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fixing overrelease and out-of-bounds write, fixes #13725
[wxWidgets.git] / src / common / stream.cpp
diff --git a/src/common/stream.cpp b/src/common/stream.cpp
index dda5f6446bee5ba0e264eb2fb20d85bd4655cdf6..f7cd2ea2c58db63aa52248adc2857100f501c1e5 100644 (file)
--- a/src/common/stream.cpp
+++ b/src/common/stream.cpp
@@ -1,603 +1,1537 @@
 /////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////
-// Name:        stream.cpp
+// Name:        src/common/stream.cpp
 // Purpose:     wxStream base classes
 // Author:      Guilhem Lavaux
 // Purpose:     wxStream base classes
 // Author:      Guilhem Lavaux
-// Modified by:
+// Modified by: VZ (23.11.00) to fix realloc()ing new[]ed memory,
+//                            general code review
 // Created:     11/07/98
 // RCS-ID:      $Id$
 // Copyright:   (c) Guilhem Lavaux
 // Created:     11/07/98
 // RCS-ID:      $Id$
 // Copyright:   (c) Guilhem Lavaux
-// Licence:     wxWindows license
+// Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
 /////////////////////////////////////////////////////////////////////////////
 
-#ifdef __GNUG__
-#pragma implementation "stream.h"
-#endif
+// ============================================================================
+// declarations
+// ============================================================================
+
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------
 
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
-#include <ctype.h>
-#include <wx/stream.h>
-#include <wx/datstrm.h>
-#include <wx/objstrm.h>
 
 #ifdef __BORLANDC__
 
 #ifdef __BORLANDC__
-#pragma hdrstop
+    #pragma hdrstop
 #endif
 
 #endif
 
+#if wxUSE_STREAMS
+
+#include "wx/stream.h"
+
+#ifndef WX_PRECOMP
+    #include "wx/log.h"
+#endif
+
+#include <ctype.h>
+#include "wx/datstrm.h"
+#include "wx/textfile.h"
+#include "wx/scopeguard.h"
+
+// ----------------------------------------------------------------------------
+// constants
+// ----------------------------------------------------------------------------
+
+// the temporary buffer size used when copying from stream to stream
+#define BUF_TEMP_SIZE 4096
+
+// ============================================================================
+// implementation
+// ============================================================================
+
 // ----------------------------------------------------------------------------
 // wxStreamBuffer
 // ----------------------------------------------------------------------------
 
 // ----------------------------------------------------------------------------
 // wxStreamBuffer
 // ----------------------------------------------------------------------------
 
-wxStreamBuffer::wxStreamBuffer(wxInputStream& i_stream)
-  : m_buffer_start(NULL), m_buffer_end(NULL), m_buffer_pos(NULL),
-    m_buffer_size(0), m_istream(&i_stream), m_ostream(NULL)
+void wxStreamBuffer::SetError(wxStreamError err)
 {
 {
+   if ( m_stream && m_stream->m_lasterror == wxSTREAM_NO_ERROR )
+       m_stream->m_lasterror = err;
 }
 
 }
 
-wxStreamBuffer::wxStreamBuffer(wxOutputStream& o_stream)
-  : m_buffer_start(NULL), m_buffer_end(NULL), m_buffer_pos(NULL),
-    m_buffer_size(0), m_istream(NULL), m_ostream(&o_stream)
+void wxStreamBuffer::InitBuffer()
 {
 {
+    m_buffer_start =
+    m_buffer_end =
+    m_buffer_pos = NULL;
+
+    // if we are going to allocate the buffer, we should free it later as well
+    m_destroybuf = true;
 }
 
 }
 
-wxStreamBuffer::~wxStreamBuffer()
+void wxStreamBuffer::Init()
 {
 {
-  wxDELETEA(m_buffer_start);
+    InitBuffer();
+
+    m_fixed = true;
 }
 
 }
 
-void wxStreamBuffer::WriteBack(char c)
+void wxStreamBuffer::InitWithStream(wxStreamBase& stream, BufMode mode)
 {
 {
-  if (m_ostream)
-    return;
+    Init();
 
 
-  // Assume that if we write "back" we have read a few bytes: so we have some
-  // space.
+    m_stream = &stream;
+    m_mode = mode;
 
 
-  m_buffer_pos--;
-  *m_buffer_pos = c;
+    m_flushable = true;
 }
 
 }
 
-void wxStreamBuffer::SetBufferIO(char *buffer_start, char *buffer_end)
+wxStreamBuffer::wxStreamBuffer(BufMode mode)
 {
 {
-  size_t ret;
+    Init();
 
 
-  m_buffer_start = buffer_start;
-  m_buffer_end   = buffer_end;
+    m_stream = NULL;
+    m_mode = mode;
 
 
-  m_buffer_size = m_buffer_end-m_buffer_start;
+    m_flushable = false;
+}
 
 
-  if (m_istream) {
-    ret = m_istream->DoRead(m_buffer_start, m_buffer_size);
-    m_buffer_end = m_buffer_start + ret;
-  }
-  m_buffer_pos = m_buffer_start;
+wxStreamBuffer::wxStreamBuffer(const wxStreamBuffer& buffer)
+{
+    // doing this has big chances to lead to a crash when the source buffer is
+    // destroyed (otherwise assume the caller knows what he does)
+    wxASSERT_MSG( !buffer.m_destroybuf,
+                  wxT("it's a bad idea to copy this buffer") );
+
+    m_buffer_start = buffer.m_buffer_start;
+    m_buffer_end = buffer.m_buffer_end;
+    m_buffer_pos = buffer.m_buffer_pos;
+    m_fixed = buffer.m_fixed;
+    m_flushable = buffer.m_flushable;
+    m_stream = buffer.m_stream;
+    m_mode = buffer.m_mode;
+    m_destroybuf = false;
 }
 
 }
 
-void wxStreamBuffer::SetBufferIO(size_t bufsize)
+void wxStreamBuffer::FreeBuffer()
 {
 {
-  char *b_start;
+    if ( m_destroybuf )
+    {
+        free(m_buffer_start);
+        m_buffer_start = NULL;
+    }
+}
 
 
-  wxDELETE(m_buffer_start);
+wxStreamBuffer::~wxStreamBuffer()
+{
+    FreeBuffer();
+}
 
 
-  if (!bufsize) {
-    m_buffer_start = NULL;
-    m_buffer_end = NULL;
-    m_buffer_pos = NULL;
-    m_buffer_size = 0;
-    return;
-  }
+wxInputStream *wxStreamBuffer::GetInputStream() const
+{
+    return m_mode == write ? NULL : (wxInputStream *)m_stream;
+}
+
+wxOutputStream *wxStreamBuffer::GetOutputStream() const
+{
+    return m_mode == read ? NULL : (wxOutputStream *)m_stream;
+}
+
+void wxStreamBuffer::SetBufferIO(void *buffer_start,
+                                 void *buffer_end,
+                                 bool takeOwnership)
+{
+    SetBufferIO(buffer_start, (char *)buffer_end - (char *)buffer_start,
+                takeOwnership);
+}
 
 
-  b_start = new char[bufsize];
+void wxStreamBuffer::SetBufferIO(void *start,
+                                 size_t len,
+                                 bool takeOwnership)
+{
+    // start by freeing the old buffer
+    FreeBuffer();
+
+    m_buffer_start = (char *)start;
+    m_buffer_end   = m_buffer_start + len;
+
+    // if we own it, we free it
+    m_destroybuf = takeOwnership;
 
 
-  SetBufferIO(b_start, b_start + bufsize);
+    ResetBuffer();
+}
+
+void wxStreamBuffer::SetBufferIO(size_t bufsize)
+{
+    if ( bufsize )
+    {
+        // this will free the old buffer and allocate the new one
+        SetBufferIO(malloc(bufsize), bufsize, true /* take ownership */);
+    }
+    else // no buffer size => no buffer
+    {
+        // still free the old one
+        FreeBuffer();
+        InitBuffer();
+    }
 }
 
 void wxStreamBuffer::ResetBuffer()
 {
 }
 
 void wxStreamBuffer::ResetBuffer()
 {
-  if (m_istream)
+    if ( m_stream )
+    {
+        m_stream->Reset();
+        m_stream->m_lastcount = 0;
+    }
+
+    m_buffer_pos = m_mode == read && m_flushable
+                        ? m_buffer_end
+                        : m_buffer_start;
+}
+
+void wxStreamBuffer::Truncate()
+{
+    size_t new_size = m_buffer_pos - m_buffer_start;
+    if ( m_buffer_pos == m_buffer_end )
+        return;
+
+    if ( !new_size )
+    {
+        FreeBuffer();
+        InitBuffer();
+        return;
+    }
+
+    char *new_start = (char *)realloc(m_buffer_start, new_size);
+    wxCHECK_RET( new_size, wxT("shrinking buffer shouldn't fail") );
+
+    m_buffer_start = new_start;
+    m_buffer_end = m_buffer_start + new_size;
     m_buffer_pos = m_buffer_end;
     m_buffer_pos = m_buffer_end;
-  else
+}
+
+// fill the buffer with as much data as possible (only for read buffers)
+bool wxStreamBuffer::FillBuffer()
+{
+    wxInputStream *inStream = GetInputStream();
+
+    // It's legal to have no stream, so we don't complain about it just return false
+    if ( !inStream )
+        return false;
+
+    size_t count = inStream->OnSysRead(GetBufferStart(), GetBufferSize());
+    if ( !count )
+        return false;
+
+    m_buffer_end = m_buffer_start + count;
     m_buffer_pos = m_buffer_start;
     m_buffer_pos = m_buffer_start;
+
+    return true;
 }
 
 }
 
-void wxStreamBuffer::Read(void *buffer, size_t size)
+// write the buffer contents to the stream (only for write buffers)
+bool wxStreamBuffer::FlushBuffer()
 {
 {
-  wxASSERT(m_istream != NULL);
+    wxCHECK_MSG( m_flushable, false, wxT("can't flush this buffer") );
 
 
-  // ------------------
-  // Buffering disabled
-  // ------------------
+    // FIXME: what is this check for? (VZ)
+    if ( m_buffer_pos == m_buffer_start )
+        return false;
 
 
-  if (!m_buffer_size) {
-    m_istream->m_lastread = m_istream->DoRead(buffer, size);
-    return;
-  }
+    wxOutputStream *outStream = GetOutputStream();
 
 
-  // -----------------
-  // Buffering enabled
-  // -----------------
-  size_t buf_left, orig_size = size;
-  size_t read_ret;
+    wxCHECK_MSG( outStream, false, wxT("should have a stream in wxStreamBuffer") );
 
 
-  while (size > 0) {
-    buf_left = m_buffer_end - m_buffer_pos; 
+    size_t current = m_buffer_pos - m_buffer_start;
+    size_t count = outStream->OnSysWrite(m_buffer_start, current);
+    if ( count != current )
+        return false;
 
 
-    // First case: the requested buffer is larger than the stream buffer,
-    //             we split
-    if (size > buf_left) {
-      memcpy(buffer, m_buffer_pos, buf_left);
-      size -= buf_left;
-      buffer = (char *)buffer + buf_left; // ANSI C++ violation.
+    m_buffer_pos = m_buffer_start;
 
 
-      read_ret = m_istream->DoRead(m_buffer_start, m_buffer_size);
+    return true;
+}
 
 
-      // Read failed: EOF
-      if (read_ret == 0) {
-        m_istream->m_lastread = orig_size-size;
-        m_istream->m_eof = TRUE;
-        m_buffer_pos = m_buffer_end = m_buffer_start;
-        return;
-      } else {
-        m_buffer_end = m_buffer_start+read_ret;
-        m_buffer_pos = m_buffer_start;
-      }
-    } else {
+size_t wxStreamBuffer::GetDataLeft()
+{
+    /* Why is this done? RR. */
+    if ( m_buffer_pos == m_buffer_end && m_flushable)
+        FillBuffer();
 
 
-      // Second case: we just copy from the stream buffer.
-      memcpy(buffer, m_buffer_pos, size);
-      m_buffer_pos += size;
-      break;
+    return GetBytesLeft();
+}
+
+// copy up to size bytes from our buffer into the provided one
+void wxStreamBuffer::GetFromBuffer(void *buffer, size_t size)
+{
+    // don't get more bytes than left in the buffer
+    size_t left = GetBytesLeft();
+
+    if ( size > left )
+        size = left;
+
+    memcpy(buffer, m_buffer_pos, size);
+    m_buffer_pos += size;
+}
+
+// copy the contents of the provided buffer into this one
+void wxStreamBuffer::PutToBuffer(const void *buffer, size_t size)
+{
+    size_t left = GetBytesLeft();
+
+    if ( size > left )
+    {
+        if ( m_fixed )
+        {
+            // we can't realloc the buffer, so just copy what we can
+            size = left;
+        }
+        else // !m_fixed
+        {
+            // realloc the buffer to have enough space for the data
+            if ( m_buffer_pos + size > m_buffer_end )
+            {
+                size_t delta = m_buffer_pos - m_buffer_start;
+                size_t new_size = delta + size;
+
+                char *startOld = m_buffer_start;
+                m_buffer_start = (char *)realloc(m_buffer_start, new_size);
+                if ( !m_buffer_start )
+                {
+                    // don't leak memory if realloc() failed
+                    m_buffer_start = startOld;
+
+                    // what else can we do?
+                    return;
+                }
+
+                // adjust the pointers invalidated by realloc()
+                m_buffer_pos = m_buffer_start + delta;
+                m_buffer_end = m_buffer_start + new_size;
+            } // else: the buffer is big enough
+        }
     }
     }
-  }
-  m_istream->m_lastread = orig_size;
+
+    memcpy(m_buffer_pos, buffer, size);
+    m_buffer_pos += size;
 }
 
 }
 
-void wxStreamBuffer::Write(const void *buffer, size_t size)
+void wxStreamBuffer::PutChar(char c)
 {
 {
-  wxASSERT(m_ostream != NULL);
+    wxOutputStream *outStream = GetOutputStream();
 
 
-  // ------------------
-  // Buffering disabled
-  // ------------------
+    wxCHECK_RET( outStream, wxT("should have a stream in wxStreamBuffer") );
+
+    // if we don't have buffer at all, just forward this call to the stream,
+    if ( !HasBuffer() )
+    {
+        outStream->OnSysWrite(&c, sizeof(c));
+    }
+    else
+    {
+        // otherwise check we have enough space left
+        if ( !GetDataLeft() && !FlushBuffer() )
+        {
+            // we don't
+            SetError(wxSTREAM_WRITE_ERROR);
+        }
+        else
+        {
+            PutToBuffer(&c, sizeof(c));
+            m_stream->m_lastcount = 1;
+        }
+    }
+}
 
 
-  if (!m_buffer_size) {
-    m_ostream->m_lastwrite = m_ostream->DoWrite(buffer, size);
-    return;
-  }
+char wxStreamBuffer::Peek()
+{
+    wxCHECK_MSG( m_stream && HasBuffer(), 0,
+                 wxT("should have the stream and the buffer in wxStreamBuffer") );
 
 
-  // ------------------
-  // Buffering enabled
-  // ------------------
+    if ( !GetDataLeft() )
+    {
+        SetError(wxSTREAM_READ_ERROR);
+        return 0;
+    }
 
 
-  size_t buf_left, orig_size = size;
-  size_t write_ret;
+    char c;
+    GetFromBuffer(&c, sizeof(c));
+    m_buffer_pos--;
 
 
-  while (size > 0) {
-    buf_left = m_buffer_end - m_buffer_pos;
+    return c;
+}
 
 
-    // First case: the buffer to write is larger than the stream buffer,
-    //             we split it
-    if (size > buf_left) {
-      memcpy(m_buffer_pos, buffer, buf_left);
-      size -= buf_left;
-      buffer = (char *)buffer + buf_left; // ANSI C++ violation.
+char wxStreamBuffer::GetChar()
+{
+    wxInputStream *inStream = GetInputStream();
 
 
-      write_ret = m_ostream->DoWrite(m_buffer_start, m_buffer_size);
-      if (write_ret != m_buffer_size) {
-        m_ostream->m_bad = TRUE;
-        m_ostream->m_lastwrite = orig_size-size;
-        m_buffer_pos = m_buffer_end = m_buffer_start;
-        return;
-      }
-      m_buffer_pos = m_buffer_start;
+    wxCHECK_MSG( inStream, 0, wxT("should have a stream in wxStreamBuffer") );
 
 
-    } else {
+    char c;
+    if ( !HasBuffer() )
+    {
+        inStream->OnSysRead(&c, sizeof(c));
+    }
+    else
+    {
+        if ( !GetDataLeft() )
+        {
+            SetError(wxSTREAM_READ_ERROR);
+            c = 0;
+        }
+        else
+        {
+            GetFromBuffer(&c, sizeof(c));
+            m_stream->m_lastcount = 1;
+        }
+    }
+
+    return c;
+}
+
+size_t wxStreamBuffer::Read(void *buffer, size_t size)
+{
+    wxASSERT_MSG( buffer, wxT("Warning: Null pointer is about to be used") );
 
 
-      // Second case: just copy it in the stream buffer.
+    /* Clear buffer first */
+    memset(buffer, 0x00, size);
 
 
-      memcpy(m_buffer_pos, buffer, size);
-      m_buffer_pos += size;
-      break;
+    // lasterror is reset before all new IO calls
+    if ( m_stream )
+        m_stream->Reset();
+
+    size_t readBytes;
+    if ( !HasBuffer() )
+    {
+        wxInputStream *inStream = GetInputStream();
+
+        wxCHECK_MSG( inStream, 0, wxT("should have a stream in wxStreamBuffer") );
+
+        readBytes = inStream->OnSysRead(buffer, size);
     }
     }
-  }
-  m_ostream->m_lastwrite = orig_size;
+    else // we have a buffer, use it
+    {
+        size_t orig_size = size;
+
+        while ( size > 0 )
+        {
+            size_t left = GetDataLeft();
+
+            // if the requested number of bytes if greater than the buffer
+            // size, read data in chunks
+            if ( size > left )
+            {
+                GetFromBuffer(buffer, left);
+                size -= left;
+                buffer = (char *)buffer + left;
+
+                if ( !FillBuffer() )
+                {
+                    SetError(wxSTREAM_EOF);
+                    break;
+                }
+            }
+            else // otherwise just do it in one gulp
+            {
+                GetFromBuffer(buffer, size);
+                size = 0;
+            }
+        }
+
+        readBytes = orig_size - size;
+    }
+
+    if ( m_stream )
+        m_stream->m_lastcount = readBytes;
+
+    return readBytes;
 }
 
 }
 
-// ----------------------------------------------------------------------------
-// wxInputStream
-// ----------------------------------------------------------------------------
+// this should really be called "Copy()"
+size_t wxStreamBuffer::Read(wxStreamBuffer *dbuf)
+{
+    wxCHECK_MSG( m_mode != write, 0, wxT("can't read from this buffer") );
+
+    char buf[BUF_TEMP_SIZE];
+    size_t nRead,
+           total = 0;
+
+    do
+    {
+        nRead = Read(buf, WXSIZEOF(buf));
+        if ( nRead )
+        {
+            nRead = dbuf->Write(buf, nRead);
+            total += nRead;
+        }
+    }
+    while ( nRead );
 
 
-wxInputStream::wxInputStream()
+    return total;
+}
+
+size_t wxStreamBuffer::Write(const void *buffer, size_t size)
 {
 {
-  m_i_destroybuf = TRUE;
-  m_i_streambuf = new wxStreamBuffer(*this);
-  m_eof = FALSE;
+    wxASSERT_MSG( buffer, wxT("Warning: Null pointer is about to be send") );
+
+    if (m_stream)
+    {
+        // lasterror is reset before all new IO calls
+        m_stream->Reset();
+    }
+
+    size_t ret;
+
+    if ( !HasBuffer() && m_fixed )
+    {
+        wxOutputStream *outStream = GetOutputStream();
+
+        wxCHECK_MSG( outStream, 0, wxT("should have a stream in wxStreamBuffer") );
+
+        // no buffer, just forward the call to the stream
+        ret = outStream->OnSysWrite(buffer, size);
+    }
+    else // we [may] have a buffer, use it
+    {
+        size_t orig_size = size;
+
+        while ( size > 0 )
+        {
+            size_t left = GetBytesLeft();
+
+            // if the buffer is too large to fit in the stream buffer, split
+            // it in smaller parts
+            //
+            // NB: If stream buffer isn't fixed (as for wxMemoryOutputStream),
+            //     we always go to the second case.
+            //
+            // FIXME: fine, but if it fails we should (re)try writing it by
+            //        chunks as this will (hopefully) always work (VZ)
+
+            if ( size > left && m_fixed )
+            {
+                PutToBuffer(buffer, left);
+                size -= left;
+                buffer = (char *)buffer + left;
+
+                if ( !FlushBuffer() )
+                {
+                    SetError(wxSTREAM_WRITE_ERROR);
+
+                    break;
+                }
+
+                m_buffer_pos = m_buffer_start;
+            }
+            else // we can do it in one gulp
+            {
+                PutToBuffer(buffer, size);
+                size = 0;
+            }
+        }
+
+        ret = orig_size - size;
+    }
+
+    if (m_stream)
+    {
+        // i am not entirely sure what we do this for
+        m_stream->m_lastcount = ret;
+    }
+
+    return ret;
 }
 
 }
 
-wxInputStream::wxInputStream(wxStreamBuffer *buffer)
+size_t wxStreamBuffer::Write(wxStreamBuffer *sbuf)
 {
 {
-  m_i_destroybuf = FALSE;
-  m_i_streambuf = buffer;
-  m_eof = FALSE;
+    wxCHECK_MSG( m_mode != read, 0, wxT("can't write to this buffer") );
+    wxCHECK_MSG( sbuf->m_mode != write, 0, wxT("can't read from that buffer") );
+
+    char buf[BUF_TEMP_SIZE];
+    size_t nWrite,
+           total = 0;
+
+    do
+    {
+        size_t nRead = sbuf->Read(buf, WXSIZEOF(buf));
+        if ( nRead )
+        {
+            nWrite = Write(buf, nRead);
+            if ( nWrite < nRead )
+            {
+                // put back data we couldn't copy
+                wxInputStream *in_stream = (wxInputStream *)sbuf->GetStream();
+
+                in_stream->Ungetch(buf + nWrite, nRead - nWrite);
+            }
+
+            total += nWrite;
+        }
+        else
+        {
+            nWrite = 0;
+        }
+    }
+    while ( nWrite == WXSIZEOF(buf) );
+
+    return total;
 }
 
 }
 
-wxInputStream::~wxInputStream()
+wxFileOffset wxStreamBuffer::Seek(wxFileOffset pos, wxSeekMode mode)
 {
 {
-  if (m_i_destroybuf)
-    delete m_i_streambuf;
+    wxFileOffset ret_off, diff;
+
+    wxFileOffset last_access = GetLastAccess();
+
+    if ( !m_flushable )
+    {
+        switch (mode)
+        {
+            case wxFromStart:
+                diff = pos;
+                break;
+
+            case wxFromCurrent:
+                diff = pos + GetIntPosition();
+                break;
+
+            case wxFromEnd:
+                diff = pos + last_access;
+                break;
+
+            default:
+                wxFAIL_MSG( wxT("invalid seek mode") );
+
+                return wxInvalidOffset;
+        }
+        if (diff < 0 || diff > last_access)
+            return wxInvalidOffset;
+        size_t int_diff = wx_truncate_cast(size_t, diff);
+        wxCHECK_MSG( (wxFileOffset)int_diff == diff, wxInvalidOffset, wxT("huge file not supported") );
+        SetIntPosition(int_diff);
+        return diff;
+    }
+
+    switch ( mode )
+    {
+        case wxFromStart:
+            // We'll try to compute an internal position later ...
+            ret_off = m_stream->OnSysSeek(pos, wxFromStart);
+            ResetBuffer();
+            return ret_off;
+
+        case wxFromCurrent:
+            diff = pos + GetIntPosition();
+
+            if ( (diff > last_access) || (diff < 0) )
+            {
+                // We must take into account the fact that we have read
+                // something previously.
+                ret_off = m_stream->OnSysSeek(diff-last_access, wxFromCurrent);
+                ResetBuffer();
+                return ret_off;
+            }
+            else
+            {
+                size_t int_diff = wx_truncate_cast(size_t, diff);
+                wxCHECK_MSG( (wxFileOffset)int_diff == diff, wxInvalidOffset, wxT("huge file not supported") );
+                SetIntPosition(int_diff);
+                return diff;
+            }
+
+        case wxFromEnd:
+            // Hard to compute: always seek to the requested position.
+            ret_off = m_stream->OnSysSeek(pos, wxFromEnd);
+            ResetBuffer();
+            return ret_off;
+    }
+
+    return wxInvalidOffset;
 }
 
 }
 
-char wxInputStream::GetC()
+wxFileOffset wxStreamBuffer::Tell() const
 {
 {
-  char c;
-  m_i_streambuf->Read(&c, 1);
-  return c;
+    wxFileOffset pos;
+
+    // ask the stream for position if we have a real one
+    if ( m_stream )
+    {
+        pos = m_stream->OnSysTell();
+        if ( pos == wxInvalidOffset )
+            return wxInvalidOffset;
+    }
+    else // no associated stream
+    {
+        pos = 0;
+    }
+
+    pos += GetIntPosition();
+
+    if ( m_mode == read && m_flushable )
+        pos -= GetLastAccess();
+
+    return pos;
 }
 
 }
 
-wxInputStream& wxInputStream::Read(void *buffer, size_t size)
+// ----------------------------------------------------------------------------
+// wxStreamBase
+// ----------------------------------------------------------------------------
+
+IMPLEMENT_ABSTRACT_CLASS(wxStreamBase, wxObject)
+
+wxStreamBase::wxStreamBase()
 {
 {
-  m_i_streambuf->Read(buffer, size);
-  // wxStreamBuffer sets all variables for us
-  return *this;
+    m_lasterror = wxSTREAM_NO_ERROR;
+    m_lastcount = 0;
 }
 
 }
 
-#define BUF_TEMP_SIZE 10000
+wxStreamBase::~wxStreamBase()
+{
+}
 
 
-wxInputStream& wxInputStream::Read(wxOutputStream& stream_out)
+size_t wxStreamBase::GetSize() const
 {
 {
-  char buf[BUF_TEMP_SIZE]; 
-  size_t bytes_read = BUF_TEMP_SIZE;
+    wxFileOffset length = GetLength();
+    if ( length == (wxFileOffset)wxInvalidOffset )
+        return 0;
 
 
-  while (bytes_read == BUF_TEMP_SIZE && !stream_out.Bad()) {
-    bytes_read = Read(buf, bytes_read).LastRead();
+    const size_t len = wx_truncate_cast(size_t, length);
+    wxASSERT_MSG( len == length + size_t(0), wxT("large files not supported") );
 
 
-    stream_out.Write(buf, bytes_read);
-  }
-  return *this;
+    return len;
 }
 
 }
 
-wxInputStream& wxInputStream::operator>>(wxString& line)
+wxFileOffset wxStreamBase::OnSysSeek(wxFileOffset WXUNUSED(seek), wxSeekMode WXUNUSED(mode))
 {
 {
-  wxDataInputStream s(*this);
+    return wxInvalidOffset;
+}
 
 
-  line = s.ReadLine();
-  return *this;
+wxFileOffset wxStreamBase::OnSysTell() const
+{
+    return wxInvalidOffset;
 }
 
 }
 
-wxInputStream& wxInputStream::operator>>(char& c)
+// ----------------------------------------------------------------------------
+// wxInputStream
+// ----------------------------------------------------------------------------
+
+IMPLEMENT_ABSTRACT_CLASS(wxInputStream, wxStreamBase)
+
+wxInputStream::wxInputStream()
 {
 {
-  c = GetC();
-  return *this;
+    m_wback = NULL;
+    m_wbacksize =
+    m_wbackcur = 0;
 }
 
 }
 
-wxInputStream& wxInputStream::operator>>(short& i)
+wxInputStream::~wxInputStream()
 {
 {
-  long l;
+    free(m_wback);
+}
 
 
-  *this >> l;
-  i = (short)l;
-  return *this;
+bool wxInputStream::CanRead() const
+{
+    // we don't know if there is anything to read or not and by default we
+    // prefer to be optimistic and try to read data unless we know for sure
+    // there is no more of it
+    return m_lasterror != wxSTREAM_EOF;
+}
+
+bool wxInputStream::Eof() const
+{
+    // the only way the base class can know we're at EOF is when we'd already
+    // tried to read beyond it in which case last error is set accordingly
+    return GetLastError() == wxSTREAM_EOF;
 }
 
 }
 
-wxInputStream& wxInputStream::operator>>(int& i)
+char *wxInputStream::AllocSpaceWBack(size_t needed_size)
 {
 {
-  long l;
+    // get number of bytes left from previous wback buffer
+    size_t toget = m_wbacksize - m_wbackcur;
+
+    // allocate a buffer large enough to hold prev + new data
+    char *temp_b = (char *)malloc(needed_size + toget);
+
+    if (!temp_b)
+        return NULL;
 
 
-  *this >> l;
-  i = (short)l;
-  return *this;
+    // copy previous data (and free old buffer) if needed
+    if (m_wback)
+    {
+        memmove(temp_b + needed_size, m_wback + m_wbackcur, toget);
+        free(m_wback);
+    }
+
+    // done
+    m_wback = temp_b;
+    m_wbackcur = 0;
+    m_wbacksize = needed_size + toget;
+
+    return m_wback;
 }
 
 }
 
-wxInputStream& wxInputStream::operator>>(long& i)
+size_t wxInputStream::GetWBack(void *buf, size_t size)
 {
 {
-  /* I only implemented a simple integer parser */
-  int c, sign;
+    wxASSERT_MSG( buf, wxT("Warning: Null pointer is about to be used") );
 
 
-  while (isspace( c = GetC() ) )
-     /* Do nothing */ ;
+    /* Clear buffer first */
+    memset(buf, 0x00, size);
 
 
-  i = 0;
-  if (! (c == '-' || isdigit(c)) ) {
-    InputStreamBuffer()->WriteBack(c);
-    return *this;
-  }
+    if (!m_wback)
+        return 0;
 
 
-  if (c == '-') {
-    sign = -1;
-    c = GetC();
-  } else
-    sign = 1;
+    // how many bytes do we have in the buffer?
+    size_t toget = m_wbacksize - m_wbackcur;
 
 
-  while (isdigit(c)) {
-    i = i*10 + c;
-    c = GetC();
-  }
+    if ( size < toget )
+    {
+        // we won't read everything
+        toget = size;
+    }
 
 
-  i *= sign;
+    // copy the data from the cache
+    memcpy(buf, m_wback + m_wbackcur, toget);
+
+    m_wbackcur += toget;
+    if ( m_wbackcur == m_wbacksize )
+    {
+        // TODO: should we really free it here all the time? maybe keep it?
+        free(m_wback);
+        m_wback = NULL;
+        m_wbacksize = 0;
+        m_wbackcur = 0;
+    }
 
 
-  return *this;
+    // return the number of bytes copied
+    return toget;
 }
 
 }
 
-wxInputStream& wxInputStream::operator>>(float& f)
+size_t wxInputStream::Ungetch(const void *buf, size_t bufsize)
 {
 {
-  /* I only implemented a simple float parser */
-  int c, sign;
+    wxASSERT_MSG( buf, wxT("Warning: Null pointer is about to be used in Ungetch()") );
 
 
-  while (isspace( c = GetC() ) )
-     /* Do nothing */ ;
+    if ( m_lasterror != wxSTREAM_NO_ERROR && m_lasterror != wxSTREAM_EOF )
+    {
+        // can't operate on this stream until the error is cleared
+        return 0;
+    }
 
 
-  f = 0.0;
-  if (! (c == '-' || isdigit(c)) ) {
-    InputStreamBuffer()->WriteBack(c);
-    return *this;
-  }
+    char *ptrback = AllocSpaceWBack(bufsize);
+    if (!ptrback)
+        return 0;
 
 
-  if (c == '-') {
-    sign = -1;
-    c = GetC();
-  } else
-    sign = 1;
+    // Eof() shouldn't return true any longer
+    if ( m_lasterror == wxSTREAM_EOF )
+        m_lasterror = wxSTREAM_NO_ERROR;
 
 
-  while (isdigit(c)) {
-    f = f*10 + c;
-    c = GetC();
-  }
+    memcpy(ptrback, buf, bufsize);
+    return bufsize;
+}
 
 
-  if (c == '.') {
-    float f_multiplicator = 0.1;
-    c = GetC();
+bool wxInputStream::Ungetch(char c)
+{
+    return Ungetch(&c, sizeof(c)) != 0;
+}
 
 
-    while (isdigit(c)) {
-      f += c*f_multiplicator;
-      f_multiplicator /= 10;
-      c = GetC();
-    }
-  }
+int wxInputStream::GetC()
+{
+    unsigned char c;
+    Read(&c, sizeof(c));
+    return LastRead() ? c : wxEOF;
+}
 
 
-  f *= sign;
+wxInputStream& wxInputStream::Read(void *buf, size_t size)
+{
+    wxASSERT_MSG( buf, wxT("Warning: Null pointer is about to be read") );
+
+    char *p = (char *)buf;
+    m_lastcount = 0;
+
+    size_t read = GetWBack(buf, size);
+    for ( ;; )
+    {
+        size -= read;
+        m_lastcount += read;
+        p += read;
+
+        if ( !size )
+        {
+            // we read the requested amount of data
+            break;
+        }
+
+        if ( p != buf && !CanRead() )
+        {
+            // we have already read something and we would block in OnSysRead()
+            // now: don't do it but return immediately
+            break;
+        }
+
+        read = OnSysRead(p, size);
+        if ( !read )
+        {
+            // no more data available
+            break;
+        }
+    }
 
 
-  return *this;
+    return *this;
 }
 
 }
 
-wxInputStream& wxInputStream::operator>>(wxObject *& obj)
+char wxInputStream::Peek()
 {
 {
-  wxObjectInputStream obj_s(*this);
-  obj = obj_s.LoadObject();
-  return *this;
+    char c;
+    Read(&c, sizeof(c));
+    if (m_lasterror == wxSTREAM_NO_ERROR)
+    {
+        Ungetch(c);
+        return c;
+    }
+
+    return 0;
 }
 
 }
 
-off_t wxInputStream::SeekI(off_t pos, wxSeekMode mode)
+wxInputStream& wxInputStream::Read(wxOutputStream& stream_out)
 {
 {
-  off_t ret_off, diff, last_access;
+    size_t lastcount = 0;
+    char buf[BUF_TEMP_SIZE];
+
+    for ( ;; )
+    {
+        size_t bytes_read = Read(buf, WXSIZEOF(buf)).LastRead();
+        if ( !bytes_read )
+            break;
+
+        if ( stream_out.Write(buf, bytes_read).LastWrite() != bytes_read )
+            break;
+
+        lastcount += bytes_read;
+    }
 
 
-  last_access = m_i_streambuf->GetLastAccess();
+    m_lastcount = lastcount;
 
 
-  switch (mode) {
-  case wxFromStart:
-    diff = DoTellInput() - pos;
-    if ( diff < 0 || diff > last_access  ) {
-      ret_off = DoSeekInput(pos, wxFromStart);
-      m_i_streambuf->ResetBuffer();
-      return ret_off;
-    } else {
-      m_i_streambuf->SetIntPosition(last_access - diff);
-      return pos;
+    return *this;
+}
+
+wxFileOffset wxInputStream::SeekI(wxFileOffset pos, wxSeekMode mode)
+{
+    // RR: This code is duplicated in wxBufferedInputStream. This is
+    // not really a good design, but buffered stream are different
+    // from all others in that they handle two stream-related objects:
+    // the stream buffer and parent stream.
+
+    // I don't know whether it should be put as well in wxFileInputStream::OnSysSeek
+    if (m_lasterror==wxSTREAM_EOF)
+        m_lasterror=wxSTREAM_NO_ERROR;
+
+    // avoid unnecessary seek operations (optimization)
+    wxFileOffset currentPos = TellI(), size = GetLength();
+    if ((mode == wxFromStart && currentPos == pos) ||
+        (mode == wxFromCurrent && pos == 0) ||
+        (mode == wxFromEnd && size != wxInvalidOffset && currentPos == size-pos))
+        return currentPos;
+
+    if (!IsSeekable() && mode == wxFromCurrent && pos > 0)
+    {
+        // rather than seeking, we can just read data and discard it;
+        // this allows to forward-seek also non-seekable streams!
+        char buf[BUF_TEMP_SIZE];
+        size_t bytes_read;
+
+        // read chunks of BUF_TEMP_SIZE bytes until we reach the new position
+        for ( ; pos >= BUF_TEMP_SIZE; pos -= bytes_read)
+        {
+            bytes_read = Read(buf, WXSIZEOF(buf)).LastRead();
+            if ( m_lasterror != wxSTREAM_NO_ERROR )
+                return wxInvalidOffset;
+
+            wxASSERT(bytes_read == WXSIZEOF(buf));
+        }
+
+        // read the last 'pos' bytes
+        bytes_read = Read(buf, (size_t)pos).LastRead();
+        if ( m_lasterror != wxSTREAM_NO_ERROR )
+            return wxInvalidOffset;
+
+        wxASSERT(bytes_read == (size_t)pos);
+
+        // we should now have sought to the right position...
+        return TellI();
     }
     }
-  case wxFromCurrent:
-    diff = pos + m_i_streambuf->GetIntPosition();
 
 
-    if ( (diff > last_access) || (diff < 0) ) {
-      ret_off = DoSeekInput(pos, wxFromCurrent);
-      m_i_streambuf->ResetBuffer();
-      return ret_off;
-    } else {
-      m_i_streambuf->SetIntPosition(diff);
-      return pos;
+    /* RR: A call to SeekI() will automatically invalidate any previous
+       call to Ungetch(), otherwise it would be possible to SeekI() to
+       one position, unread some bytes there, SeekI() to another position
+       and the data would be corrupted.
+
+       GRG: Could add code here to try to navigate within the wback
+       buffer if possible, but is it really needed? It would only work
+       when seeking in wxFromCurrent mode, else it would invalidate
+       anyway... */
+
+    if (m_wback)
+    {
+        wxLogDebug( wxT("Seeking in stream which has data written back to it.") );
+
+        free(m_wback);
+        m_wback = NULL;
+        m_wbacksize = 0;
+        m_wbackcur = 0;
     }
     }
-  case wxFromEnd:
-    // Hard to compute: always seek to the requested position.
-    ret_off = DoSeekInput(pos, wxFromEnd);
-    m_i_streambuf->ResetBuffer();
-    return ret_off;
-  }
-  return wxInvalidOffset;
+
+    return OnSysSeek(pos, mode);
 }
 
 }
 
-off_t wxInputStream::TellI() const
+wxFileOffset wxInputStream::TellI() const
 {
 {
-  return DoTellInput() - m_i_streambuf->GetLastAccess() +
-                         m_i_streambuf->GetIntPosition();
+    wxFileOffset pos = OnSysTell();
+
+    if (pos != wxInvalidOffset)
+        pos -= (m_wbacksize - m_wbackcur);
+
+    return pos;
 }
 
 }
 
+
 // ----------------------------------------------------------------------------
 // wxOutputStream
 // ----------------------------------------------------------------------------
 // ----------------------------------------------------------------------------
 // wxOutputStream
 // ----------------------------------------------------------------------------
+
+IMPLEMENT_ABSTRACT_CLASS(wxOutputStream, wxStreamBase)
+
 wxOutputStream::wxOutputStream()
 {
 wxOutputStream::wxOutputStream()
 {
-  m_o_destroybuf = TRUE;
-  m_o_streambuf = new wxStreamBuffer(*this);
 }
 
 }
 
-wxOutputStream::wxOutputStream(wxStreamBuffer *buffer)
+wxOutputStream::~wxOutputStream()
 {
 {
-  m_o_destroybuf = FALSE;
-  m_o_streambuf = buffer;
 }
 
 }
 
-wxOutputStream::~wxOutputStream()
+size_t wxOutputStream::OnSysWrite(const void * WXUNUSED(buffer),
+                                  size_t WXUNUSED(bufsize))
 {
 {
-  if (m_o_destroybuf)
-    delete m_o_streambuf;
+    return 0;
+}
+
+void wxOutputStream::PutC(char c)
+{
+    Write(&c, sizeof(c));
 }
 
 wxOutputStream& wxOutputStream::Write(const void *buffer, size_t size)
 {
 }
 
 wxOutputStream& wxOutputStream::Write(const void *buffer, size_t size)
 {
-  m_o_streambuf->Write(buffer, size);
-  return *this;
+    m_lastcount = OnSysWrite(buffer, size);
+    return *this;
 }
 
 wxOutputStream& wxOutputStream::Write(wxInputStream& stream_in)
 {
 }
 
 wxOutputStream& wxOutputStream::Write(wxInputStream& stream_in)
 {
-  stream_in.Read(*this);
-  return *this;
+    stream_in.Read(*this);
+    return *this;
 }
 
 }
 
-off_t wxOutputStream::SeekO(off_t pos, wxSeekMode mode)
+wxFileOffset wxOutputStream::TellO() const
 {
 {
-  off_t ret_off;
-
-  switch (mode) {
-  case wxFromStart:
-    if ( (unsigned)abs (DoTellOutput()-pos) > m_o_streambuf->GetLastAccess()  ) {
-      ret_off = DoSeekOutput(pos, wxFromStart);
-      m_o_streambuf->ResetBuffer();
-      return ret_off;
-    } else {
-      m_o_streambuf->SetIntPosition( DoTellOutput() - pos);
-      return pos;
-    }
-  case wxFromCurrent:
-    if ( ((unsigned)pos > m_o_streambuf->GetLastAccess()) || (pos < 0) ) {
-      ret_off = DoSeekOutput(pos, wxFromCurrent);
-      m_o_streambuf->ResetBuffer();
-      return ret_off;
-    } else {
-      m_o_streambuf->SetIntPosition(pos);
-      return pos;
-    }
-  case wxFromEnd:
-    // Hard to compute: always seek to the requested position.
-    ret_off = DoSeekOutput(pos, wxFromEnd);
-    m_o_streambuf->ResetBuffer();
-    return ret_off;
-  }
-  return wxInvalidOffset;
+    return OnSysTell();
 }
 
 }
 
-off_t wxOutputStream::TellO() const
+wxFileOffset wxOutputStream::SeekO(wxFileOffset pos, wxSeekMode mode)
 {
 {
-  return DoTellOutput() - m_o_streambuf->GetLastAccess()
-                        + m_o_streambuf->GetIntPosition();
+    return OnSysSeek(pos, mode);
 }
 
 void wxOutputStream::Sync()
 {
 }
 
 void wxOutputStream::Sync()
 {
-  DoWrite(m_o_streambuf->GetBufferStart(), m_o_streambuf->GetIntPosition());
+}
 
 
-  m_o_streambuf->ResetBuffer();
+
+// ----------------------------------------------------------------------------
+// wxCountingOutputStream
+// ----------------------------------------------------------------------------
+
+IMPLEMENT_DYNAMIC_CLASS(wxCountingOutputStream, wxOutputStream)
+
+wxCountingOutputStream::wxCountingOutputStream ()
+{
+     m_currentPos = 0;
 }
 
 }
 
-wxOutputStream& wxOutputStream::operator<<(const char *string)
+wxFileOffset wxCountingOutputStream::GetLength() const
 {
 {
-  return Write(string, strlen(string));
+    return m_lastcount;
 }
 
 }
 
-wxOutputStream& wxOutputStream::operator<<(wxString& string)
+size_t wxCountingOutputStream::OnSysWrite(const void *WXUNUSED(buffer),
+                                          size_t size)
 {
 {
-  return Write(string, string.Len());
+    m_currentPos += size;
+    if (m_currentPos > m_lastcount)
+        m_lastcount = m_currentPos;
+
+    return m_currentPos;
 }
 
 }
 
-wxOutputStream& wxOutputStream::operator<<(char c)
+wxFileOffset wxCountingOutputStream::OnSysSeek(wxFileOffset pos, wxSeekMode mode)
 {
 {
-  return Write(&c, 1);
+    ssize_t new_pos = wx_truncate_cast(ssize_t, pos);
+
+    switch ( mode )
+    {
+        case wxFromStart:
+            wxCHECK_MSG( (wxFileOffset)new_pos == pos, wxInvalidOffset, wxT("huge position not supported") );
+            break;
+
+        case wxFromEnd:
+            new_pos = m_lastcount + new_pos;
+            wxCHECK_MSG( (wxFileOffset)new_pos == (wxFileOffset)(m_lastcount + pos), wxInvalidOffset, wxT("huge position not supported") );
+            break;
+
+        case wxFromCurrent:
+            new_pos = m_currentPos + new_pos;
+            wxCHECK_MSG( (wxFileOffset)new_pos == (wxFileOffset)(m_currentPos + pos), wxInvalidOffset, wxT("huge position not supported") );
+            break;
+
+        default:
+            wxFAIL_MSG( wxT("invalid seek mode") );
+            return wxInvalidOffset;
+    }
+
+    m_currentPos = new_pos;
+
+    if (m_currentPos > m_lastcount)
+        m_lastcount = m_currentPos;
+
+    return m_currentPos;
 }
 
 }
 
-wxOutputStream& wxOutputStream::operator<<(short i)
+wxFileOffset wxCountingOutputStream::OnSysTell() const
 {
 {
-  wxString strint;
+    return m_currentPos;
+}
 
 
-  strint.Printf("%i", i);
-  return Write(strint, strint.Len());
+// ----------------------------------------------------------------------------
+// wxFilterInputStream
+// ----------------------------------------------------------------------------
+
+IMPLEMENT_ABSTRACT_CLASS(wxFilterInputStream, wxInputStream)
+
+wxFilterInputStream::wxFilterInputStream()
+ :  m_parent_i_stream(NULL),
+    m_owns(false)
+{
 }
 
 }
 
-wxOutputStream& wxOutputStream::operator<<(int i)
+wxFilterInputStream::wxFilterInputStream(wxInputStream& stream)
+ :  m_parent_i_stream(&stream),
+    m_owns(false)
+{
+}
+
+wxFilterInputStream::wxFilterInputStream(wxInputStream *stream)
+ :  m_parent_i_stream(stream),
+    m_owns(true)
 {
 {
-  wxString strint;
+}
 
 
-  strint.Printf("%i", i);
-  return Write(strint, strint.Len());
+wxFilterInputStream::~wxFilterInputStream()
+{
+    if (m_owns)
+        delete m_parent_i_stream;
 }
 
 }
 
-wxOutputStream& wxOutputStream::operator<<(long i)
+// ----------------------------------------------------------------------------
+// wxFilterOutputStream
+// ----------------------------------------------------------------------------
+
+IMPLEMENT_ABSTRACT_CLASS(wxFilterOutputStream, wxOutputStream)
+
+wxFilterOutputStream::wxFilterOutputStream()
+ :  m_parent_o_stream(NULL),
+    m_owns(false)
 {
 {
-  wxString strlong;
+}
 
 
-  strlong.Printf("%i", i);
-  return Write((const char *)strlong, strlong.Len());
+wxFilterOutputStream::wxFilterOutputStream(wxOutputStream& stream)
+ :  m_parent_o_stream(&stream),
+    m_owns(false)
+{
 }
 
 }
 
-wxOutputStream& wxOutputStream::operator<<(double f)
+wxFilterOutputStream::wxFilterOutputStream(wxOutputStream *stream)
+ :  m_parent_o_stream(stream),
+    m_owns(true)
 {
 {
-  wxString strfloat;
+}
 
 
-  strfloat.Printf("%f", f);
-  return Write(strfloat, strfloat.Len());
+bool wxFilterOutputStream::Close()
+{
+    if (m_parent_o_stream && m_owns)
+        return m_parent_o_stream->Close();
+    else
+        return true;
 }
 
 }
 
-wxOutputStream& wxOutputStream::operator<<(wxObject& obj)
+wxFilterOutputStream::~wxFilterOutputStream()
 {
 {
-  wxObjectOutputStream obj_s(*this);
-  obj_s.SaveObject(obj);
-  return *this;
+    if (m_owns)
+        delete m_parent_o_stream;
 }
 
 // ----------------------------------------------------------------------------
 }
 
 // ----------------------------------------------------------------------------
-// wxFilterInputStream
+// wxFilterClassFactoryBase
 // ----------------------------------------------------------------------------
 // ----------------------------------------------------------------------------
-wxFilterInputStream::wxFilterInputStream(wxInputStream& stream)
-  : wxInputStream(NULL)
+
+IMPLEMENT_ABSTRACT_CLASS(wxFilterClassFactoryBase, wxObject)
+
+wxString wxFilterClassFactoryBase::PopExtension(const wxString& location) const
 {
 {
-  m_parent_i_stream = &stream;
-  m_i_streambuf = stream.InputStreamBuffer();
+    return location.substr(0, FindExtension(location));
 }
 
 }
 
-wxFilterInputStream::~wxFilterInputStream()
+wxString::size_type wxFilterClassFactoryBase::FindExtension(
+        const wxString& location) const
+{
+    for (const wxChar *const *p = GetProtocols(wxSTREAM_FILEEXT); *p; p++)
+    {
+        if ( location.EndsWith(*p) )
+            return location.length() - wxStrlen(*p);
+    }
+
+    return wxString::npos;
+}
+
+bool wxFilterClassFactoryBase::CanHandle(const wxString& protocol,
+                                         wxStreamProtocolType type) const
+{
+    if (type == wxSTREAM_FILEEXT)
+        return FindExtension(protocol) != wxString::npos;
+    else
+        for (const wxChar *const *p = GetProtocols(type); *p; p++)
+            if (protocol == *p)
+                return true;
+
+    return false;
+}
+
+// ----------------------------------------------------------------------------
+// wxFilterClassFactory
+// ----------------------------------------------------------------------------
+
+IMPLEMENT_ABSTRACT_CLASS(wxFilterClassFactory, wxFilterClassFactoryBase)
+
+wxFilterClassFactory *wxFilterClassFactory::sm_first = NULL;
+
+void wxFilterClassFactory::Remove()
+{
+    if (m_next != this)
+    {
+        wxFilterClassFactory **pp = &sm_first;
+
+        while (*pp != this)
+            pp = &(*pp)->m_next;
+
+        *pp = m_next;
+
+        m_next = this;
+    }
+}
+
+// ----------------------------------------------------------------------------
+// wxBufferedInputStream
+// ----------------------------------------------------------------------------
+
+namespace
+{
+
+// helper function used for initializing the buffer used by
+// wxBufferedInput/OutputStream: it simply returns the provided buffer if it's
+// not NULL or creates a buffer of the given size otherwise
+template <typename T>
+wxStreamBuffer *
+CreateBufferIfNeeded(T& stream, wxStreamBuffer *buffer, size_t bufsize = 1024)
+{
+    return buffer ? buffer : new wxStreamBuffer(bufsize, stream);
+}
+
+} // anonymous namespace
+
+wxBufferedInputStream::wxBufferedInputStream(wxInputStream& stream,
+                                             wxStreamBuffer *buffer)
+                     : wxFilterInputStream(stream)
+{
+    m_i_streambuf = CreateBufferIfNeeded(*this, buffer);
+}
+
+wxBufferedInputStream::wxBufferedInputStream(wxInputStream& stream,
+                                             size_t bufsize)
+                     : wxFilterInputStream(stream)
+{
+    m_i_streambuf = CreateBufferIfNeeded(*this, NULL, bufsize);
+}
+
+wxBufferedInputStream::~wxBufferedInputStream()
+{
+    m_parent_i_stream->SeekI(-(wxFileOffset)m_i_streambuf->GetBytesLeft(),
+                             wxFromCurrent);
+
+    delete m_i_streambuf;
+}
+
+char wxBufferedInputStream::Peek()
+{
+    return m_i_streambuf->Peek();
+}
+
+wxInputStream& wxBufferedInputStream::Read(void *buf, size_t size)
+{
+    // reset the error flag
+    Reset();
+
+    // first read from the already cached data
+    m_lastcount = GetWBack(buf, size);
+
+    // do we have to read anything more?
+    if ( m_lastcount < size )
+    {
+        size -= m_lastcount;
+        buf = (char *)buf + m_lastcount;
+
+        // the call to wxStreamBuffer::Read() below may reset our m_lastcount
+        // (but it also may not do it if the buffer is associated to another
+        // existing stream and wasn't created by us), so save it
+        size_t countOld = m_lastcount;
+
+        // the new count of the bytes read is the count of bytes read this time
+        m_lastcount = m_i_streambuf->Read(buf, size);
+
+        // plus those we had read before
+        m_lastcount += countOld;
+    }
+
+    return *this;
+}
+
+wxFileOffset wxBufferedInputStream::SeekI(wxFileOffset pos, wxSeekMode mode)
 {
 {
+    // RR: Look at wxInputStream for comments.
+
+    if (m_lasterror==wxSTREAM_EOF)
+        Reset();
+
+    if (m_wback)
+    {
+        wxLogDebug( wxT("Seeking in stream which has data written back to it.") );
+
+        free(m_wback);
+        m_wback = NULL;
+        m_wbacksize = 0;
+        m_wbackcur = 0;
+    }
+
+    return m_i_streambuf->Seek(pos, mode);
 }
 
 }
 
-size_t wxFilterInputStream::DoRead(void *buffer, size_t size)
+wxFileOffset wxBufferedInputStream::TellI() const
 {
 {
-  return m_parent_i_stream->Read(buffer, size).LastRead();
+    wxFileOffset pos = m_i_streambuf->Tell();
+
+    if (pos != wxInvalidOffset)
+        pos -= (m_wbacksize - m_wbackcur);
+
+    return pos;
 }
 
 }
 
-off_t wxFilterInputStream::DoSeekInput(off_t pos, wxSeekMode mode)
+size_t wxBufferedInputStream::OnSysRead(void *buffer, size_t bufsize)
 {
 {
-  return m_parent_i_stream->SeekI(pos, mode);
+    return m_parent_i_stream->Read(buffer, bufsize).LastRead();
 }
 
 }
 
-off_t wxFilterInputStream::DoTellInput() const
+wxFileOffset wxBufferedInputStream::OnSysSeek(wxFileOffset seek, wxSeekMode mode)
 {
 {
-  return m_parent_i_stream->TellI();
+    return m_parent_i_stream->SeekI(seek, mode);
 }
 
 }
 
+wxFileOffset wxBufferedInputStream::OnSysTell() const
+{
+    return m_parent_i_stream->TellI();
+}
+
+void wxBufferedInputStream::SetInputStreamBuffer(wxStreamBuffer *buffer)
+{
+    wxCHECK_RET( buffer, wxT("wxBufferedInputStream needs buffer") );
+
+    delete m_i_streambuf;
+    m_i_streambuf = buffer;
+}
 
 // ----------------------------------------------------------------------------
 
 // ----------------------------------------------------------------------------
-// wxFilterOutputStream
+// wxBufferedOutputStream
 // ----------------------------------------------------------------------------
 // ----------------------------------------------------------------------------
-wxFilterOutputStream::wxFilterOutputStream(wxOutputStream& stream)
-  : wxOutputStream(NULL)
+
+wxBufferedOutputStream::wxBufferedOutputStream(wxOutputStream& stream,
+                                               wxStreamBuffer *buffer)
+                      : wxFilterOutputStream(stream)
 {
 {
-  m_parent_o_stream = &stream;
-  m_o_streambuf = stream.OutputStreamBuffer();
+    m_o_streambuf = CreateBufferIfNeeded(*this, buffer);
 }
 
 }
 
-wxFilterOutputStream::~wxFilterOutputStream()
+wxBufferedOutputStream::wxBufferedOutputStream(wxOutputStream& stream,
+                                               size_t bufsize)
+                      : wxFilterOutputStream(stream)
 {
 {
+    m_o_streambuf = CreateBufferIfNeeded(*this, NULL, bufsize);
 }
 
 }
 
-size_t wxFilterOutputStream::DoWrite(const void *buffer, size_t size)
+wxBufferedOutputStream::~wxBufferedOutputStream()
 {
 {
-  return m_parent_o_stream->Write(buffer, size).LastWrite();
+    Sync();
+    delete m_o_streambuf;
 }
 
 }
 
-off_t wxFilterOutputStream::DoSeekOutput(off_t pos, wxSeekMode mode)
+bool wxBufferedOutputStream::Close()
 {
 {
-  return m_parent_o_stream->SeekO(pos, mode);
+    Sync();
+    return IsOk();
 }
 
 }
 
-off_t wxFilterOutputStream::DoTellOutput() const
+
+wxOutputStream& wxBufferedOutputStream::Write(const void *buffer, size_t size)
 {
 {
-  return m_parent_o_stream->TellO();
+    m_lastcount = 0;
+    m_o_streambuf->Write(buffer, size);
+    return *this;
+}
+
+wxFileOffset wxBufferedOutputStream::SeekO(wxFileOffset pos, wxSeekMode mode)
+{
+    Sync();
+    return m_o_streambuf->Seek(pos, mode);
+}
+
+wxFileOffset wxBufferedOutputStream::TellO() const
+{
+    return m_o_streambuf->Tell();
+}
+
+void wxBufferedOutputStream::Sync()
+{
+    m_o_streambuf->FlushBuffer();
+    m_parent_o_stream->Sync();
+}
+
+size_t wxBufferedOutputStream::OnSysWrite(const void *buffer, size_t bufsize)
+{
+    return m_parent_o_stream->Write(buffer, bufsize).LastWrite();
+}
+
+wxFileOffset wxBufferedOutputStream::OnSysSeek(wxFileOffset seek, wxSeekMode mode)
+{
+    return m_parent_o_stream->SeekO(seek, mode);
+}
+
+wxFileOffset wxBufferedOutputStream::OnSysTell() const
+{
+    return m_parent_o_stream->TellO();
+}
+
+wxFileOffset wxBufferedOutputStream::GetLength() const
+{
+   return m_parent_o_stream->GetLength() + m_o_streambuf->GetIntPosition();
+}
+
+void wxBufferedOutputStream::SetOutputStreamBuffer(wxStreamBuffer *buffer)
+{
+    wxCHECK_RET( buffer, wxT("wxBufferedOutputStream needs buffer") );
+
+    delete m_o_streambuf;
+    m_o_streambuf = buffer;
+}
+
+// ---------------------------------------------------------------------------
+// wxWrapperInputStream implementation
+// ---------------------------------------------------------------------------
+
+wxWrapperInputStream::wxWrapperInputStream()
+{
+    m_lasterror = wxSTREAM_READ_ERROR;
+}
+
+wxWrapperInputStream::wxWrapperInputStream(wxInputStream& stream)
+    : wxFilterInputStream(stream)
+{
+    SynchronizeLastError();
+}
+
+wxWrapperInputStream::wxWrapperInputStream(wxInputStream *stream)
+    : wxFilterInputStream(stream)
+{
+    if ( m_parent_i_stream )
+        SynchronizeLastError();
+    else
+        m_lasterror = wxSTREAM_READ_ERROR;
+}
+
+void wxWrapperInputStream::InitParentStream(wxInputStream& stream)
+{
+    wxCHECK_RET( !m_parent_i_stream, "Can't init parent stream twice" );
+
+    m_parent_i_stream = &stream;
+
+    SynchronizeLastError();
+}
+
+void wxWrapperInputStream::InitParentStream(wxInputStream* stream)
+{
+    wxCHECK_RET( !m_parent_i_stream, "Can't init parent stream twice" );
+
+    m_parent_i_stream = stream;
+
+    if ( m_parent_i_stream )
+    {
+        m_owns = true;
+
+        SynchronizeLastError();
+    }
+}
+
+wxFileOffset wxWrapperInputStream::GetLength() const
+{
+    wxCHECK_MSG(m_parent_i_stream, wxInvalidOffset, "Stream not valid");
+
+    wxON_BLOCK_EXIT_THIS0(wxWrapperInputStream::SynchronizeLastError);
+    return m_parent_i_stream->GetLength();
+}
+
+bool wxWrapperInputStream::IsSeekable() const
+{
+    wxCHECK_MSG(m_parent_i_stream, false, "Stream not valid");
+    return m_parent_i_stream->IsSeekable();
+}
+
+size_t wxWrapperInputStream::OnSysRead(void *buffer, size_t size)
+{
+    wxCHECK_MSG(m_parent_i_stream, false, "Stream not valid");
+
+    wxON_BLOCK_EXIT_THIS0(wxWrapperInputStream::SynchronizeLastError);
+
+    m_parent_i_stream->Read(buffer, size);
+    return m_parent_i_stream->LastRead();
+}
+
+wxFileOffset wxWrapperInputStream::OnSysSeek(wxFileOffset pos, wxSeekMode mode)
+{
+    wxCHECK_MSG(IsSeekable(), false, "Stream not seekable");
+
+    wxON_BLOCK_EXIT_THIS0(wxWrapperInputStream::SynchronizeLastError);
+    return m_parent_i_stream->SeekI (pos, mode);
+}
+
+wxFileOffset wxWrapperInputStream::OnSysTell() const
+{
+    wxCHECK_MSG(m_parent_i_stream, false, "Stream not valid");
+
+    wxON_BLOCK_EXIT_THIS0(wxWrapperInputStream::SynchronizeLastError);
+    return m_parent_i_stream->TellI();
 }
 
 // ----------------------------------------------------------------------------
 }
 
 // ----------------------------------------------------------------------------
@@ -606,9 +1540,9 @@ off_t wxFilterOutputStream::DoTellOutput() const
 
 wxOutputStream& wxEndL(wxOutputStream& stream)
 {
 
 wxOutputStream& wxEndL(wxOutputStream& stream)
 {
-#ifdef __MSW__
-  return stream.Write("\r\n", 2);
-#else
-  return stream.Write("\n", 1);
-#endif
+    static const wxChar *eol = wxTextFile::GetEOL();
+
+    return stream.Write(eol, wxStrlen(eol));
 }
 }
+
+#endif // wxUSE_STREAMS
wxWidgets (Impactor)