeakWorkerRef* aWorkerRef);
  56
  57   NS_DECL_ISUPPORTS_INHERITED
  58
  59   NS_DECL_NSITIMERCALLBACK
  60   NS_DECL_NSIINPUTSTREAMCALLBACK
  61   NS_DECL_NSIINTERFACEREQUESTOR
  62   NS_DECL_NSINAMED
  63
  64   NS_DECLARE_STATIC_IID_ACCESSOR(FILEREADER_ID)
  65
  66   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(FileReader,
  67                                                          DOMEventTargetHelper)
  68
  69   JSObject* WrapObject(JSContext* aCx,
  70                        JS::Handle<JSObject*> aGivenProto) override;
  71
  72   // WebIDL
  73   static already_AddRefed<FileReader> Constructor(const GlobalObject& aGlobal);
  74   void ReadAsArrayBuffer(JSContext* aCx, Blob& aBlob, ErrorResult& aRv) {
  75     ReadFileContent(aBlob, u""_ns, 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, u""_ns, FILE_AS_TEXT, aRv);
  84     }
  85   }
  86
  87   void ReadAsDataURL(Blob& aBlob, ErrorResult& aRv) {
  88     ReadFileContent(aBlob, u""_ns, 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, Nullable<OwningStringOrArrayBuffer>& aResult);
  98
  99   IMPL_EVENT_HANDLER(loadstart)
 100   IMPL_EVENT_HANDLER(progress)
 101   IMPL_EVENT_HANDLER(load)
 102   IMPL_EVENT_HANDLER(abort)
 103   IMPL_EVENT_HANDLER(error)
 104   IMPL_EVENT_HANDLER(loadend)
 105
 106   void ReadAsBinaryString(Blob& aBlob, ErrorResult& aRv) {
 107     ReadFileContent(aBlob, u""_ns, FILE_AS_BINARY, aRv);
 108   }
 109
 110   enum eDataFormat {
 111     FILE_AS_ARRAYBUFFER,
 112     FILE_AS_BINARY,
 113     FILE_AS_TEXT,
 114     FILE_AS_DATAURL
 115   };
 116
 117   eDataFormat DataFormat() const { return mDataFormat; }
 118   const nsString& Result() const { return mResult; }
 119
 120   void InitialAsyncWait();
 121
 122  private:
 123   ~FileReader() override;
 124
 125   // This must be in sync with dom/webidl/FileReader.webidl
 126   enum eReadyState { EMPTY = 0, LOADING = 1, DONE = 2 };
 127
 128   void RootResultArrayBuffer();
 129
 130   void ReadFileContent(Blob& aBlob, const nsAString& aCharset,
 131                        eDataFormat aDataFormat, ErrorResult& aRv);
 132   nsresult GetAsText(Blob* aBlob, const nsACString& aCharset,
 133                      const char* aFileData, uint32_t aDataLen,
 134                      nsAString& aResult);
 135   nsresult GetAsDataURL(Blob* aBlob, const char* aFileData, uint32_t aDataLen,
 136                         nsAString& aResult);
 137
 138   void OnLoadEnd(nsresult aStatus);
 139
 140   void StartProgressEventTimer();
 141   void ClearProgressEventTimer();
 142
 143   void FreeDataAndDispatchSuccess();
 144   void FreeDataAndDispatchError();
 145   void FreeDataAndDispatchError(nsresult aRv);
 146   nsresult DispatchProgressEvent(const nsAString& aType);
 147
 148   nsresult DoAsyncWait();
 149   nsresult DoReadData(uint64_t aCount);
 150
 151   void OnLoadEndArrayBuffer();
 152
 153   void FreeFileData();
 154
 155   nsresult IncreaseBusyCounter();
 156   void DecreaseBusyCounter();
 157
 158   void Cleanup();
 159   void Shutdown();
 160
 161   char* mFileData;
 162   RefPtr<Blob> mBlob;
 163   nsCString mCharset;
 164   uint32_t mDataLen;
 165
 166   eDataFormat mDataFormat;
 167
 168   nsString mResult;
 169
 170   JS::Heap<JSObject*> mResultArrayBuffer;
 171
 172   nsCOMPtr<nsITimer> mProgressNotifier;
 173   bool mProgressEventWasDelayed;
 174   bool mTimerIsActive;
 175
 176   nsCOMPtr<nsIAsyncInputStream> mAsyncStream;
 177
 178   RefPtr<DOMException> mError;
 179
 180   eReadyState mReadyState;
 181
 182   uint64_t mTotal;
 183   uint64_t mTransferred;
 184
 185   nsCOMPtr<nsIEventTarget> mTarget;
 186
 187   uint64_t mBusyCount;
 188
 189   // This is set if FileReader is created on workers, but it is null if the
 190   // worker is shutting down. The null value is checked in ReadFileContent()
 191   // before starting any reading.
 192   RefPtr<WeakWorkerRef> mWeakWorkerRef;
 193
 194   // This value is set when the reading starts in order to keep the worker alive
 195   // during the process.
 196   RefPtr<StrongWorkerRef> mStrongWorkerRef;
 197
 198   // Runnable to start the reading asynchronous.
 199   class AsyncWaitRunnable;
 200   RefPtr<AsyncWaitRunnable> mAsyncWaitRunnable;
 201 };
 202
 203 NS_DEFINE_STATIC_IID_ACCESSOR(FileReader, FILEREADER_ID)
 204
 205 }  // namespace mozilla::dom
 206
 207 #endif  // mozilla_dom_FileReader_h