remove unnecessary include of wx/cairo.h

[wxWidgets.git] / src / common / stream.cpp

diff --git a/src/common/stream.cpp b/src/common/stream.cpp
index c612f4835b6b5fa3f3b1e34745802a295aaf5575..f7cd2ea2c58db63aa52248adc2857100f501c1e5 100644 (file)
--- a/src/common/stream.cpp
+++ b/src/common/stream.cpp
@@ -36,6 +36,7 @@
 #include <ctype.h>
 #include "wx/datstrm.h"
 #include "wx/textfile.h"
 #include <ctype.h>
 #include "wx/datstrm.h"
 #include "wx/textfile.h"

+#include "wx/scopeguard.h"

 
 // ----------------------------------------------------------------------------
 // constants
 
 // ----------------------------------------------------------------------------
 // constants


@@ -75,24 +76,24 @@ void wxStreamBuffer::Init()
     m_fixed = true;
 }
 
     m_fixed = true;
 }
 

-wxStreamBuffer::wxStreamBuffer(BufMode mode)
+void wxStreamBuffer::InitWithStream(wxStreamBase& stream, BufMode mode)

 {
     Init();
 
 {
     Init();
 

-    m_stream = NULL;
+    m_stream = &stream;

     m_mode = mode;
 
     m_mode = mode;
 

-    m_flushable = false;
+    m_flushable = true;

 }
 
 }
 

-wxStreamBuffer::wxStreamBuffer(wxStreamBase& stream, BufMode mode)
+wxStreamBuffer::wxStreamBuffer(BufMode mode)

 {
     Init();
 
 {
     Init();
 

-    m_stream = &stream;
+    m_stream = NULL;

     m_mode = mode;
 
     m_mode = mode;
 

-    m_flushable = true;
+    m_flushable = false;

 }
 
 wxStreamBuffer::wxStreamBuffer(const wxStreamBuffer& buffer)
 }
 
 wxStreamBuffer::wxStreamBuffer(const wxStreamBuffer& buffer)


@@ -100,7 +101,7 @@ 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,
     // 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,

-                  _T("it's a bad idea to copy this buffer") );
+                  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_start = buffer.m_buffer_start;
     m_buffer_end = buffer.m_buffer_end;


@@ -202,7 +203,7 @@ void wxStreamBuffer::Truncate()
     }
 
     char *new_start = (char *)realloc(m_buffer_start, new_size);
     }
 
     char *new_start = (char *)realloc(m_buffer_start, new_size);

-    wxCHECK_RET( new_size, _T("shrinking buffer shouldn't fail") );
+    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_start = new_start;
     m_buffer_end = m_buffer_start + new_size;


@@ -231,7 +232,7 @@ bool wxStreamBuffer::FillBuffer()
 // write the buffer contents to the stream (only for write buffers)
 bool wxStreamBuffer::FlushBuffer()
 {
 // write the buffer contents to the stream (only for write buffers)
 bool wxStreamBuffer::FlushBuffer()
 {

-    wxCHECK_MSG( m_flushable, false, _T("can't flush this buffer") );
+    wxCHECK_MSG( m_flushable, false, wxT("can't flush this buffer") );

 
     // FIXME: what is this check for? (VZ)
     if ( m_buffer_pos == m_buffer_start )
 
     // FIXME: what is this check for? (VZ)
     if ( m_buffer_pos == m_buffer_start )


@@ -239,7 +240,7 @@ bool wxStreamBuffer::FlushBuffer()
 
     wxOutputStream *outStream = GetOutputStream();
 
 
     wxOutputStream *outStream = GetOutputStream();
 

-    wxCHECK_MSG( outStream, false, _T("should have a stream in wxStreamBuffer") );
+    wxCHECK_MSG( outStream, false, wxT("should have a stream in wxStreamBuffer") );

 
     size_t current = m_buffer_pos - m_buffer_start;
     size_t count = outStream->OnSysWrite(m_buffer_start, current);
 
     size_t current = m_buffer_pos - m_buffer_start;
     size_t count = outStream->OnSysWrite(m_buffer_start, current);


@@ -319,7 +320,7 @@ void wxStreamBuffer::PutChar(char c)
 {
     wxOutputStream *outStream = GetOutputStream();
 
 {
     wxOutputStream *outStream = GetOutputStream();
 

-    wxCHECK_RET( outStream, _T("should have a stream in wxStreamBuffer") );
+    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() )
 
     // if we don't have buffer at all, just forward this call to the stream,
     if ( !HasBuffer() )


@@ -345,7 +346,7 @@ void wxStreamBuffer::PutChar(char c)
 char wxStreamBuffer::Peek()
 {
     wxCHECK_MSG( m_stream && HasBuffer(), 0,
 char wxStreamBuffer::Peek()
 {
     wxCHECK_MSG( m_stream && HasBuffer(), 0,

-                 _T("should have the stream and the buffer in wxStreamBuffer") );
+                 wxT("should have the stream and the buffer in wxStreamBuffer") );

 
     if ( !GetDataLeft() )
     {
 
     if ( !GetDataLeft() )
     {


@@ -364,7 +365,7 @@ char wxStreamBuffer::GetChar()
 {
     wxInputStream *inStream = GetInputStream();
 
 {
     wxInputStream *inStream = GetInputStream();
 

-    wxCHECK_MSG( inStream, 0, _T("should have a stream in wxStreamBuffer") );
+    wxCHECK_MSG( inStream, 0, wxT("should have a stream in wxStreamBuffer") );

 
     char c;
     if ( !HasBuffer() )
 
     char c;
     if ( !HasBuffer() )


@@ -390,7 +391,7 @@ char wxStreamBuffer::GetChar()
 
 size_t wxStreamBuffer::Read(void *buffer, size_t size)
 {
 
 size_t wxStreamBuffer::Read(void *buffer, size_t size)
 {

-    wxASSERT_MSG( buffer, _T("Warning: Null pointer is about to be used") );
+    wxASSERT_MSG( buffer, wxT("Warning: Null pointer is about to be used") );

 
     /* Clear buffer first */
     memset(buffer, 0x00, size);
 
     /* Clear buffer first */
     memset(buffer, 0x00, size);


@@ -404,7 +405,7 @@ size_t wxStreamBuffer::Read(void *buffer, size_t size)
     {
         wxInputStream *inStream = GetInputStream();
 
     {
         wxInputStream *inStream = GetInputStream();
 

-        wxCHECK_MSG( inStream, 0, _T("should have a stream in wxStreamBuffer") );
+        wxCHECK_MSG( inStream, 0, wxT("should have a stream in wxStreamBuffer") );

 
         readBytes = inStream->OnSysRead(buffer, size);
     }
 
         readBytes = inStream->OnSysRead(buffer, size);
     }


@@ -449,7 +450,7 @@ size_t wxStreamBuffer::Read(void *buffer, size_t size)
 // this should really be called "Copy()"
 size_t wxStreamBuffer::Read(wxStreamBuffer *dbuf)
 {
 // this should really be called "Copy()"
 size_t wxStreamBuffer::Read(wxStreamBuffer *dbuf)
 {

-    wxCHECK_MSG( m_mode != write, 0, _T("can't read from this buffer") );
+    wxCHECK_MSG( m_mode != write, 0, wxT("can't read from this buffer") );

 
     char buf[BUF_TEMP_SIZE];
     size_t nRead,
 
     char buf[BUF_TEMP_SIZE];
     size_t nRead,


@@ -471,7 +472,7 @@ size_t wxStreamBuffer::Read(wxStreamBuffer *dbuf)
 
 size_t wxStreamBuffer::Write(const void *buffer, size_t size)
 {
 
 size_t wxStreamBuffer::Write(const void *buffer, size_t size)
 {

-    wxASSERT_MSG( buffer, _T("Warning: Null pointer is about to be send") );
+    wxASSERT_MSG( buffer, wxT("Warning: Null pointer is about to be send") );

 
     if (m_stream)
     {
 
     if (m_stream)
     {


@@ -485,7 +486,7 @@ size_t wxStreamBuffer::Write(const void *buffer, size_t size)
     {
         wxOutputStream *outStream = GetOutputStream();
 
     {
         wxOutputStream *outStream = GetOutputStream();
 

-        wxCHECK_MSG( outStream, 0, _T("should have a stream in wxStreamBuffer") );
+        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);
 
         // no buffer, just forward the call to the stream
         ret = outStream->OnSysWrite(buffer, size);


@@ -543,8 +544,8 @@ size_t wxStreamBuffer::Write(const void *buffer, size_t size)
 
 size_t wxStreamBuffer::Write(wxStreamBuffer *sbuf)
 {
 
 size_t wxStreamBuffer::Write(wxStreamBuffer *sbuf)
 {

-    wxCHECK_MSG( m_mode != read, 0, _T("can't write to this buffer") );
-    wxCHECK_MSG( sbuf->m_mode != write, 0, _T("can't read from that buffer") );
+    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,
 
     char buf[BUF_TEMP_SIZE];
     size_t nWrite,


@@ -599,7 +600,7 @@ wxFileOffset wxStreamBuffer::Seek(wxFileOffset pos, wxSeekMode mode)
                 break;
 
             default:
                 break;
 
             default:

-                wxFAIL_MSG( _T("invalid seek mode") );
+                wxFAIL_MSG( wxT("invalid seek mode") );

 
                 return wxInvalidOffset;
         }
 
                 return wxInvalidOffset;
         }


@@ -635,7 +636,7 @@ wxFileOffset wxStreamBuffer::Seek(wxFileOffset pos, wxSeekMode mode)
                 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);
                 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 pos;
+                return diff;

             }
 
         case wxFromEnd:
             }
 
         case wxFromEnd:


@@ -695,7 +696,7 @@ size_t wxStreamBase::GetSize() const
         return 0;
 
     const size_t len = wx_truncate_cast(size_t, length);
         return 0;
 
     const size_t len = wx_truncate_cast(size_t, length);

-    wxASSERT_MSG( len == length + size_t(0), _T("large files not supported") );
+    wxASSERT_MSG( len == length + size_t(0), wxT("large files not supported") );

 
     return len;
 }
 
     return len;
 }


@@ -771,7 +772,7 @@ char *wxInputStream::AllocSpaceWBack(size_t needed_size)
 
 size_t wxInputStream::GetWBack(void *buf, size_t size)
 {
 
 size_t wxInputStream::GetWBack(void *buf, size_t size)
 {

-    wxASSERT_MSG( buf, _T("Warning: Null pointer is about to be used") );
+    wxASSERT_MSG( buf, wxT("Warning: Null pointer is about to be used") );

 
     /* Clear buffer first */
     memset(buf, 0x00, size);
 
     /* Clear buffer first */
     memset(buf, 0x00, size);


@@ -807,7 +808,7 @@ size_t wxInputStream::GetWBack(void *buf, size_t size)
 
 size_t wxInputStream::Ungetch(const void *buf, size_t bufsize)
 {
 
 size_t wxInputStream::Ungetch(const void *buf, size_t bufsize)
 {

-    wxASSERT_MSG( buf, _T("Warning: Null pointer is about to be used in Ungetch()") );
+    wxASSERT_MSG( buf, wxT("Warning: Null pointer is about to be used in Ungetch()") );

 
     if ( m_lasterror != wxSTREAM_NO_ERROR && m_lasterror != wxSTREAM_EOF )
     {
 
     if ( m_lasterror != wxSTREAM_NO_ERROR && m_lasterror != wxSTREAM_EOF )
     {


@@ -841,7 +842,7 @@ int wxInputStream::GetC()
 
 wxInputStream& wxInputStream::Read(void *buf, size_t size)
 {
 
 wxInputStream& wxInputStream::Read(void *buf, size_t size)
 {

-    wxASSERT_MSG( buf, _T("Warning: Null pointer is about to be read") );
+    wxASSERT_MSG( buf, wxT("Warning: Null pointer is about to be read") );

 
     char *p = (char *)buf;
     m_lastcount = 0;
 
     char *p = (char *)buf;
     m_lastcount = 0;


@@ -916,13 +917,48 @@ 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
 {
     // RR: This code is duplicated in wxBufferedInputStream. This is
     // not really a good design, but buffered stream are different

-    // from all other in that they handle two stream-related objects,
+    // 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;
 
     // 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();
+    }
+

     /* 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
     /* 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


@@ -1056,7 +1092,7 @@ wxFileOffset wxCountingOutputStream::OnSysSeek(wxFileOffset pos, wxSeekMode mode
             break;
 
         default:
             break;
 
         default:

-            wxFAIL_MSG( _T("invalid seek mode") );
+            wxFAIL_MSG( wxT("invalid seek mode") );

             return wxInvalidOffset;
     }
 
             return wxInvalidOffset;
     }
 


@@ -1204,21 +1240,33 @@ void wxFilterClassFactory::Remove()
 // wxBufferedInputStream
 // ----------------------------------------------------------------------------
 
 // wxBufferedInputStream
 // ----------------------------------------------------------------------------
 

-wxBufferedInputStream::wxBufferedInputStream(wxInputStream& s,
+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)
                                              wxStreamBuffer *buffer)

-                     : wxFilterInputStream(s)
+                     : wxFilterInputStream(stream)

 {
 {

-    if ( buffer )
-    {
-        // use the buffer provided by the user
-        m_i_streambuf = buffer;
-    }
-    else // create a default buffer
-    {
-        m_i_streambuf = new wxStreamBuffer(*this, wxStreamBuffer::read);
+    m_i_streambuf = CreateBufferIfNeeded(*this, buffer);
+}

 
 

-        m_i_streambuf->SetBufferIO(1024);
-    }
+wxBufferedInputStream::wxBufferedInputStream(wxInputStream& stream,
+                                             size_t bufsize)
+                     : wxFilterInputStream(stream)
+{
+    m_i_streambuf = CreateBufferIfNeeded(*this, NULL, bufsize);

 }
 
 wxBufferedInputStream::~wxBufferedInputStream()
 }
 
 wxBufferedInputStream::~wxBufferedInputStream()


@@ -1248,12 +1296,15 @@ wxInputStream& wxBufferedInputStream::Read(void *buf, size_t size)
         size -= m_lastcount;
         buf = (char *)buf + m_lastcount;
 
         size -= m_lastcount;
         buf = (char *)buf + m_lastcount;
 

-        // the call to wxStreamBuffer::Read() below will reset our m_lastcount,
-        // so save it
+        // 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;
 
         size_t countOld = m_lastcount;
 

-        m_i_streambuf->Read(buf, size);
+        // 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;
     }
 
         m_lastcount += countOld;
     }
 


@@ -1307,7 +1358,7 @@ wxFileOffset wxBufferedInputStream::OnSysTell() const
 
 void wxBufferedInputStream::SetInputStreamBuffer(wxStreamBuffer *buffer)
 {
 
 void wxBufferedInputStream::SetInputStreamBuffer(wxStreamBuffer *buffer)
 {

-    wxCHECK_RET( buffer, _T("wxBufferedInputStream needs buffer") );
+    wxCHECK_RET( buffer, wxT("wxBufferedInputStream needs buffer") );

 
     delete m_i_streambuf;
     m_i_streambuf = buffer;
 
     delete m_i_streambuf;
     m_i_streambuf = buffer;


@@ -1317,20 +1368,18 @@ void wxBufferedInputStream::SetInputStreamBuffer(wxStreamBuffer *buffer)
 // wxBufferedOutputStream
 // ----------------------------------------------------------------------------
 
 // wxBufferedOutputStream
 // ----------------------------------------------------------------------------
 

-wxBufferedOutputStream::wxBufferedOutputStream(wxOutputStream& s,
+wxBufferedOutputStream::wxBufferedOutputStream(wxOutputStream& stream,

                                                wxStreamBuffer *buffer)
                                                wxStreamBuffer *buffer)

-                      : wxFilterOutputStream(s)
+                      : wxFilterOutputStream(stream)

 {
 {

-    if ( buffer )
-    {
-        m_o_streambuf = buffer;
-    }
-    else // create a default one
-    {
-        m_o_streambuf = new wxStreamBuffer(*this, wxStreamBuffer::write);
+    m_o_streambuf = CreateBufferIfNeeded(*this, buffer);
+}

 
 

-        m_o_streambuf->SetBufferIO(1024);
-    }
+wxBufferedOutputStream::wxBufferedOutputStream(wxOutputStream& stream,
+                                               size_t bufsize)
+                      : wxFilterOutputStream(stream)
+{
+    m_o_streambuf = CreateBufferIfNeeded(*this, NULL, bufsize);

 }
 
 wxBufferedOutputStream::~wxBufferedOutputStream()
 }
 
 wxBufferedOutputStream::~wxBufferedOutputStream()


@@ -1392,12 +1441,99 @@ wxFileOffset wxBufferedOutputStream::GetLength() const
 
 void wxBufferedOutputStream::SetOutputStreamBuffer(wxStreamBuffer *buffer)
 {
 
 void wxBufferedOutputStream::SetOutputStreamBuffer(wxStreamBuffer *buffer)
 {

-    wxCHECK_RET( buffer, _T("wxBufferedOutputStream needs buffer") );
+    wxCHECK_RET( buffer, wxT("wxBufferedOutputStream needs buffer") );

 
     delete m_o_streambuf;
     m_o_streambuf = 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();
+}
+

 // ----------------------------------------------------------------------------
 // Some IOManip function
 // ----------------------------------------------------------------------------
 // ----------------------------------------------------------------------------
 // Some IOManip function
 // ----------------------------------------------------------------------------