src/common/mstream.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        mstream.cpp
   3 // Purpose:     "Memory stream" classes
   4 // Author:      Guilhem Lavaux
   5 // Modified by:
   6 // Created:     04/01/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Guilhem Lavaux
   9 // Licence:     wxWindows license
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifdef __GNUG__
  13 #pragma implementation "mstream.h"
  14 #endif
  15
  16 // For compilers that support precompilation, includes "wx.h".
  17 #include "wx/wxprec.h"
  18
  19 #ifdef __BORLANDC__
  20   #pragma hdrstop
  21 #endif
  22
  23 #if wxUSE_STREAMS
  24
  25 #include <stdlib.h>
  26 #include "wx/stream.h"
  27 #include "wx/mstream.h"
  28
  29 // ----------------------------------------------------------------------------
  30 // wxMemoryInputStream
  31 // ----------------------------------------------------------------------------
  32
  33 wxMemoryInputStream::wxMemoryInputStream(const char *data, size_t len)
  34   : wxInputStream()
  35 {
  36   m_i_streambuf = new wxStreamBuffer(wxStreamBuffer::read);
  37   m_i_streambuf->SetBufferIO((char*) data, (char*) (data+len));
  38   m_i_streambuf->SetIntPosition(0); // seek to start pos
  39   m_i_streambuf->Fixed(TRUE);
  40
  41   m_length = len;
  42 }
  43
  44 wxMemoryInputStream::~wxMemoryInputStream()
  45 {
  46   delete m_i_streambuf;
  47 }
  48
  49 char wxMemoryInputStream::Peek()
  50 {
  51   return m_i_streambuf->GetBufferStart()[m_i_streambuf->GetIntPosition()];
  52 }
  53
  54 bool wxMemoryInputStream::Eof() const
  55 {
  56     return m_i_streambuf->GetBufferPos() == m_i_streambuf->GetBufferEnd();
  57 }
  58
  59 size_t wxMemoryInputStream::OnSysRead(void *buffer, size_t nbytes)
  60 {
  61     size_t pos = m_i_streambuf->GetIntPosition();
  62     if ( pos == m_length )
  63     {
  64         m_lasterror = wxSTREAM_EOF;
  65
  66         return 0;
  67     }
  68
  69     m_i_streambuf->Read(buffer, nbytes);
  70     m_lasterror = wxSTREAM_NOERROR;
  71
  72     return m_i_streambuf->GetIntPosition() - pos;
  73 }
  74
  75 off_t wxMemoryInputStream::OnSysSeek(off_t pos, wxSeekMode mode)
  76 {
  77   return m_i_streambuf->Seek(pos, mode);
  78 }
  79
  80 off_t wxMemoryInputStream::OnSysTell() const
  81 {
  82   return m_i_streambuf->Tell();
  83 }
  84
  85 // ----------------------------------------------------------------------------
  86 // wxMemoryOutputStream
  87 // ----------------------------------------------------------------------------
  88
  89 wxMemoryOutputStream::wxMemoryOutputStream(char *data, size_t len)
  90   : wxOutputStream()
  91 {
  92   m_o_streambuf = new wxStreamBuffer(wxStreamBuffer::write);
  93   if (data)
  94     m_o_streambuf->SetBufferIO(data, data+len);
  95   m_o_streambuf->Fixed(FALSE);
  96   m_o_streambuf->Flushable(FALSE);
  97 }
  98
  99 wxMemoryOutputStream::~wxMemoryOutputStream()
 100 {
 101   delete m_o_streambuf;
 102 }
 103
 104 size_t wxMemoryOutputStream::OnSysWrite(const void *buffer, size_t nbytes)
 105 {
 106   size_t bufsize = m_o_streambuf->GetBufferEnd() - m_o_streambuf->GetBufferStart();
 107   size_t oldpos = m_o_streambuf->GetIntPosition();
 108   m_o_streambuf->Write(buffer, nbytes);
 109   size_t newpos = m_o_streambuf->GetIntPosition();
 110   if (newpos == 0) return bufsize - oldpos;
 111   else return newpos - oldpos;
 112 }
 113
 114 off_t wxMemoryOutputStream::OnSysSeek(off_t pos, wxSeekMode mode)
 115 {
 116   return m_o_streambuf->Seek(pos, mode);
 117 }
 118
 119 off_t wxMemoryOutputStream::OnSysTell() const
 120 {
 121   return m_o_streambuf->Tell();
 122 }
 123
 124 size_t wxMemoryOutputStream::CopyTo(char *buffer, size_t len) const
 125 {
 126   if (!buffer)
 127     return 0;
 128
 129   if (len > GetSize())
 130     len = GetSize();
 131
 132   memcpy(buffer, m_o_streambuf->GetBufferStart(), len);
 133   return len;
 134 }
 135
 136 #endif