src/common/sstream.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        common/sstream.cpp
   3 // Purpose:     string-based streams implementation
   4 // Author:      Vadim Zeitlin
   5 // Modified by: Ryan Norton (UTF8 UNICODE)
   6 // Created:     2004-09-19
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 2004 Vadim Zeitlin <vadim@wxwindows.org>
   9 // Licence:     wxWindows licence
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 // For compilers that support precompilation, includes "wx.h".
  21 #include "wx/wxprec.h"
  22
  23 #ifdef __BORLANDC__
  24     #pragma hdrstop
  25 #endif
  26
  27 #if wxUSE_STREAMS
  28
  29 #include "wx/sstream.h"
  30
  31 // ============================================================================
  32 // wxStringInputStream implementation
  33 // ============================================================================
  34
  35 // ----------------------------------------------------------------------------
  36 // construction/destruction
  37 // ----------------------------------------------------------------------------
  38
  39 // TODO:  Do we want to include the null char in the stream?  If so then
  40 // just add +1 to m_len in the ctor
  41 wxStringInputStream::wxStringInputStream(const wxString& s)
  42 #if wxUSE_UNICODE
  43     // FIXME-UTF8: use wxCharBufferWithLength if we have it
  44     : m_str(s), m_buf(s.utf8_str()), m_len(strlen(m_buf))
  45 #else
  46     : m_str(s), m_buf(s.mb_str()), m_len(s.length())
  47 #endif
  48 {
  49 #if wxUSE_UNICODE
  50     wxASSERT_MSG(m_buf.data() != NULL, _T("Could not convert string to UTF8!"));
  51 #endif
  52     m_pos = 0;
  53 }
  54
  55 // ----------------------------------------------------------------------------
  56 // getlength
  57 // ----------------------------------------------------------------------------
  58
  59 wxFileOffset wxStringInputStream::GetLength() const
  60 {
  61     return m_len;
  62 }
  63
  64 // ----------------------------------------------------------------------------
  65 // seek/tell
  66 // ----------------------------------------------------------------------------
  67
  68 wxFileOffset wxStringInputStream::OnSysSeek(wxFileOffset ofs, wxSeekMode mode)
  69 {
  70     switch ( mode )
  71     {
  72         case wxFromStart:
  73             // nothing to do, ofs already ok
  74             break;
  75
  76         case wxFromEnd:
  77             ofs += m_len;
  78             break;
  79
  80         case wxFromCurrent:
  81             ofs += m_pos;
  82             break;
  83
  84         default:
  85             wxFAIL_MSG( _T("invalid seek mode") );
  86             return wxInvalidOffset;
  87     }
  88
  89     if ( ofs < 0 || ofs > static_cast<wxFileOffset>(m_len) )
  90         return wxInvalidOffset;
  91
  92     // FIXME: this can't be right
  93     m_pos = wx_truncate_cast(size_t, ofs);
  94
  95     return ofs;
  96 }
  97
  98 wxFileOffset wxStringInputStream::OnSysTell() const
  99 {
 100     return static_cast<wxFileOffset>(m_pos);
 101 }
 102
 103 // ----------------------------------------------------------------------------
 104 // actual IO
 105 // ----------------------------------------------------------------------------
 106
 107 size_t wxStringInputStream::OnSysRead(void *buffer, size_t size)
 108 {
 109     const size_t sizeMax = m_len - m_pos;
 110
 111     if ( size >= sizeMax )
 112     {
 113         if ( sizeMax == 0 )
 114         {
 115             m_lasterror = wxSTREAM_EOF;
 116             return 0;
 117         }
 118
 119         size = sizeMax;
 120     }
 121
 122     memcpy(buffer, m_buf.data() + m_pos, size);
 123     m_pos += size;
 124
 125     return size;
 126 }
 127
 128 // ============================================================================
 129 // wxStringOutputStream implementation
 130 // ============================================================================
 131
 132 // ----------------------------------------------------------------------------
 133 // seek/tell
 134 // ----------------------------------------------------------------------------
 135
 136 wxFileOffset wxStringOutputStream::OnSysTell() const
 137 {
 138     return static_cast<wxFileOffset>(m_pos);
 139 }
 140
 141 // ----------------------------------------------------------------------------
 142 // actual IO
 143 // ----------------------------------------------------------------------------
 144
 145 size_t wxStringOutputStream::OnSysWrite(const void *buffer, size_t size)
 146 {
 147     const char *p = static_cast<const char *>(buffer);
 148
 149 #if wxUSE_UNICODE_WCHAR
 150     // the part of the string we have here may be incomplete, i.e. it can stop
 151     // in the middle of an UTF-8 character and so converting it would fail; if
 152     // this is the case, accumulate the part which we failed to convert until
 153     // we get the rest (and also take into account the part which we might have
 154     // left unconverted before)
 155     const char *src;
 156     size_t srcLen;
 157     if ( m_unconv.GetDataLen() )
 158     {
 159         // append the new data to the data remaining since the last time
 160         m_unconv.AppendData(p, size);
 161         src = m_unconv;
 162         srcLen = m_unconv.GetDataLen();
 163     }
 164     else // no unconverted data left, avoid extra copy
 165     {
 166         src = p;
 167         srcLen = size;
 168     }
 169
 170     size_t wlen;
 171     wxWCharBuffer wbuf(m_conv.cMB2WC(src, srcLen, &wlen));
 172     if ( wbuf )
 173     {
 174         // conversion succeeded, clear the unconverted buffer
 175         m_unconv = wxMemoryBuffer(0);
 176
 177         m_str->append(wbuf, wlen);
 178     }
 179     else // conversion failed
 180     {
 181         // remember unconverted data if there had been none before (otherwise
 182         // we've already got it in the buffer)
 183         if ( src == p )
 184             m_unconv.AppendData(src, srcLen);
 185
 186         // pretend that we wrote the data anyhow, otherwise the caller would
 187         // believe there was an error and this might not be the case, but do
 188         // not update m_pos as m_str hasn't changed
 189         return size;
 190     }
 191 #else // !wxUSE_UNICODE_WCHAR
 192     // no recoding necessary, the data is supposed to already be in UTF-8 (if
 193     // supported) or ASCII otherwise
 194     m_str->append(p, size);
 195 #endif // wxUSE_UNICODE_WCHAR/!wxUSE_UNICODE_WCHAR
 196
 197     // update position
 198     m_pos += size;
 199
 200     // return number of bytes actually written
 201     return size;
 202 }
 203
 204 #endif // wxUSE_STREAMS
 205