]> git.saurik.com Git - wxWidgets.git/blobdiff - include/wx/stream.h
Make an image block beore writing it, if there's no data in the block
[wxWidgets.git] / include / wx / stream.h
index 25f04afbcca039f977ec578102b1a99407003670..ca3b84eb57ebee606bc297bfab7f9cfb4199697a 100644 (file)
 /////////////////////////////////////////////////////////////////////////////
-// Name:        stream.h
-// Purpose:     "wxWindows stream" base classes
-// Author:      Guilhem Lavaux
+// Name:        wx/stream.h
+// Purpose:     stream classes
+// Author:      Guilhem Lavaux, Guillermo Rodriguez Garcia, Vadim Zeitlin
 // Modified by:
 // Created:     11/07/98
 // RCS-ID:      $Id$
 // Copyright:   (c) Guilhem Lavaux
-// Licence:     wxWindows license
+// Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
 #ifndef _WX_WXSTREAM_H__
 #define _WX_WXSTREAM_H__
 
-#ifdef __GNUG__
-#pragma interface
-#endif
+#include "wx/defs.h"
+
+#if wxUSE_STREAMS
 
 #include <stdio.h>
 #include "wx/object.h"
 #include "wx/string.h"
-#include "wx/filefn.h"  // for off_t, wxInvalidOffset and wxSeekMode
+#include "wx/filefn.h"  // for wxFileOffset, wxInvalidOffset and wxSeekMode
 
-class WXDLLEXPORT wxStreamBase;
-class WXDLLEXPORT wxInputStream;
-class WXDLLEXPORT wxOutputStream;
+class WXDLLIMPEXP_BASE wxStreamBase;
+class WXDLLIMPEXP_BASE wxInputStream;
+class WXDLLIMPEXP_BASE wxOutputStream;
 
 typedef wxInputStream& (*__wxInputManip)(wxInputStream&);
 typedef wxOutputStream& (*__wxOutputManip)(wxOutputStream&);
 
-WXDLLEXPORT wxOutputStream& wxEndL(wxOutputStream& o_stream);
+WXDLLIMPEXP_BASE wxOutputStream& wxEndL(wxOutputStream& o_stream);
+
+// ----------------------------------------------------------------------------
+// constants
+// ----------------------------------------------------------------------------
+
+enum wxStreamError
+{
+    wxSTREAM_NO_ERROR = 0,      // stream is in good state
+    wxSTREAM_EOF,               // EOF reached in Read() or similar
+    wxSTREAM_WRITE_ERROR,       // generic write error
+    wxSTREAM_READ_ERROR         // generic read error
+};
+
+// ============================================================================
+// base stream classes: wxInputStream and wxOutputStream
+// ============================================================================
 
 // ---------------------------------------------------------------------------
-// Stream buffer
+// wxStreamBase: common (but non virtual!) base for all stream classes
 // ---------------------------------------------------------------------------
 
-class WXDLLEXPORT wxStreamBuffer {
- public:
-  typedef enum {
-    read = 0, write, read_write
-  } BufMode;
-
-  // -----------
-  // ctor & dtor
-  // -----------
-  wxStreamBuffer(wxStreamBase& stream, BufMode mode);
-  wxStreamBuffer(BufMode mode);
-  wxStreamBuffer(const wxStreamBuffer& buf);
-  ~wxStreamBuffer();
-
-  // -----------
-  // Filtered IO
-  // -----------
-  size_t Read(void *buffer, size_t size);
-  size_t Read(wxStreamBuffer *buf);
-  size_t Write(const void *buffer, size_t size);
-  size_t Write(wxStreamBuffer *buf);
-
-  size_t WriteBack(const char *buffer, size_t size);
-  bool WriteBack(char c);
-  char GetChar();
-  void PutChar(char c);
-  off_t Tell() const;
-  off_t Seek(off_t pos, wxSeekMode mode);
-
-  // --------------
-  // Buffer control
-  // --------------
-  void ResetBuffer();
-  void SetBufferIO(char *buffer_start, char *buffer_end);
-  void SetBufferIO(size_t bufsize);
-  char *GetBufferStart() const { return m_buffer_start; }
-  char *GetBufferEnd() const { return m_buffer_end; }
-  char *GetBufferPos() const { return m_buffer_pos; }
-  off_t GetIntPosition() const { return m_buffer_pos-m_buffer_start; }
-  void SetIntPosition(off_t pos) { m_buffer_pos = m_buffer_start+pos; }
-  size_t GetLastAccess() const { return m_buffer_end-m_buffer_start; }
-
-  void Fixed(bool fixed) { m_fixed = fixed; }
-  void Flushable(bool f) { m_flushable = f; }
-
-  bool FlushBuffer();
-  bool FillBuffer();
-  size_t GetDataLeft();
-
-  // --------------
-  // Administration
-  // --------------
-  wxStreamBase *Stream() { return m_stream; }
-
- protected:
-  char *AllocSpaceWBack(size_t needed_size);
-  size_t GetWBack(char *buf, size_t bsize);
-
-  void GetFromBuffer(void *buffer, size_t size);
-  void PutToBuffer(const void *buffer, size_t size);
-
- protected:
-  char *m_buffer_start, *m_buffer_end, *m_buffer_pos;
-  size_t m_buffer_size;
-
-  char *m_wback;
-  size_t m_wbacksize, m_wbackcur;
-
-  bool m_fixed, m_flushable;
-
-  wxStreamBase *m_stream;
-  BufMode m_mode;
-  bool m_destroybuf, m_destroystream;
+class WXDLLIMPEXP_BASE wxStreamBase
+{
+public:
+    wxStreamBase();
+    virtual ~wxStreamBase();
+
+    // error testing
+    wxStreamError GetLastError() const { return m_lasterror; }
+    bool IsOk() const { return GetLastError() == wxSTREAM_NO_ERROR; }
+    bool operator!() const { return !IsOk(); }
+
+    // reset the stream state
+    void Reset() { m_lasterror = wxSTREAM_NO_ERROR; }
+
+    // this doesn't make sense for all streams, always test its return value
+    virtual size_t GetSize() const;
+    virtual wxFileOffset GetLength() const { return wxInvalidOffset; }
+
+    // returns true if the streams supports seeking to arbitrary offsets
+    virtual bool IsSeekable() const { return false; }
+
+protected:
+    virtual wxFileOffset OnSysSeek(wxFileOffset seek, wxSeekMode mode);
+    virtual wxFileOffset OnSysTell() const;
+
+    size_t m_lastcount;
+    wxStreamError m_lasterror;
+
+    friend class wxStreamBuffer;
+
+    DECLARE_NO_COPY_CLASS(wxStreamBase)
 };
 
+// ----------------------------------------------------------------------------
+// wxInputStream: base class for the input streams
+// ----------------------------------------------------------------------------
+
+class WXDLLIMPEXP_BASE wxInputStream : public wxStreamBase
+{
+public:
+    // ctor and dtor, nothing exciting
+    wxInputStream();
+    virtual ~wxInputStream();
+
+
+    // IO functions
+    // ------------
+
+    // return a character from the stream without removing it, i.e. it will
+    // still be returned by the next call to GetC()
+    //
+    // blocks until something appears in the stream if necessary, if nothing
+    // ever does (i.e. EOF) LastRead() will return 0 (and the return value is
+    // undefined), otherwise 1
+    virtual char Peek();
+
+    // return one character from the stream, blocking until it appears if
+    // necessary
+    //
+    // if EOF, return value is undefined and LastRead() will return 0 and not 1
+    char GetC();
+
+    // read at most the given number of bytes from the stream
+    //
+    // there are 2 possible situations here: either there is nothing at all in
+    // the stream right now in which case Read() blocks until something appears
+    // (use CanRead() to avoid this) or there is already some data available in
+    // the stream and then Read() doesn't block but returns just the data it
+    // can read without waiting for more
+    //
+    // in any case, if there are not enough bytes in the stream right now,
+    // LastRead() value will be less than size but greater than 0. If it is 0,
+    // it means that EOF has been reached.
+    virtual wxInputStream& Read(void *buffer, size_t size);
+
+    // copy the entire contents of this stream into streamOut, stopping only
+    // when EOF is reached or an error occurs
+    wxInputStream& Read(wxOutputStream& streamOut);
+
+
+    // status functions
+    // ----------------
+
+    // returns the number of bytes read by the last call to Read(), GetC() or
+    // Peek()
+    //
+    // this should be used to discover whether that call succeeded in reading
+    // all the requested data or not
+    virtual size_t LastRead() const { return wxStreamBase::m_lastcount; }
+
+    // returns true if some data is available in the stream right now, so that
+    // calling Read() wouldn't block
+    virtual bool CanRead() const;
+
+    // is the stream at EOF?
+    //
+    // note that this cannot be really implemented for all streams and
+    // CanRead() is more reliable than Eof()
+    virtual bool Eof() const;
+
+
+    // write back buffer
+    // -----------------
+
+    // put back the specified number of bytes into the stream, they will be
+    // fetched by the next call to the read functions
+    //
+    // returns the number of bytes really stuffed back
+    size_t Ungetch(const void *buffer, size_t size);
+
+    // put back the specified character in the stream
+    //
+    // returns true if ok, false on error
+    bool Ungetch(char c);
+
+
+    // position functions
+    // ------------------
+
+    // move the stream pointer to the given position (if the stream supports
+    // it)
+    //
+    // returns wxInvalidOffset on error
+    virtual wxFileOffset SeekI(wxFileOffset pos, wxSeekMode mode = wxFromStart);
+
+    // return the current position of the stream pointer or wxInvalidOffset
+    virtual wxFileOffset TellI() const;
+
+
+    // stream-like operators
+    // ---------------------
+
+    wxInputStream& operator>>(wxOutputStream& out) { return Read(out); }
+    wxInputStream& operator>>(__wxInputManip func) { return func(*this); }
+
+protected:
+    // do read up to size bytes of data into the provided buffer
+    //
+    // this method should return 0 if EOF has been reached or an error occurred
+    // (m_lasterror should be set accordingly as well) or the number of bytes
+    // read
+    virtual size_t OnSysRead(void *buffer, size_t size) = 0;
+
+    // write-back buffer support
+    // -------------------------
+
+    // return the pointer to a buffer big enough to hold sizeNeeded bytes
+    char *AllocSpaceWBack(size_t sizeNeeded);
+
+    // read up to size data from the write back buffer, return the number of
+    // bytes read
+    size_t GetWBack(void *buf, size_t size);
+
+    // write back buffer or NULL if none
+    char *m_wback;
+
+    // the size of the buffer
+    size_t m_wbacksize;
+
+    // the current position in the buffer
+    size_t m_wbackcur;
+
+    friend class wxStreamBuffer;
+
+    DECLARE_NO_COPY_CLASS(wxInputStream)
+};
+
+// ----------------------------------------------------------------------------
+// wxOutputStream: base for the output streams
+// ----------------------------------------------------------------------------
+
+class WXDLLIMPEXP_BASE wxOutputStream : public wxStreamBase
+{
+public:
+    wxOutputStream();
+    virtual ~wxOutputStream();
+
+    void PutC(char c);
+    virtual wxOutputStream& Write(const void *buffer, size_t size);
+    wxOutputStream& Write(wxInputStream& stream_in);
+
+    virtual wxFileOffset SeekO(wxFileOffset pos, wxSeekMode mode = wxFromStart);
+    virtual wxFileOffset TellO() const;
+
+    virtual size_t LastWrite() const { return wxStreamBase::m_lastcount; }
+
+    virtual void Sync();
+    virtual bool Close() { return true; }
+
+    wxOutputStream& operator<<(wxInputStream& out) { return Write(out); }
+    wxOutputStream& operator<<( __wxOutputManip func) { return func(*this); }
+
+protected:
+    // to be implemented in the derived classes (it should have been pure
+    // virtual)
+    virtual size_t OnSysWrite(const void *buffer, size_t bufsize);
+
+    friend class wxStreamBuffer;
+
+    DECLARE_NO_COPY_CLASS(wxOutputStream)
+};
+
+// ============================================================================
+// helper stream classes
+// ============================================================================
+
 // ---------------------------------------------------------------------------
-// wxStream: base classes
+// A stream for measuring streamed output
 // ---------------------------------------------------------------------------
 
-typedef enum {
-  wxStream_NOERROR = 0,
-  wxStream_EOF,
-  wxStream_WRITE_ERR,
-  wxStream_READ_ERR
-} wxStreamError;
+class WXDLLIMPEXP_BASE wxCountingOutputStream : public wxOutputStream
+{
+public:
+    wxCountingOutputStream();
 
-class WXDLLEXPORT wxStreamBase {
- public:
-  wxStreamBase();
-  virtual ~wxStreamBase();
+    wxFileOffset GetLength() const;
+    bool Ok() const { return true; }
 
-  wxStreamError LastError() const { return m_lasterror; }
-  virtual size_t StreamSize() const { return ~((size_t)0); }
+protected:
+    virtual size_t OnSysWrite(const void *buffer, size_t size);
+    virtual wxFileOffset OnSysSeek(wxFileOffset pos, wxSeekMode mode);
+    virtual wxFileOffset OnSysTell() const;
 
- protected:
-  friend class wxStreamBuffer;
+    size_t m_currentPos;
 
-  virtual size_t OnSysRead(void *buffer, size_t bufsize);
-  virtual size_t OnSysWrite(const void *buffer, size_t bufsize);
-  virtual off_t OnSysSeek(off_t seek, wxSeekMode mode);
-  virtual off_t OnSysTell() const;
+    DECLARE_NO_COPY_CLASS(wxCountingOutputStream)
+};
 
- protected:
-  size_t m_lastcount;
-  wxStreamError m_lasterror;
+// ---------------------------------------------------------------------------
+// "Filter" streams
+// ---------------------------------------------------------------------------
+
+class WXDLLIMPEXP_BASE wxFilterInputStream : public wxInputStream
+{
+public:
+    wxFilterInputStream();
+    wxFilterInputStream(wxInputStream& stream);
+    virtual ~wxFilterInputStream();
+
+    char Peek() { return m_parent_i_stream->Peek(); }
+
+    wxFileOffset GetLength() const { return m_parent_i_stream->GetLength(); }
+
+    wxInputStream *GetFilterInputStream() const { return m_parent_i_stream; }
+
+protected:
+    wxInputStream *m_parent_i_stream;
+
+    DECLARE_NO_COPY_CLASS(wxFilterInputStream)
 };
 
-class WXDLLEXPORT wxInputStream: public wxStreamBase {
- public:
-  wxInputStream();
-  wxInputStream(wxStreamBuffer *sbuf);
-  virtual ~wxInputStream();
-
-  // IO functions
-  virtual char Peek();
-  char GetC();
-  wxInputStream& Read(void *buffer, size_t size);
-  wxInputStream& Read(wxOutputStream& stream_out);
-
-  // Position functions
-  off_t SeekI(off_t pos, wxSeekMode mode = wxFromStart);
-  off_t TellI() const;
-
-  // State functions
-  wxStreamBuffer *InputStreamBuffer() { return m_i_streambuf; }
-  size_t LastRead() { return wxStreamBase::m_lastcount; }
-
-  // Operators
-  wxInputStream& operator>>(wxOutputStream& out) { return Read(out); }
-  wxInputStream& operator>>(wxString& line);
-  wxInputStream& operator>>(char& c);
-  wxInputStream& operator>>(short& i);
-  wxInputStream& operator>>(int& i);
-  wxInputStream& operator>>(long& i);
-  wxInputStream& operator>>(double& i);
-#if wxUSE_SERIAL
-  wxInputStream& operator>>(wxObject *& obj);
-#endif
-
-  wxInputStream& operator>>(float& f) { double d; operator>>((double&)d); f = (float)d; return *this; }
-  wxInputStream& operator>>(unsigned char& c) { return operator>>((char&)c); }
-  wxInputStream& operator>>(unsigned short& i) { return operator>>((short&)i); }
-  wxInputStream& operator>>(unsigned int& i) { return operator>>((int&)i); }
-  wxInputStream& operator>>(unsigned long& i) { return operator>>((long&)i); }
-  wxInputStream& operator>>( __wxInputManip func) { return func(*this); }
-
- protected:
-  bool m_i_destroybuf;
-  wxStreamBuffer *m_i_streambuf;
+class WXDLLIMPEXP_BASE wxFilterOutputStream : public wxOutputStream
+{
+public:
+    wxFilterOutputStream();
+    wxFilterOutputStream(wxOutputStream& stream);
+    virtual ~wxFilterOutputStream();
+
+    wxFileOffset GetLength() const { return m_parent_o_stream->GetLength(); }
+
+    wxOutputStream *GetFilterOutputStream() const { return m_parent_o_stream; }
+
+protected:
+    wxOutputStream *m_parent_o_stream;
+
+    DECLARE_NO_COPY_CLASS(wxFilterOutputStream)
 };
 
-class WXDLLEXPORT wxOutputStream: public wxStreamBase {
- public:
-  wxOutputStream();
-  wxOutputStream(wxStreamBuffer *sbuf);
-  virtual ~wxOutputStream();
-
-  wxOutputStream& Write(const void *buffer, size_t size);
-  wxOutputStream& Write(wxInputStream& stream_in);
-
-  off_t SeekO(off_t pos, wxSeekMode mode = wxFromStart);
-  off_t TellO() const;
-
-  size_t LastWrite() const { return wxStreamBase::m_lastcount; }
-  wxStreamBuffer *OutputStreamBuffer() { return m_o_streambuf; }
-
-  void Sync();
-
-  wxOutputStream& operator<<(wxInputStream& out) { return Write(out); }
-  wxOutputStream& operator<<(const char *string);
-  wxOutputStream& operator<<(wxString& string);
-  wxOutputStream& operator<<(char c);
-  wxOutputStream& operator<<(short i);
-  wxOutputStream& operator<<(int i);
-  wxOutputStream& operator<<(long i);
-  wxOutputStream& operator<<(double f);
-#if wxUSE_SERIAL
-  wxOutputStream& operator<<(wxObject& obj);
-#endif
-
-  wxOutputStream& operator<<(float f) { return operator<<((double)f); }
-  wxOutputStream& operator<<(unsigned char c) { return operator<<((char)c); }
-  wxOutputStream& operator<<(unsigned short i) { return operator<<((short)i); }
-  wxOutputStream& operator<<(unsigned int i) { return operator<<((int)i); }
-  wxOutputStream& operator<<(unsigned long i) { return operator<<((long)i); }
-  wxOutputStream& operator<<( __wxOutputManip func) { return func(*this); }
-
- protected:
-  bool m_o_destroybuf;
-  wxStreamBuffer *m_o_streambuf;
+// ============================================================================
+// buffered streams
+// ============================================================================
+
+// ---------------------------------------------------------------------------
+// Stream buffer: this class can be derived from and passed to
+// wxBufferedStreams to implement custom buffering
+// ---------------------------------------------------------------------------
+
+class WXDLLIMPEXP_BASE wxStreamBuffer
+{
+public:
+    enum BufMode
+    {
+        read,
+        write,
+        read_write
+    };
+
+    wxStreamBuffer(wxStreamBase& stream, BufMode mode);
+    wxStreamBuffer(const wxStreamBuffer& buf);
+    virtual ~wxStreamBuffer();
+
+    // Filtered IO
+    virtual size_t Read(void *buffer, size_t size);
+    size_t Read(wxStreamBuffer *buf);
+    virtual size_t Write(const void *buffer, size_t size);
+    size_t Write(wxStreamBuffer *buf);
+
+    virtual char Peek();
+    virtual char GetChar();
+    virtual void PutChar(char c);
+    virtual wxFileOffset Tell() const;
+    virtual wxFileOffset Seek(wxFileOffset pos, wxSeekMode mode);
+
+    // Buffer control
+    void ResetBuffer();
+
+    // NB: the buffer must always be allocated with malloc() if takeOwn is
+    //     true as it will be deallocated by free()
+    void SetBufferIO(void *start, void *end, bool takeOwnership = false);
+    void SetBufferIO(void *start, size_t len, bool takeOwnership = false);
+    void SetBufferIO(size_t bufsize);
+    void *GetBufferStart() const { return m_buffer_start; }
+    void *GetBufferEnd() const { return m_buffer_end; }
+    void *GetBufferPos() const { return m_buffer_pos; }
+    size_t GetBufferSize() const { return m_buffer_size; }
+    size_t GetIntPosition() const { return m_buffer_pos - m_buffer_start; }
+    void SetIntPosition(size_t pos) { m_buffer_pos = m_buffer_start + pos; }
+    size_t GetLastAccess() const { return m_buffer_end - m_buffer_start; }
+    size_t GetBytesLeft() const { return m_buffer_end - m_buffer_pos; }
+
+    void Fixed(bool fixed) { m_fixed = fixed; }
+    void Flushable(bool f) { m_flushable = f; }
+
+    bool FlushBuffer();
+    bool FillBuffer();
+    size_t GetDataLeft();
+
+    // misc accessors
+    wxStreamBase *GetStream() const { return m_stream; }
+    bool HasBuffer() const { return m_buffer_size != 0; }
+
+    bool IsFixed() const { return m_fixed; }
+    bool IsFlushable() const { return m_flushable; }
+
+    // only for input/output buffers respectively, returns NULL otherwise
+    wxInputStream *GetInputStream() const;
+    wxOutputStream *GetOutputStream() const;
+
+#if WXWIN_COMPATIBILITY_2_6
+    // deprecated, for compatibility only
+    wxDEPRECATED( wxStreamBase *Stream() );
+#endif // WXWIN_COMPATIBILITY_2_6
+
+    // this constructs a dummy wxStreamBuffer, used by (and exists for)
+    // wxMemoryStreams only, don't use!
+    wxStreamBuffer(BufMode mode);
+
+protected:
+    void GetFromBuffer(void *buffer, size_t size);
+    void PutToBuffer(const void *buffer, size_t size);
+
+    // set the last error to the specified value if we didn't have it before
+    void SetError(wxStreamError err);
+
+    // common part of several ctors
+    void Init();
+
+    // init buffer variables to be empty
+    void InitBuffer();
+
+    // free the buffer (always safe to call)
+    void FreeBuffer();
+
+    // the buffer itself: the pointers to its start and end and the current
+    // position in the buffer
+    char *m_buffer_start,
+         *m_buffer_end,
+         *m_buffer_pos;
+
+    // the buffer size
+    // FIXME: isn't it the same as m_buffer_end - m_buffer_start? (VZ)
+    size_t m_buffer_size;
+
+    // the stream we're associated with
+    wxStreamBase *m_stream;
+
+    // its mode
+    BufMode m_mode;
+
+    // flags
+    bool m_destroybuf,      // deallocate buffer?
+         m_fixed,
+         m_flushable;
+
+private:
+// Cannot use
+//  DECLARE_NO_COPY_CLASS(wxStreamBuffer)
+// because copy constructor is explicitly declared above;
+// but no copy assignment operator is defined, so declare
+// it private to prevent the compiler from defining it:
+    wxStreamBuffer& operator=(const wxStreamBuffer&);
 };
 
 // ---------------------------------------------------------------------------
-// "Filter" streams
+// wxBufferedInputStream
 // ---------------------------------------------------------------------------
 
-class WXDLLEXPORT wxFilterInputStream: public wxInputStream {
- public:
-  wxFilterInputStream();
-  wxFilterInputStream(wxInputStream& stream);
-  ~wxFilterInputStream();
+class WXDLLIMPEXP_BASE wxBufferedInputStream : public wxFilterInputStream
+{
+public:
+    // if a non NULL buffer is given to the stream, it will be deleted by it
+    wxBufferedInputStream(wxInputStream& stream,
+                          wxStreamBuffer *buffer = NULL);
+    virtual ~wxBufferedInputStream();
+
+    char Peek();
+    wxInputStream& Read(void *buffer, size_t size);
+
+    // Position functions
+    wxFileOffset SeekI(wxFileOffset pos, wxSeekMode mode = wxFromStart);
+    wxFileOffset TellI() const;
+    bool IsSeekable() const { return m_parent_i_stream->IsSeekable(); }
+
+    // the buffer given to the stream will be deleted by it
+    void SetInputStreamBuffer(wxStreamBuffer *buffer);
+    wxStreamBuffer *GetInputStreamBuffer() const { return m_i_streambuf; }
+
+#if WXWIN_COMPATIBILITY_2_6
+    // deprecated, for compatibility only
+    wxDEPRECATED( wxStreamBuffer *InputStreamBuffer() const );
+#endif // WXWIN_COMPATIBILITY_2_6
 
-  char Peek() { return m_parent_i_stream->Peek(); }
+protected:
+    virtual size_t OnSysRead(void *buffer, size_t bufsize);
+    virtual wxFileOffset OnSysSeek(wxFileOffset seek, wxSeekMode mode);
+    virtual wxFileOffset OnSysTell() const;
 
-  wxStreamError LastError() const { return m_parent_i_stream->LastError(); }
-  size_t StreamSize() const { return m_parent_i_stream->StreamSize(); }
+    wxStreamBuffer *m_i_streambuf;
 
- protected:
-  wxInputStream *m_parent_i_stream;
+    DECLARE_NO_COPY_CLASS(wxBufferedInputStream)
 };
 
-class WXDLLEXPORT wxFilterOutputStream: public wxOutputStream {
- public:
-  wxFilterOutputStream();
-  wxFilterOutputStream(wxOutputStream& stream);
-  ~wxFilterOutputStream();
+// ----------------------------------------------------------------------------
+// wxBufferedOutputStream
+// ----------------------------------------------------------------------------
 
-  wxStreamError LastError() const { return m_parent_o_stream->LastError(); }
-  size_t StreamSize() const { return m_parent_o_stream->StreamSize(); }
+class WXDLLIMPEXP_BASE wxBufferedOutputStream : public wxFilterOutputStream
+{
+public:
+    // if a non NULL buffer is given to the stream, it will be deleted by it
+    wxBufferedOutputStream(wxOutputStream& stream,
+                           wxStreamBuffer *buffer = NULL);
+    virtual ~wxBufferedOutputStream();
 
- protected:
-  wxOutputStream *m_parent_o_stream;
+    wxOutputStream& Write(const void *buffer, size_t size);
+
+    // Position functions
+    wxFileOffset SeekO(wxFileOffset pos, wxSeekMode mode = wxFromStart);
+    wxFileOffset TellO() const;
+    bool IsSeekable() const { return m_parent_o_stream->IsSeekable(); }
+
+    void Sync();
+    bool Close();
+
+    wxFileOffset GetLength() const;
+
+    // the buffer given to the stream will be deleted by it
+    void SetOutputStreamBuffer(wxStreamBuffer *buffer);
+    wxStreamBuffer *GetOutputStreamBuffer() const { return m_o_streambuf; }
+
+#if WXWIN_COMPATIBILITY_2_6
+    // deprecated, for compatibility only
+    wxDEPRECATED( wxStreamBuffer *OutputStreamBuffer() const );
+#endif // WXWIN_COMPATIBILITY_2_6
+
+protected:
+    virtual size_t OnSysWrite(const void *buffer, size_t bufsize);
+    virtual wxFileOffset OnSysSeek(wxFileOffset seek, wxSeekMode mode);
+    virtual wxFileOffset OnSysTell() const;
+
+    wxStreamBuffer *m_o_streambuf;
+
+    DECLARE_NO_COPY_CLASS(wxBufferedOutputStream)
 };
 
-#endif
+#if WXWIN_COMPATIBILITY_2_6
+    inline wxStreamBase *wxStreamBuffer::Stream() { return m_stream; }
+    inline wxStreamBuffer *wxBufferedInputStream::InputStreamBuffer() const { return m_i_streambuf; }
+    inline wxStreamBuffer *wxBufferedOutputStream::OutputStreamBuffer() const { return m_o_streambuf; }
+#endif // WXWIN_COMPATIBILITY_2_6
+
+#endif // wxUSE_STREAMS
+
+#endif // _WX_WXSTREAM_H__