fixing overrelease and out-of-bounds write, fixes #13725

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

diff --git a/src/common/mstream.cpp b/src/common/mstream.cpp
index b0819a26ce0ff91a404f349c49222b75429986d2..66af403e2f8140fe46874da4ddd3dcf8902f4cd1 100644 (file)
--- a/src/common/mstream.cpp
+++ b/src/common/mstream.cpp
@@ -1,125 +1,207 @@
 /////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////

-// Name:        mstream.cpp
+// Name:        src/common/mstream.cpp

 // Purpose:     "Memory stream" classes
 // Author:      Guilhem Lavaux
 // Purpose:     "Memory stream" classes
 // Author:      Guilhem Lavaux

-// Modified by:
+// Modified by: VZ (23.11.00): general code review

 // Created:     04/01/98
 // RCS-ID:      $Id$
 // Copyright:   (c) Guilhem Lavaux
 // Created:     04/01/98
 // RCS-ID:      $Id$
 // Copyright:   (c) Guilhem Lavaux

-// Licence:     wxWindows license
+// Licence:     wxWindows licence

 /////////////////////////////////////////////////////////////////////////////
 
 /////////////////////////////////////////////////////////////////////////////
 

-#ifdef __GNUG__
-#pragma implementation "mstream.h"
-#endif
+// ============================================================================
+// declarations
+// ============================================================================
+
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------

 
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 #ifdef __BORLANDC__
 
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 #ifdef __BORLANDC__

-  #pragma hdrstop
+    #pragma hdrstop

 #endif
 
 #if wxUSE_STREAMS
 
 #endif
 
 #if wxUSE_STREAMS
 

-#include <stdlib.h>
-#include "wx/stream.h"

 #include "wx/mstream.h"
 
 #include "wx/mstream.h"
 

+#ifndef   WX_PRECOMP
+    #include  "wx/stream.h"
+#endif  //WX_PRECOMP
+
+#include <stdlib.h>
+
+// ============================================================================
+// implementation
+// ============================================================================
+

 // ----------------------------------------------------------------------------
 // wxMemoryInputStream
 // ----------------------------------------------------------------------------
 
 // ----------------------------------------------------------------------------
 // wxMemoryInputStream
 // ----------------------------------------------------------------------------
 

-wxMemoryInputStream::wxMemoryInputStream(const char *data, size_t len)
-  : wxInputStream()
+IMPLEMENT_ABSTRACT_CLASS(wxMemoryInputStream, wxInputStream)
+
+wxMemoryInputStream::wxMemoryInputStream(const void *data, size_t len)
+{
+    m_i_streambuf = new wxStreamBuffer(wxStreamBuffer::read);
+    m_i_streambuf->SetBufferIO(const_cast<void *>(data), len);
+    m_i_streambuf->SetIntPosition(0); // seek to start pos
+    m_i_streambuf->Fixed(true);
+
+    m_length = len;
+}
+
+wxMemoryInputStream::wxMemoryInputStream(const wxMemoryOutputStream& stream)
+{
+    const wxFileOffset lenFile = stream.GetLength();
+    if ( lenFile == wxInvalidOffset )
+    {
+        m_i_streambuf = NULL;
+        m_lasterror = wxSTREAM_EOF;
+        return;
+    }
+
+    const size_t len = wx_truncate_cast(size_t, lenFile);
+    wxASSERT_MSG( len == lenFile + size_t(0), wxT("huge files not supported") );
+
+    m_i_streambuf = new wxStreamBuffer(wxStreamBuffer::read);
+    m_i_streambuf->SetBufferIO(len); // create buffer
+    stream.CopyTo(m_i_streambuf->GetBufferStart(), len);
+    m_i_streambuf->SetIntPosition(0); // seek to start pos
+    m_i_streambuf->Fixed(true);
+    m_length = len;
+}
+
+void
+wxMemoryInputStream::InitFromStream(wxInputStream& stream, wxFileOffset lenFile)

 {
 {

-  m_i_streambuf = new wxStreamBuffer(wxStreamBuffer::read);
-  m_i_streambuf->SetBufferIO((char*) data, (char*) (data+len));
-  m_i_streambuf->SetIntPosition(0); // seek to start pos
-  m_i_streambuf->Fixed(TRUE);
+    if ( lenFile == wxInvalidOffset )
+        lenFile = stream.GetLength();
+
+    if ( lenFile == wxInvalidOffset )
+    {
+        m_i_streambuf = NULL;
+        m_lasterror = wxSTREAM_EOF;
+        return;
+    }
+
+    const size_t len = wx_truncate_cast(size_t, lenFile);
+    wxASSERT_MSG( (wxFileOffset)len == lenFile, wxT("huge files not supported") );
+
+    m_i_streambuf = new wxStreamBuffer(wxStreamBuffer::read);
+    m_i_streambuf->SetBufferIO(len); // create buffer
+    stream.Read(m_i_streambuf->GetBufferStart(), len);
+    m_i_streambuf->SetIntPosition(0); // seek to start pos
+    m_i_streambuf->Fixed(true);
+    m_length = stream.LastRead();
+}

 
 

-  m_length = len;
+bool wxMemoryInputStream::CanRead() const
+{
+    return m_i_streambuf->GetIntPosition() != m_length;

 }
 
 wxMemoryInputStream::~wxMemoryInputStream()
 {
 }
 
 wxMemoryInputStream::~wxMemoryInputStream()
 {

-  delete m_i_streambuf;
+    delete m_i_streambuf;

 }
 
 char wxMemoryInputStream::Peek()
 {
 }
 
 char wxMemoryInputStream::Peek()
 {

-  return m_i_streambuf->GetBufferStart()[m_i_streambuf->GetIntPosition()];
+    char *buf = (char *)m_i_streambuf->GetBufferStart();
+    size_t pos = m_i_streambuf->GetIntPosition();
+    if ( pos == m_length )
+    {
+        m_lasterror = wxSTREAM_READ_ERROR;
+
+        return 0;
+    }
+
+    return buf[pos];

 }
 
 size_t wxMemoryInputStream::OnSysRead(void *buffer, size_t nbytes)
 }
 
 size_t wxMemoryInputStream::OnSysRead(void *buffer, size_t nbytes)

-{ 
-  size_t bufsize = m_i_streambuf->GetBufferEnd() - m_i_streambuf->GetBufferStart();
-  size_t oldpos = m_i_streambuf->GetIntPosition();
-  m_i_streambuf->Read(buffer, nbytes);
-  size_t newpos = m_i_streambuf->GetIntPosition();
-  if (newpos == 0) return bufsize - oldpos;
-  else return newpos - oldpos;
+{
+    size_t pos = m_i_streambuf->GetIntPosition();
+    if ( pos == m_length )
+    {
+        m_lasterror = wxSTREAM_EOF;
+
+        return 0;
+    }
+
+    m_i_streambuf->Read(buffer, nbytes);
+    m_lasterror = wxSTREAM_NO_ERROR;
+
+    return m_i_streambuf->GetIntPosition() - pos;

 }
 
 }
 

-off_t wxMemoryInputStream::OnSysSeek(off_t pos, wxSeekMode mode)
+wxFileOffset wxMemoryInputStream::OnSysSeek(wxFileOffset pos, wxSeekMode mode)

 {
 {

-  return m_i_streambuf->Seek(pos, mode);
+    return m_i_streambuf->Seek(pos, mode);

 }
 
 }
 

-off_t wxMemoryInputStream::OnSysTell() const
+wxFileOffset wxMemoryInputStream::OnSysTell() const

 {
 {

-  return m_i_streambuf->Tell();
+    return m_i_streambuf->Tell();

 }
 
 // ----------------------------------------------------------------------------
 // wxMemoryOutputStream
 // ----------------------------------------------------------------------------
 
 }
 
 // ----------------------------------------------------------------------------
 // wxMemoryOutputStream
 // ----------------------------------------------------------------------------
 

-wxMemoryOutputStream::wxMemoryOutputStream(char *data, size_t len)
-  : wxOutputStream()
+IMPLEMENT_DYNAMIC_CLASS(wxMemoryOutputStream, wxOutputStream)
+
+wxMemoryOutputStream::wxMemoryOutputStream(void *data, size_t len)

 {
 {

-  m_o_streambuf = new wxStreamBuffer(wxStreamBuffer::write);
-  if (data)
-    m_o_streambuf->SetBufferIO(data, data+len);
-  m_o_streambuf->Fixed(FALSE);
-  m_o_streambuf->Flushable(FALSE);
+    m_o_streambuf = new wxStreamBuffer(wxStreamBuffer::write);
+    if ( data )
+        m_o_streambuf->SetBufferIO(data, len);
+    m_o_streambuf->Fixed(false);
+    m_o_streambuf->Flushable(false);

 }
 
 wxMemoryOutputStream::~wxMemoryOutputStream()
 {
 }
 
 wxMemoryOutputStream::~wxMemoryOutputStream()
 {

-  delete m_o_streambuf;
+    delete m_o_streambuf;

 }
 
 size_t wxMemoryOutputStream::OnSysWrite(const void *buffer, size_t nbytes)
 {
 }
 
 size_t wxMemoryOutputStream::OnSysWrite(const void *buffer, size_t nbytes)
 {

-  size_t bufsize = m_o_streambuf->GetBufferEnd() - m_o_streambuf->GetBufferStart();
-  size_t oldpos = m_o_streambuf->GetIntPosition();
-  m_o_streambuf->Write(buffer, nbytes);
-  size_t newpos = m_o_streambuf->GetIntPosition();
-  if (newpos == 0) return bufsize - oldpos;
-  else return newpos - oldpos;
+    size_t oldpos = m_o_streambuf->GetIntPosition();
+    m_o_streambuf->Write(buffer, nbytes);
+    size_t newpos = m_o_streambuf->GetIntPosition();
+
+    // FIXME can someone please explain what this does? (VZ)
+    if ( !newpos )
+        newpos = m_o_streambuf->GetBufferSize();
+
+    return newpos - oldpos;

 }
 
 }
 

-off_t wxMemoryOutputStream::OnSysSeek(off_t pos, wxSeekMode mode)
+wxFileOffset wxMemoryOutputStream::OnSysSeek(wxFileOffset pos, wxSeekMode mode)

 {
 {

-  return m_o_streambuf->Seek(pos, mode);
+    return m_o_streambuf->Seek(pos, mode);

 }
 
 }
 

-off_t wxMemoryOutputStream::OnSysTell() const
+wxFileOffset wxMemoryOutputStream::OnSysTell() const

 {
 {

-  return m_o_streambuf->Tell();
+    return m_o_streambuf->Tell();

 }
 
 }
 

-size_t wxMemoryOutputStream::CopyTo(char *buffer, size_t len) const
+size_t wxMemoryOutputStream::CopyTo(void *buffer, size_t len) const

 {
 {

-  if (!buffer)
-    return 0;
+    wxCHECK_MSG( buffer, 0, wxT("must have buffer to CopyTo") );
+
+    if ( len > GetSize() )
+        len = GetSize();

 
 

-  if (len > GetSize())
-    len = GetSize();
+    memcpy(buffer, m_o_streambuf->GetBufferStart(), len);

 
 

-  memcpy(buffer, m_o_streambuf->GetBufferStart(), len);
-  return len;
+    return len;

 }
 
 }
 

-#endif
+#endif // wxUSE_STREAMS