netwerk/base/src/nsBufferedStreams.h

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  37
  38 #ifndef nsBufferedStreams_h__
  39 #define nsBufferedStreams_h__
  40
  41 #include "nsIBufferedStreams.h"
  42 #include "nsIInputStream.h"
  43 #include "nsIOutputStream.h"
  44 #include "nsISafeOutputStream.h"
  45 #include "nsISeekableStream.h"
  46 #include "nsIStreamBufferAccess.h"
  47 #include "nsCOMPtr.h"
  48 #include "nsInt64.h"
  49 ////////////////////////////////////////////////////////////////////////////////
  50
  51 class nsBufferedStream : public nsISeekableStream
  52 {
  53 public:
  54     NS_DECL_ISUPPORTS
  55     NS_DECL_NSISEEKABLESTREAM
  56
  57     nsBufferedStream();
  58     virtual ~nsBufferedStream();
  59
  60     nsresult Close();
  61
  62 protected:
  63     nsresult Init(nsISupports* stream, PRUint32 bufferSize);
  64     NS_IMETHOD Fill() = 0;
  65     NS_IMETHOD Flush() = 0;
  66
  67     PRUint32                    mBufferSize;
  68     char*                       mBuffer;
  69
  70     // mBufferStartOffset is the offset relative to the start of mStream.
  71     nsInt64                     mBufferStartOffset;
  72
  73     // mCursor is the read cursor for input streams, or write cursor for
  74     // output streams, and is relative to mBufferStartOffset.
  75     PRUint32                    mCursor;
  76
  77     // mFillPoint is the amount available in the buffer for input streams,
  78     // or the high watermark of bytes written into the buffer, and therefore
  79     // is relative to mBufferStartOffset.
  80     PRUint32                    mFillPoint;
  81
  82     nsISupports*                mStream;        // cast to appropriate subclass
  83
  84     PRPackedBool                mBufferDisabled;
  85     PRUint8                     mGetBufferCount;
  86 };
  87
  88 ////////////////////////////////////////////////////////////////////////////////
  89
  90 class nsBufferedInputStream : public nsBufferedStream,
  91                               public nsIBufferedInputStream,
  92                               public nsIStreamBufferAccess
  93 {
  94 public:
  95     NS_DECL_ISUPPORTS_INHERITED
  96     NS_DECL_NSIINPUTSTREAM
  97     NS_DECL_NSIBUFFEREDINPUTSTREAM
  98     NS_DECL_NSISTREAMBUFFERACCESS
  99
 100     nsBufferedInputStream() : nsBufferedStream() {}
 101     virtual ~nsBufferedInputStream() {}
 102
 103     static NS_METHOD
 104     Create(nsISupports *aOuter, REFNSIID aIID, void **aResult);
 105
 106     nsIInputStream* Source() {
 107         return (nsIInputStream*)mStream;
 108     }
 109
 110 protected:
 111     NS_IMETHOD Fill();
 112     NS_IMETHOD Flush() { return NS_OK; } // no-op for input streams
 113 };
 114
 115 ////////////////////////////////////////////////////////////////////////////////
 116
 117 class nsBufferedOutputStream : public nsBufferedStream,
 118                                public nsISafeOutputStream,
 119                                public nsIBufferedOutputStream,
 120                                public nsIStreamBufferAccess
 121 {
 122 public:
 123     NS_DECL_ISUPPORTS_INHERITED
 124     NS_DECL_NSIOUTPUTSTREAM
 125     NS_DECL_NSISAFEOUTPUTSTREAM
 126     NS_DECL_NSIBUFFEREDOUTPUTSTREAM
 127     NS_DECL_NSISTREAMBUFFERACCESS
 128
 129     nsBufferedOutputStream() : nsBufferedStream() {}
 130     virtual ~nsBufferedOutputStream() { nsBufferedOutputStream::Close(); }
 131
 132     static NS_METHOD
 133     Create(nsISupports *aOuter, REFNSIID aIID, void **aResult);
 134
 135     nsIOutputStream* Sink() {
 136         return (nsIOutputStream*)mStream;
 137     }
 138
 139 protected:
 140     NS_IMETHOD Fill() { return NS_OK; } // no-op for input streams
 141
 142     nsCOMPtr<nsISafeOutputStream> mSafeStream; // QI'd from mStream
 143 };
 144
 145 ////////////////////////////////////////////////////////////////////////////////
 146
 147 #endif // nsBufferedStreams_h__