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 #ifdef __WIN16__
  42     ZSTREAM_BUFFER_SIZE = 4096
  43 #else
  44     ZSTREAM_BUFFER_SIZE = 16384
  45 #endif
  46 };
  47
  48 //////////////////////
  49 // wxZlibInputStream
  50 //////////////////////
  51
  52 wxZlibInputStream::wxZlibInputStream(wxInputStream& stream, int flags)
  53   : wxFilterInputStream(stream)
  54 {
  55   m_inflate = NULL;
  56   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
  57   m_z_size = ZSTREAM_BUFFER_SIZE;
  58   m_pos = 0;
  59
  60   if (m_z_buffer) {
  61     m_inflate = new z_stream_s;
  62
  63     if (m_inflate) {
  64       m_inflate->zalloc = (alloc_func)0;
  65       m_inflate->zfree = (free_func)0;
  66       m_inflate->opaque = (voidpf)0;
  67       m_inflate->avail_in = 0;
  68       m_inflate->next_in = NULL;
  69       m_inflate->next_out = NULL;
  70
  71       wxASSERT((flags & ~(wxZLIB_ZLIB | wxZLIB_GZIP)) == 0);
  72
  73       // when autodetecting between gzip & zlib, silently drop gzip flag
  74       // if the version of zlib doesn't support it
  75       if (flags == (wxZLIB_ZLIB | wxZLIB_GZIP)
  76               && strcmp(zlib_version, "1.2.") < 0)
  77         flags &= ~wxZLIB_GZIP;
  78
  79       int bits = flags ? MAX_WBITS : -MAX_WBITS;
  80       if (flags & wxZLIB_GZIP)
  81         bits |= (flags & wxZLIB_ZLIB) ? 0x20 : 0x10;
  82
  83       if (inflateInit2(m_inflate, bits) == Z_OK)
  84         return;
  85     }
  86   }
  87
  88   wxLogError(_("Can't initialize zlib inflate stream."));
  89   m_lasterror = wxSTREAM_READ_ERROR;
  90 }
  91
  92 wxZlibInputStream::~wxZlibInputStream()
  93 {
  94   inflateEnd(m_inflate);
  95   delete m_inflate;
  96
  97   delete [] m_z_buffer;
  98 }
  99
 100 size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size)
 101 {
 102   wxASSERT_MSG(m_inflate && m_z_buffer, wxT("Inflate stream not open"));
 103
 104   if (!m_inflate || !m_z_buffer)
 105     m_lasterror = wxSTREAM_READ_ERROR;
 106   if (!IsOk() || !size)
 107     return 0;
 108
 109   int err = Z_OK;
 110   m_inflate->next_out = (unsigned char *)buffer;
 111   m_inflate->avail_out = size;
 112
 113   while (err == Z_OK && m_inflate->avail_out > 0) {
 114     if (m_inflate->avail_in == 0) {
 115       m_parent_i_stream->Read(m_z_buffer, m_z_size);
 116       m_inflate->next_in = m_z_buffer;
 117       m_inflate->avail_in = m_parent_i_stream->LastRead();
 118
 119       if (m_inflate->avail_in == 0) {
 120         if (m_parent_i_stream->Eof())
 121           wxLogError(_("Can't read inflate stream: unexpected EOF in underlying stream."));
 122         m_lasterror = wxSTREAM_READ_ERROR;
 123         break;
 124       }
 125     }
 126     err = inflate(m_inflate, Z_NO_FLUSH);
 127   }
 128
 129   if (err == Z_STREAM_END) {
 130     // Unread any data taken from past the end of the deflate stream, so that
 131     // any additional data can be read from the underlying stream (the crc
 132     // in a gzip for example)
 133     if (m_inflate->avail_in) {
 134       m_parent_i_stream->Ungetch(m_inflate->next_in, m_inflate->avail_in);
 135       m_inflate->avail_in = 0;
 136     }
 137     m_lasterror = wxSTREAM_EOF;
 138   } else if (err != Z_OK) {
 139     wxString msg(m_inflate->msg, *wxConvCurrent);
 140     if (!msg)
 141       msg.Format(_("zlib error %d"), err);
 142     wxLogError(_("Can't read from inflate stream: %s\n"), msg.c_str());
 143     m_lasterror = wxSTREAM_READ_ERROR;
 144   }
 145
 146   size -= m_inflate->avail_out;
 147   m_pos += size;
 148   return size;
 149 }
 150
 151 //////////////////////
 152 // wxZlibOutputStream
 153 //////////////////////
 154
 155 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream,
 156                                        int level,
 157                                        int flags)
 158  : wxFilterOutputStream(stream)
 159 {
 160   m_deflate = NULL;
 161   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 162   m_z_size = ZSTREAM_BUFFER_SIZE;
 163   m_pos = 0;
 164
 165   if ( level == -1 )
 166   {
 167     level = Z_DEFAULT_COMPRESSION;
 168   }
 169   else
 170   {
 171     wxASSERT_MSG(level >= 0 && level <= 9, wxT("wxZlibOutputStream compression level must be between 0 and 9!"));
 172   }
 173
 174   if (m_z_buffer) {
 175      m_deflate = new z_stream_s;
 176
 177      if (m_deflate) {
 178         m_deflate->zalloc = (alloc_func)0;
 179         m_deflate->zfree = (free_func)0;
 180         m_deflate->opaque = (voidpf)0;
 181         m_deflate->avail_in = 0;
 182         m_deflate->next_out = m_z_buffer;
 183         m_deflate->avail_out = m_z_size;
 184
 185         wxASSERT(flags == 0 || flags == wxZLIB_ZLIB || flags == wxZLIB_GZIP);
 186
 187         int bits = flags ? MAX_WBITS : -MAX_WBITS;
 188         if (flags & wxZLIB_GZIP)
 189             bits |= 0x10;
 190
 191         if (deflateInit2(m_deflate, level, Z_DEFLATED, bits,
 192                          8, Z_DEFAULT_STRATEGY) == Z_OK)
 193           return;
 194      }
 195   }
 196
 197   wxLogError(_("Can't initialize zlib deflate stream."));
 198   m_lasterror = wxSTREAM_WRITE_ERROR;
 199 }
 200
 201 wxZlibOutputStream::~wxZlibOutputStream()
 202 {
 203   if (m_deflate && m_z_buffer)
 204     DoFlush(true);
 205   deflateEnd(m_deflate);
 206   delete m_deflate;
 207
 208   delete[] m_z_buffer;
 209 }
 210
 211 void wxZlibOutputStream::DoFlush(bool final)
 212 {
 213   wxASSERT_MSG(m_deflate && m_z_buffer, wxT("Deflate stream not open"));
 214
 215   if (!m_deflate || !m_z_buffer)
 216     m_lasterror = wxSTREAM_WRITE_ERROR;
 217   if (!IsOk())
 218     return;
 219
 220   int err = Z_OK;
 221   bool done = false;
 222
 223   while (err == Z_OK || err == Z_STREAM_END) {
 224     size_t len = m_z_size  - m_deflate->avail_out;
 225     if (len) {
 226       if (m_parent_o_stream->Write(m_z_buffer, len).LastWrite() != len) {
 227         m_lasterror = wxSTREAM_WRITE_ERROR;
 228         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 229         break;
 230       }
 231       m_deflate->next_out = m_z_buffer;
 232       m_deflate->avail_out = m_z_size;
 233     }
 234
 235     if (done)
 236       break;
 237     err = deflate(m_deflate, final ? Z_FINISH : Z_FULL_FLUSH);
 238     done = m_deflate->avail_out != 0 || err == Z_STREAM_END;
 239   }
 240 }
 241
 242 size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size)
 243 {
 244   wxASSERT_MSG(m_deflate && m_z_buffer, wxT("Deflate stream not open"));
 245
 246   if (!m_deflate || !m_z_buffer)
 247     m_lasterror = wxSTREAM_WRITE_ERROR;
 248   if (!IsOk() || !size)
 249     return 0;
 250
 251   int err = Z_OK;
 252   m_deflate->next_in = (unsigned char *)buffer;
 253   m_deflate->avail_in = size;
 254
 255   while (err == Z_OK && m_deflate->avail_in > 0) {
 256     if (m_deflate->avail_out == 0) {
 257       m_parent_o_stream->Write(m_z_buffer, m_z_size);
 258       if (m_parent_o_stream->LastWrite() != m_z_size) {
 259         m_lasterror = wxSTREAM_WRITE_ERROR;
 260         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 261         break;
 262       }
 263
 264       m_deflate->next_out = m_z_buffer;
 265       m_deflate->avail_out = m_z_size;
 266     }
 267
 268     err = deflate(m_deflate, Z_NO_FLUSH);
 269   }
 270
 271   if (err != Z_OK) {
 272     m_lasterror = wxSTREAM_WRITE_ERROR;
 273     wxString msg(m_deflate->msg, *wxConvCurrent);
 274     if (!msg)
 275       msg.Format(_("zlib error %d"), err);
 276     wxLogError(_("Can't write to deflate stream: %s\n"), msg.c_str());
 277   }
 278
 279   size -= m_deflate->avail_in;
 280   m_pos += size;
 281   return size;
 282 }
 283
 284 #endif
 285   // wxUSE_ZLIB && wxUSE_STREAMS
 286