src/common/zstream.cpp

   1 //////////////////////////////////////////////////////////////////////////////
   2 // Name:        zstream.cpp
   3 // Purpose:     Compressed stream classes
   4 // Author:      Guilhem Lavaux
   5 // Modified by: Mike Wetherell
   6 // Created:     11/07/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Guilhem Lavaux
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
  13 #pragma implementation "zstream.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_ZLIB && wxUSE_STREAMS
  24
  25 #include "wx/zstream.h"
  26 #include "wx/utils.h"
  27 #include "wx/intl.h"
  28 #include "wx/log.h"
  29
  30 // normally, the compiler options should contain -I../zlib, but it is
  31 // apparently not the case for all MSW makefiles and so, unless we use
  32 // configure (which defines __WX_SETUP_H__) or it is explicitly overridden by
  33 // the user (who can define wxUSE_ZLIB_H_IN_PATH), we hardcode the path here
  34 #if defined(__WXMSW__) && !defined(__WX_SETUP_H__) && !defined(wxUSE_ZLIB_H_IN_PATH)
  35    #include "../zlib/zlib.h"
  36 #else
  37    #include "zlib.h"
  38 #endif
  39
  40 enum {
  41     ZSTREAM_BUFFER_SIZE = 16384
  42 };
  43
  44 //////////////////////
  45 // wxZlibInputStream
  46 //////////////////////
  47
  48 wxZlibInputStream::wxZlibInputStream(wxInputStream& stream, int flags)
  49   : wxFilterInputStream(stream)
  50 {
  51   m_inflate = NULL;
  52   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
  53   m_z_size = ZSTREAM_BUFFER_SIZE;
  54   m_pos = 0;
  55
  56   if (m_z_buffer) {
  57     m_inflate = new z_stream_s;
  58
  59     if (m_inflate) {
  60       memset(m_inflate, 0, sizeof(z_stream_s));
  61
  62       wxASSERT((flags & ~(wxZLIB_ZLIB | wxZLIB_GZIP)) == 0);
  63
  64       // when autodetecting between gzip & zlib, silently drop gzip flag
  65       // if the version of zlib doesn't support it
  66       if (flags == (wxZLIB_ZLIB | wxZLIB_GZIP)
  67               && strcmp(zlib_version, "1.2.") < 0)
  68         flags &= ~wxZLIB_GZIP;
  69
  70       int bits = flags ? MAX_WBITS : -MAX_WBITS;
  71       if (flags & wxZLIB_GZIP)
  72         bits |= (flags & wxZLIB_ZLIB) ? 0x20 : 0x10;
  73
  74       if (inflateInit2(m_inflate, bits) == Z_OK)
  75         return;
  76     }
  77   }
  78
  79   wxLogError(_("Can't initialize zlib inflate stream."));
  80   m_lasterror = wxSTREAM_READ_ERROR;
  81 }
  82
  83 wxZlibInputStream::~wxZlibInputStream()
  84 {
  85   inflateEnd(m_inflate);
  86   delete m_inflate;
  87
  88   delete [] m_z_buffer;
  89 }
  90
  91 size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size)
  92 {
  93   wxASSERT_MSG(m_inflate && m_z_buffer, wxT("Inflate stream not open"));
  94
  95   if (!m_inflate || !m_z_buffer)
  96     m_lasterror = wxSTREAM_READ_ERROR;
  97   if (!IsOk() || !size)
  98     return 0;
  99
 100   int err = Z_OK;
 101   m_inflate->next_out = (unsigned char *)buffer;
 102   m_inflate->avail_out = size;
 103
 104   while (err == Z_OK && m_inflate->avail_out > 0) {
 105     if (m_inflate->avail_in == 0) {
 106       m_parent_i_stream->Read(m_z_buffer, m_z_size);
 107       m_inflate->next_in = m_z_buffer;
 108       m_inflate->avail_in = m_parent_i_stream->LastRead();
 109
 110       if (m_inflate->avail_in == 0) {
 111         if (m_parent_i_stream->Eof())
 112           wxLogError(_("Can't read inflate stream: unexpected EOF in underlying stream."));
 113         m_lasterror = wxSTREAM_READ_ERROR;
 114         break;
 115       }
 116     }
 117     err = inflate(m_inflate, Z_NO_FLUSH);
 118   }
 119
 120   if (err == Z_STREAM_END) {
 121     // Unread any data taken from past the end of the deflate stream, so that
 122     // any additional data can be read from the underlying stream (the crc
 123     // in a gzip for example)
 124     if (m_inflate->avail_in) {
 125       m_parent_i_stream->Ungetch(m_inflate->next_in, m_inflate->avail_in);
 126       m_inflate->avail_in = 0;
 127     }
 128     m_lasterror = wxSTREAM_EOF;
 129   } else if (err != Z_OK) {
 130     wxString msg(m_inflate->msg, *wxConvCurrent);
 131     if (!msg)
 132       msg.Format(_("zlib error %d"), err);
 133     wxLogError(_("Can't read from inflate stream: %s\n"), msg.c_str());
 134     m_lasterror = wxSTREAM_READ_ERROR;
 135   }
 136
 137   size -= m_inflate->avail_out;
 138   m_pos += size;
 139   return size;
 140 }
 141
 142 //////////////////////
 143 // wxZlibOutputStream
 144 //////////////////////
 145
 146 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream,
 147                                        int level,
 148                                        int flags)
 149  : wxFilterOutputStream(stream)
 150 {
 151   m_deflate = NULL;
 152   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 153   m_z_size = ZSTREAM_BUFFER_SIZE;
 154   m_pos = 0;
 155
 156   if ( level == -1 )
 157   {
 158     level = Z_DEFAULT_COMPRESSION;
 159   }
 160   else
 161   {
 162     wxASSERT_MSG(level >= 0 && level <= 9, wxT("wxZlibOutputStream compression level must be between 0 and 9!"));
 163   }
 164
 165   if (m_z_buffer) {
 166      m_deflate = new z_stream_s;
 167
 168      if (m_deflate) {
 169         memset(m_deflate, 0, sizeof(z_stream_s));
 170         m_deflate->next_out = m_z_buffer;
 171         m_deflate->avail_out = m_z_size;
 172
 173         wxASSERT(flags == 0 || flags == wxZLIB_ZLIB || flags == wxZLIB_GZIP);
 174
 175         int bits = flags ? MAX_WBITS : -MAX_WBITS;
 176         if (flags & wxZLIB_GZIP)
 177             bits |= 0x10;
 178
 179         if (deflateInit2(m_deflate, level, Z_DEFLATED, bits,
 180                          8, Z_DEFAULT_STRATEGY) == Z_OK)
 181           return;
 182      }
 183   }
 184
 185   wxLogError(_("Can't initialize zlib deflate stream."));
 186   m_lasterror = wxSTREAM_WRITE_ERROR;
 187 }
 188
 189 wxZlibOutputStream::~wxZlibOutputStream()
 190 {
 191   if (m_deflate && m_z_buffer)
 192     DoFlush(true);
 193   deflateEnd(m_deflate);
 194   delete m_deflate;
 195
 196   delete[] m_z_buffer;
 197 }
 198
 199 void wxZlibOutputStream::DoFlush(bool final)
 200 {
 201   wxASSERT_MSG(m_deflate && m_z_buffer, wxT("Deflate stream not open"));
 202
 203   if (!m_deflate || !m_z_buffer)
 204     m_lasterror = wxSTREAM_WRITE_ERROR;
 205   if (!IsOk())
 206     return;
 207
 208   int err = Z_OK;
 209   bool done = false;
 210
 211   while (err == Z_OK || err == Z_STREAM_END) {
 212     size_t len = m_z_size  - m_deflate->avail_out;
 213     if (len) {
 214       if (m_parent_o_stream->Write(m_z_buffer, len).LastWrite() != len) {
 215         m_lasterror = wxSTREAM_WRITE_ERROR;
 216         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 217         break;
 218       }
 219       m_deflate->next_out = m_z_buffer;
 220       m_deflate->avail_out = m_z_size;
 221     }
 222
 223     if (done)
 224       break;
 225     err = deflate(m_deflate, final ? Z_FINISH : Z_FULL_FLUSH);
 226     done = m_deflate->avail_out != 0 || err == Z_STREAM_END;
 227   }
 228 }
 229
 230 size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size)
 231 {
 232   wxASSERT_MSG(m_deflate && m_z_buffer, wxT("Deflate stream not open"));
 233
 234   if (!m_deflate || !m_z_buffer)
 235     m_lasterror = wxSTREAM_WRITE_ERROR;
 236   if (!IsOk() || !size)
 237     return 0;
 238
 239   int err = Z_OK;
 240   m_deflate->next_in = (unsigned char *)buffer;
 241   m_deflate->avail_in = size;
 242
 243   while (err == Z_OK && m_deflate->avail_in > 0) {
 244     if (m_deflate->avail_out == 0) {
 245       m_parent_o_stream->Write(m_z_buffer, m_z_size);
 246       if (m_parent_o_stream->LastWrite() != m_z_size) {
 247         m_lasterror = wxSTREAM_WRITE_ERROR;
 248         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 249         break;
 250       }
 251
 252       m_deflate->next_out = m_z_buffer;
 253       m_deflate->avail_out = m_z_size;
 254     }
 255
 256     err = deflate(m_deflate, Z_NO_FLUSH);
 257   }
 258
 259   if (err != Z_OK) {
 260     m_lasterror = wxSTREAM_WRITE_ERROR;
 261     wxString msg(m_deflate->msg, *wxConvCurrent);
 262     if (!msg)
 263       msg.Format(_("zlib error %d"), err);
 264     wxLogError(_("Can't write to deflate stream: %s\n"), msg.c_str());
 265   }
 266
 267   size -= m_deflate->avail_in;
 268   m_pos += size;
 269   return size;
 270 }
 271
 272 #endif
 273   // wxUSE_ZLIB && wxUSE_STREAMS
 274