xpcom/io/InputStreamLengthWrapper.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 InputStreamLengthWrapper_h
   8 #define InputStreamLengthWrapper_h
   9
  10 #include "mozilla/Attributes.h"
  11 #include "mozilla/Mutex.h"
  12 #include "nsCOMPtr.h"
  13 #include "nsIAsyncInputStream.h"
  14 #include "nsICloneableInputStream.h"
  15 #include "nsIIPCSerializableInputStream.h"
  16 #include "nsISeekableStream.h"
  17 #include "nsIInputStreamLength.h"
  18
  19 namespace mozilla {
  20
  21 // A wrapper keeps an inputStream together with its length.
  22 // This class can be used for nsIInputStreams that do not implement
  23 // nsIInputStreamLength.
  24
  25 class InputStreamLengthWrapper final : public nsIAsyncInputStream,
  26                                        public nsICloneableInputStream,
  27                                        public nsIIPCSerializableInputStream,
  28                                        public nsISeekableStream,
  29                                        public nsIInputStreamCallback,
  30                                        public nsIInputStreamLength {
  31  public:
  32   NS_DECL_THREADSAFE_ISUPPORTS
  33   NS_DECL_NSIINPUTSTREAM
  34   NS_DECL_NSIASYNCINPUTSTREAM
  35   NS_DECL_NSICLONEABLEINPUTSTREAM
  36   NS_DECL_NSIIPCSERIALIZABLEINPUTSTREAM
  37   NS_DECL_NSISEEKABLESTREAM
  38   NS_DECL_NSITELLABLESTREAM
  39   NS_DECL_NSIINPUTSTREAMCALLBACK
  40   NS_DECL_NSIINPUTSTREAMLENGTH
  41
  42   // This method creates a InputStreamLengthWrapper around aInputStream if
  43   // this doesn't implement nsIInputStreamLength or
  44   // nsIInputStreamAsyncLength interface, but it implements
  45   // nsIAsyncInputStream. For this kind of streams,
  46   // InputStreamLengthHelper is not able to retrieve the length. This
  47   // method will make such streams ready to be used with
  48   // InputStreamLengthHelper.
  49   static already_AddRefed<nsIInputStream> MaybeWrap(
  50       already_AddRefed<nsIInputStream> aInputStream, int64_t aLength);
  51
  52   // The length here will be used when nsIInputStreamLength::Length() is called.
  53   InputStreamLengthWrapper(already_AddRefed<nsIInputStream> aInputStream,
  54                            int64_t aLength);
  55
  56   // This CTOR is meant to be used just for IPC.
  57   InputStreamLengthWrapper();
  58
  59  private:
  60   ~InputStreamLengthWrapper();
  61
  62   void SetSourceStream(already_AddRefed<nsIInputStream> aInputStream);
  63
  64   nsCOMPtr<nsIInputStream> mInputStream;
  65
  66   // Raw pointers because these are just QI of mInputStream.
  67   nsICloneableInputStream* mWeakCloneableInputStream;
  68   nsIIPCSerializableInputStream* mWeakIPCSerializableInputStream;
  69   nsISeekableStream* mWeakSeekableInputStream;
  70   nsITellableStream* mWeakTellableInputStream;
  71   nsIAsyncInputStream* mWeakAsyncInputStream;
  72
  73   int64_t mLength;
  74   bool mConsumed;
  75
  76   mozilla::Mutex mMutex;
  77
  78   // This is used for AsyncWait and it's protected by mutex.
  79   nsCOMPtr<nsIInputStreamCallback> mAsyncWaitCallback MOZ_GUARDED_BY(mMutex);
  80 };
  81
  82 }  // namespace mozilla
  83
  84 #endif  // InputStreamLengthWrapper_h