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nsBufferedStreams.h
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00037 
00038 #ifndef nsBufferedStreams_h__
00039 #define nsBufferedStreams_h__
00040 
00041 #include "nsIBufferedStreams.h"
00042 #include "nsIInputStream.h"
00043 #include "nsIOutputStream.h"
00044 #include "nsISafeOutputStream.h"
00045 #include "nsISeekableStream.h"
00046 #include "nsIStreamBufferAccess.h"
00047 #include "nsCOMPtr.h"
00048 #include "nsInt64.h"
00050 
00051 class nsBufferedStream : public nsISeekableStream
00052 {
00053 public:
00054     NS_DECL_ISUPPORTS
00055     NS_DECL_NSISEEKABLESTREAM
00056 
00057     nsBufferedStream();
00058     virtual ~nsBufferedStream();
00059 
00060     nsresult Close();
00061 
00062 protected:
00063     nsresult Init(nsISupports* stream, PRUint32 bufferSize);
00064     NS_IMETHOD Fill() = 0;
00065     NS_IMETHOD Flush() = 0;
00066 
00067     PRUint32                    mBufferSize;
00068     char*                       mBuffer;
00069 
00070     // mBufferStartOffset is the offset relative to the start of mStream.
00071     nsInt64                     mBufferStartOffset;
00072 
00073     // mCursor is the read cursor for input streams, or write cursor for
00074     // output streams, and is relative to mBufferStartOffset.
00075     PRUint32                    mCursor;
00076 
00077     // mFillPoint is the amount available in the buffer for input streams,
00078     // or the high watermark of bytes written into the buffer, and therefore
00079     // is relative to mBufferStartOffset.
00080     PRUint32                    mFillPoint;
00081 
00082     nsISupports*                mStream;        // cast to appropriate subclass
00083 
00084     PRPackedBool                mBufferDisabled;
00085     PRUint8                     mGetBufferCount;
00086 };
00087 
00089 
00090 class nsBufferedInputStream : public nsBufferedStream,
00091                               public nsIBufferedInputStream,
00092                               public nsIStreamBufferAccess
00093 {
00094 public:
00095     NS_DECL_ISUPPORTS_INHERITED
00096     NS_DECL_NSIINPUTSTREAM
00097     NS_DECL_NSIBUFFEREDINPUTSTREAM
00098     NS_DECL_NSISTREAMBUFFERACCESS
00099 
00100     nsBufferedInputStream() : nsBufferedStream() {}
00101     virtual ~nsBufferedInputStream() {}
00102 
00103     static NS_METHOD
00104     Create(nsISupports *aOuter, REFNSIID aIID, void **aResult);
00105 
00106     nsIInputStream* Source() { 
00107         return (nsIInputStream*)mStream;
00108     }
00109 
00110 protected:
00111     NS_IMETHOD Fill();
00112     NS_IMETHOD Flush() { return NS_OK; } // no-op for input streams
00113 };
00114 
00116 
00117 class nsBufferedOutputStream : public nsBufferedStream, 
00118                                public nsISafeOutputStream,
00119                                public nsIBufferedOutputStream,
00120                                public nsIStreamBufferAccess
00121 {
00122 public:
00123     NS_DECL_ISUPPORTS_INHERITED
00124     NS_DECL_NSIOUTPUTSTREAM
00125     NS_DECL_NSISAFEOUTPUTSTREAM
00126     NS_DECL_NSIBUFFEREDOUTPUTSTREAM
00127     NS_DECL_NSISTREAMBUFFERACCESS
00128 
00129     nsBufferedOutputStream() : nsBufferedStream() {}
00130     virtual ~nsBufferedOutputStream() { nsBufferedOutputStream::Close(); }
00131 
00132     static NS_METHOD
00133     Create(nsISupports *aOuter, REFNSIID aIID, void **aResult);
00134 
00135     nsIOutputStream* Sink() { 
00136         return (nsIOutputStream*)mStream;
00137     }
00138 
00139 protected:
00140     NS_IMETHOD Fill() { return NS_OK; } // no-op for input streams
00141 
00142     nsCOMPtr<nsISafeOutputStream> mSafeStream; // QI'd from mStream
00143 };
00144 
00146 
00147 #endif // nsBufferedStreams_h__