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 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   virtual JSObject* WrapObject(JSContext* aCx,
70                                JS::Handle<JSObject*> aGivenProto) override;
71 
72   // WebIDL
73   static already_AddRefed<FileReader> Constructor(const GlobalObject& aGlobal);
ReadAsArrayBuffer(JSContext * aCx,Blob & aBlob,ErrorResult & aRv)74   void ReadAsArrayBuffer(JSContext* aCx, Blob& aBlob, ErrorResult& aRv) {
75     ReadFileContent(aBlob, EmptyString(), FILE_AS_ARRAYBUFFER, aRv);
76   }
77 
ReadAsText(Blob & aBlob,const Optional<nsAString> & aLabel,ErrorResult & aRv)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 
ReadAsDataURL(Blob & aBlob,ErrorResult & aRv)87   void ReadAsDataURL(Blob& aBlob, ErrorResult& aRv) {
88     ReadFileContent(aBlob, EmptyString(), FILE_AS_DATAURL, aRv);
89   }
90 
91   void Abort();
92 
ReadyState()93   uint16_t ReadyState() const { return static_cast<uint16_t>(mReadyState); }
94 
GetError()95   DOMException* GetError() const { return mError; }
96 
97   void GetResult(JSContext* aCx, Nullable<OwningStringOrArrayBuffer>& aResult);
98 
99   IMPL_EVENT_HANDLER(loadstart)
IMPL_EVENT_HANDLER(progress)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, EmptyString(), 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 
DataFormat()117   eDataFormat DataFormat() const { return mDataFormat; }
Result()118   const nsString& Result() const { return mResult; }
119 
120  private:
121   virtual ~FileReader();
122 
123   // This must be in sync with dom/webidl/FileReader.webidl
124   enum eReadyState { EMPTY = 0, LOADING = 1, DONE = 2 };
125 
126   void RootResultArrayBuffer();
127 
128   void ReadFileContent(Blob& aBlob, const nsAString& aCharset,
129                        eDataFormat aDataFormat, ErrorResult& aRv);
130   nsresult GetAsText(Blob* aBlob, const nsACString& aCharset,
131                      const char* aFileData, uint32_t aDataLen,
132                      nsAString& aResult);
133   nsresult GetAsDataURL(Blob* aBlob, const char* aFileData, uint32_t aDataLen,
134                         nsAString& aResult);
135 
136   void OnLoadEnd(nsresult aStatus);
137 
138   void StartProgressEventTimer();
139   void ClearProgressEventTimer();
140 
141   void FreeDataAndDispatchSuccess();
142   void FreeDataAndDispatchError();
143   void FreeDataAndDispatchError(nsresult aRv);
144   nsresult DispatchProgressEvent(const nsAString& aType);
145 
146   nsresult DoAsyncWait();
147   nsresult DoReadData(uint64_t aCount);
148 
149   void OnLoadEndArrayBuffer();
150 
151   void FreeFileData();
152 
153   nsresult IncreaseBusyCounter();
154   void DecreaseBusyCounter();
155 
156   void Shutdown();
157 
158   char* mFileData;
159   RefPtr<Blob> mBlob;
160   nsCString mCharset;
161   uint32_t mDataLen;
162 
163   eDataFormat mDataFormat;
164 
165   nsString mResult;
166 
167   JS::Heap<JSObject*> mResultArrayBuffer;
168 
169   nsCOMPtr<nsITimer> mProgressNotifier;
170   bool mProgressEventWasDelayed;
171   bool mTimerIsActive;
172 
173   nsCOMPtr<nsIAsyncInputStream> mAsyncStream;
174 
175   RefPtr<DOMException> mError;
176 
177   eReadyState mReadyState;
178 
179   uint64_t mTotal;
180   uint64_t mTransferred;
181 
182   nsCOMPtr<nsIEventTarget> mTarget;
183 
184   uint64_t mBusyCount;
185 
186   // This is set if FileReader is created on workers, but it is null if the
187   // worker is shutting down. The null value is checked in ReadFileContent()
188   // before starting any reading.
189   RefPtr<WeakWorkerRef> mWeakWorkerRef;
190 
191   // This value is set when the reading starts in order to keep the worker alive
192   // during the process.
193   RefPtr<StrongWorkerRef> mStrongWorkerRef;
194 };
195 
196 NS_DEFINE_STATIC_IID_ACCESSOR(FileReader, FILEREADER_ID)
197 
198 }  // namespace dom
199 }  // namespace mozilla
200 
201 #endif  // mozilla_dom_FileReader_h
202