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       m_inflate->zalloc = (alloc_func)0;
  61       m_inflate->zfree = (free_func)0;
  62       m_inflate->opaque = (voidpf)0;
  63       m_inflate->avail_in = 0;
  64       m_inflate->next_in = NULL;
  65       m_inflate->next_out = NULL;
  66
  67       wxASSERT((flags & ~(wxZLIB_ZLIB | wxZLIB_GZIP)) == 0);
  68
  69       // when autodetecting between gzip & zlib, silently drop gzip flag
  70       // if the version of zlib doesn't support it
  71       if (flags == (wxZLIB_ZLIB | wxZLIB_GZIP)
  72               && strcmp(zlib_version, "1.2.") < 0)
  73         flags &= ~wxZLIB_GZIP;
  74
  75       int bits = flags ? MAX_WBITS : -MAX_WBITS;
  76       if (flags & wxZLIB_GZIP)
  77         bits |= (flags & wxZLIB_ZLIB) ? 0x20 : 0x10;
  78
  79       if (inflateInit2(m_inflate, bits) == Z_OK)
  80         return;
  81     }
  82   }
  83
  84   wxLogError(_("Can't initialize zlib inflate stream."));
  85   m_lasterror = wxSTREAM_READ_ERROR;
  86 }
  87
  88 wxZlibInputStream::~wxZlibInputStream()
  89 {
  90   inflateEnd(m_inflate);
  91   delete m_inflate;
  92
  93   delete [] m_z_buffer;
  94 }
  95
  96 size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size)
  97 {
  98   wxASSERT_MSG(m_inflate && m_z_buffer, wxT("Inflate stream not open"));
  99
 100   if (!m_inflate || !m_z_buffer)
 101     m_lasterror = wxSTREAM_READ_ERROR;
 102   if (!IsOk() || !size)
 103     return 0;
 104
 105   int err = Z_OK;
 106   m_inflate->next_out = (unsigned char *)buffer;
 107   m_inflate->avail_out = size;
 108
 109   while (err == Z_OK && m_inflate->avail_out > 0) {
 110     if (m_inflate->avail_in == 0) {
 111       m_parent_i_stream->Read(m_z_buffer, m_z_size);
 112       m_inflate->next_in = m_z_buffer;
 113       m_inflate->avail_in = m_parent_i_stream->LastRead();
 114
 115       if (m_inflate->avail_in == 0) {
 116         if (m_parent_i_stream->Eof())
 117           wxLogError(_("Can't read inflate stream: unexpected EOF in underlying stream."));
 118         m_lasterror = wxSTREAM_READ_ERROR;
 119         break;
 120       }
 121     }
 122     err = inflate(m_inflate, Z_NO_FLUSH);
 123   }
 124
 125   if (err == Z_STREAM_END) {
 126     // Unread any data taken from past the end of the deflate stream, so that
 127     // any additional data can be read from the underlying stream (the crc
 128     // in a gzip for example)
 129     if (m_inflate->avail_in) {
 130       m_parent_i_stream->Ungetch(m_inflate->next_in, m_inflate->avail_in);
 131       m_inflate->avail_in = 0;
 132     }
 133     m_lasterror = wxSTREAM_EOF;
 134   } else if (err != Z_OK) {
 135     wxString msg(m_inflate->msg, *wxConvCurrent);
 136     if (!msg)
 137       msg.Format(_("zlib error %d"), err);
 138     wxLogError(_("Can't read from inflate stream: %s\n"), msg.c_str());
 139     m_lasterror = wxSTREAM_READ_ERROR;
 140   }
 141
 142   size -= m_inflate->avail_out;
 143   m_pos += size;
 144   return size;
 145 }
 146
 147 //////////////////////
 148 // wxZlibOutputStream
 149 //////////////////////
 150
 151 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream,
 152                                        int level,
 153                                        int flags)
 154  : wxFilterOutputStream(stream)
 155 {
 156   m_deflate = NULL;
 157   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 158   m_z_size = ZSTREAM_BUFFER_SIZE;
 159   m_pos = 0;
 160
 161   if ( level == -1 )
 162   {
 163     level = Z_DEFAULT_COMPRESSION;
 164   }
 165   else
 166   {
 167     wxASSERT_MSG(level >= 0 && level <= 9, wxT("wxZlibOutputStream compression level must be between 0 and 9!"));
 168   }
 169
 170   if (m_z_buffer) {
 171      m_deflate = new z_stream_s;
 172
 173      if (m_deflate) {
 174         m_deflate->zalloc = (alloc_func)0;
 175         m_deflate->zfree = (free_func)0;
 176         m_deflate->opaque = (voidpf)0;
 177         m_deflate->avail_in = 0;
 178         m_deflate->next_out = m_z_buffer;
 179         m_deflate->avail_out = m_z_size;
 180
 181         wxASSERT(flags == 0 || flags == wxZLIB_ZLIB || flags == wxZLIB_GZIP);
 182
 183         int bits = flags ? MAX_WBITS : -MAX_WBITS;
 184         if (flags & wxZLIB_GZIP)
 185             bits |= 0x10;
 186
 187         if (deflateInit2(m_deflate, level, Z_DEFLATED, bits,
 188                          8, Z_DEFAULT_STRATEGY) == Z_OK)
 189           return;
 190      }
 191   }
 192
 193   wxLogError(_("Can't initialize zlib deflate stream."));
 194   m_lasterror = wxSTREAM_WRITE_ERROR;
 195 }
 196
 197 wxZlibOutputStream::~wxZlibOutputStream()
 198 {
 199   if (m_deflate && m_z_buffer)
 200     DoFlush(true);
 201   deflateEnd(m_deflate);
 202   delete m_deflate;
 203
 204   delete[] m_z_buffer;
 205 }
 206
 207 void wxZlibOutputStream::DoFlush(bool final)
 208 {
 209   wxASSERT_MSG(m_deflate && m_z_buffer, wxT("Deflate stream not open"));
 210
 211   if (!m_deflate || !m_z_buffer)
 212     m_lasterror = wxSTREAM_WRITE_ERROR;
 213   if (!IsOk())
 214     return;
 215
 216   int err = Z_OK;
 217   bool done = false;
 218
 219   while (err == Z_OK || err == Z_STREAM_END) {
 220     size_t len = m_z_size  - m_deflate->avail_out;
 221     if (len) {
 222       if (m_parent_o_stream->Write(m_z_buffer, len).LastWrite() != len) {
 223         m_lasterror = wxSTREAM_WRITE_ERROR;
 224         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 225         break;
 226       }
 227       m_deflate->next_out = m_z_buffer;
 228       m_deflate->avail_out = m_z_size;
 229     }
 230
 231     if (done)
 232       break;
 233     err = deflate(m_deflate, final ? Z_FINISH : Z_FULL_FLUSH);
 234     done = m_deflate->avail_out != 0 || err == Z_STREAM_END;
 235   }
 236 }
 237
 238 size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size)
 239 {
 240   wxASSERT_MSG(m_deflate && m_z_buffer, wxT("Deflate stream not open"));
 241
 242   if (!m_deflate || !m_z_buffer)
 243     m_lasterror = wxSTREAM_WRITE_ERROR;
 244   if (!IsOk() || !size)
 245     return 0;
 246
 247   int err = Z_OK;
 248   m_deflate->next_in = (unsigned char *)buffer;
 249   m_deflate->avail_in = size;
 250
 251   while (err == Z_OK && m_deflate->avail_in > 0) {
 252     if (m_deflate->avail_out == 0) {
 253       m_parent_o_stream->Write(m_z_buffer, m_z_size);
 254       if (m_parent_o_stream->LastWrite() != m_z_size) {
 255         m_lasterror = wxSTREAM_WRITE_ERROR;
 256         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 257         break;
 258       }
 259
 260       m_deflate->next_out = m_z_buffer;
 261       m_deflate->avail_out = m_z_size;
 262     }
 263
 264     err = deflate(m_deflate, Z_NO_FLUSH);
 265   }
 266
 267   if (err != Z_OK) {
 268     m_lasterror = wxSTREAM_WRITE_ERROR;
 269     wxString msg(m_deflate->msg, *wxConvCurrent);
 270     if (!msg)
 271       msg.Format(_("zlib error %d"), err);
 272     wxLogError(_("Can't write to deflate stream: %s\n"), msg.c_str());
 273   }
 274
 275   size -= m_deflate->avail_in;
 276   m_pos += size;
 277   return size;
 278 }
 279
 280 #endif
 281   // wxUSE_ZLIB && wxUSE_STREAMS
 282