netwerk/base/nsBufferedStreams.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef nsBufferedStreams_h__
   7 #define nsBufferedStreams_h__
   8
   9 #include "nsIBufferedStreams.h"
  10 #include "nsIInputStream.h"
  11 #include "nsIOutputStream.h"
  12 #include "nsISafeOutputStream.h"
  13 #include "nsISeekableStream.h"
  14 #include "nsIStreamBufferAccess.h"
  15 #include "nsCOMPtr.h"
  16 #include "nsIIPCSerializableInputStream.h"
  17 #include "nsIAsyncInputStream.h"
  18 #include "nsICloneableInputStream.h"
  19 #include "nsIInputStreamLength.h"
  20 #include "mozilla/Mutex.h"
  21 #include "mozilla/RecursiveMutex.h"
  22
  23 ////////////////////////////////////////////////////////////////////////////////
  24
  25 class nsBufferedStream : public nsISeekableStream {
  26  public:
  27   NS_DECL_THREADSAFE_ISUPPORTS
  28   NS_DECL_NSISEEKABLESTREAM
  29   NS_DECL_NSITELLABLESTREAM
  30
  31   nsBufferedStream() = default;
  32
  33   void Close();
  34
  35  protected:
  36   virtual ~nsBufferedStream();
  37
  38   nsresult Init(nsISupports* stream, uint32_t bufferSize);
  39   nsresult GetData(nsISupports** aResult);
  40   NS_IMETHOD Fill() = 0;
  41   NS_IMETHOD Flush() = 0;
  42
  43   uint32_t mBufferSize{0};
  44   char* mBuffer MOZ_GUARDED_BY(mBufferMutex){nullptr};
  45
  46   mozilla::RecursiveMutex mBufferMutex{"nsBufferedStream::mBufferMutex"};
  47
  48   // mBufferStartOffset is the offset relative to the start of mStream.
  49   int64_t mBufferStartOffset{0};
  50
  51   // mCursor is the read cursor for input streams, or write cursor for
  52   // output streams, and is relative to mBufferStartOffset.
  53   uint32_t mCursor{0};
  54
  55   // mFillPoint is the amount available in the buffer for input streams,
  56   // or the high watermark of bytes written into the buffer, and therefore
  57   // is relative to mBufferStartOffset.
  58   uint32_t mFillPoint{0};
  59
  60   nsCOMPtr<nsISupports> mStream;  // cast to appropriate subclass
  61
  62   bool mBufferDisabled{false};
  63   bool mEOF{false};  // True if mStream is at EOF
  64   bool mSeekable{true};
  65   uint8_t mGetBufferCount{0};
  66 };
  67
  68 ////////////////////////////////////////////////////////////////////////////////
  69
  70 class nsBufferedInputStream final : public nsBufferedStream,
  71                                     public nsIBufferedInputStream,
  72                                     public nsIStreamBufferAccess,
  73                                     public nsIIPCSerializableInputStream,
  74                                     public nsIAsyncInputStream,
  75                                     public nsIInputStreamCallback,
  76                                     public nsICloneableInputStream,
  77                                     public nsIInputStreamLength,
  78                                     public nsIAsyncInputStreamLength,
  79                                     public nsIInputStreamLengthCallback {
  80  public:
  81   NS_DECL_ISUPPORTS_INHERITED
  82   NS_DECL_NSIINPUTSTREAM
  83   NS_DECL_NSIBUFFEREDINPUTSTREAM
  84   NS_DECL_NSISTREAMBUFFERACCESS
  85   NS_DECL_NSIIPCSERIALIZABLEINPUTSTREAM
  86   NS_DECL_NSIASYNCINPUTSTREAM
  87   NS_DECL_NSIINPUTSTREAMCALLBACK
  88   NS_DECL_NSICLONEABLEINPUTSTREAM
  89   NS_DECL_NSIINPUTSTREAMLENGTH
  90   NS_DECL_NSIASYNCINPUTSTREAMLENGTH
  91   NS_DECL_NSIINPUTSTREAMLENGTHCALLBACK
  92
  93   nsBufferedInputStream() = default;
  94
  95   static nsresult Create(REFNSIID aIID, void** aResult);
  96
  97   nsIInputStream* Source() { return (nsIInputStream*)mStream.get(); }
  98
  99   /**
 100    * If there's a reference/pointer to an nsBufferedInputStream BEFORE calling
 101    * Init() AND the intent is to ultimately convert/assign that
 102    * reference/pointer to an nsIInputStream, DO NOT use that initial
 103    * reference/pointer. Instead, use the value of QueryInterface-ing to an
 104    * nsIInputStream (and, again, the QueryInterface must be performed after
 105    * Init()). This is because nsBufferedInputStream has multiple underlying
 106    * nsIInputStreams (one from nsIBufferedInputStream and one from
 107    * nsIAsyncInputStream), and the correct base nsIInputStream to use will be
 108    * unknown until the final value of mIsAsyncInputStream is set in Init().
 109    *
 110    * This method, however, does just that but also hides the QI details and
 111    * will assert if called before Init().
 112    */
 113   already_AddRefed<nsIInputStream> GetInputStream();
 114
 115  protected:
 116   virtual ~nsBufferedInputStream() = default;
 117
 118   NS_IMETHOD Fill() override;
 119   NS_IMETHOD Flush() override { return NS_OK; }  // no-op for input streams
 120
 121   mozilla::Mutex mMutex MOZ_UNANNOTATED{"nsBufferedInputStream::mMutex"};
 122
 123   // This value is protected by mutex.
 124   nsCOMPtr<nsIInputStreamCallback> mAsyncWaitCallback;
 125
 126   // This value is protected by mutex.
 127   nsCOMPtr<nsIInputStreamLengthCallback> mAsyncInputStreamLengthCallback;
 128
 129   bool mIsIPCSerializable{true};
 130   bool mIsAsyncInputStream{false};
 131   bool mIsCloneableInputStream{false};
 132   bool mIsInputStreamLength{false};
 133   bool mIsAsyncInputStreamLength{false};
 134 };
 135
 136 ////////////////////////////////////////////////////////////////////////////////
 137
 138 class nsBufferedOutputStream : public nsBufferedStream,
 139                                public nsISafeOutputStream,
 140                                public nsIBufferedOutputStream,
 141                                public nsIStreamBufferAccess {
 142  public:
 143   NS_DECL_ISUPPORTS_INHERITED
 144   NS_DECL_NSIOUTPUTSTREAM
 145   NS_DECL_NSISAFEOUTPUTSTREAM
 146   NS_DECL_NSIBUFFEREDOUTPUTSTREAM
 147   NS_DECL_NSISTREAMBUFFERACCESS
 148
 149   nsBufferedOutputStream() = default;
 150
 151   static nsresult Create(REFNSIID aIID, void** aResult);
 152
 153   nsIOutputStream* Sink() { return (nsIOutputStream*)mStream.get(); }
 154
 155  protected:
 156   virtual ~nsBufferedOutputStream() { nsBufferedOutputStream::Close(); }
 157
 158   NS_IMETHOD Fill() override { return NS_OK; }  // no-op for output streams
 159
 160   nsCOMPtr<nsISafeOutputStream> mSafeStream;  // QI'd from mStream
 161 };
 162
 163 ////////////////////////////////////////////////////////////////////////////////
 164
 165 #endif  // nsBufferedStreams_h__