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     ZSTREAM_GZIP        = 0x10,     // gzip header
  43     ZSTREAM_AUTO        = 0x20      // auto detect between gzip and zlib
  44 };
  45
  46 //////////////////////
  47 // wxZlibInputStream
  48 //////////////////////
  49
  50 wxZlibInputStream::wxZlibInputStream(wxInputStream& stream, int flags)
  51   : wxFilterInputStream(stream)
  52 {
  53   m_inflate = NULL;
  54   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
  55   m_z_size = ZSTREAM_BUFFER_SIZE;
  56   m_pos = 0;
  57
  58 #if WXWIN_COMPATIBILITY_2_4
  59   // treat compatibilty mode as auto
  60   m_24compatibilty = flags == wxZLIB_24COMPATIBLE;
  61   if (m_24compatibilty)
  62     flags = wxZLIB_AUTO;
  63 #endif
  64
  65   // if gzip is asked for but not supported...
  66   if ((flags == wxZLIB_GZIP || flags == wxZLIB_AUTO) && !CanHandleGZip()) {
  67     if (flags == wxZLIB_AUTO) {
  68       // an error will come later if the input turns out not to be a zlib
  69       flags = wxZLIB_ZLIB;
  70     }
  71     else {
  72       wxLogError(_("Gzip not supported by this version of zlib"));
  73       m_lasterror = wxSTREAM_READ_ERROR;
  74       return;
  75     }
  76   }
  77
  78   if (m_z_buffer) {
  79     m_inflate = new z_stream_s;
  80
  81     if (m_inflate) {
  82       memset(m_inflate, 0, sizeof(z_stream_s));
  83
  84       // see zlib.h for documentation on windowBits
  85       int windowBits = MAX_WBITS;
  86       switch (flags) {
  87         case wxZLIB_NO_HEADER:  windowBits = -MAX_WBITS; break;
  88         case wxZLIB_ZLIB:       windowBits = MAX_WBITS; break;
  89         case wxZLIB_GZIP:       windowBits = MAX_WBITS | ZSTREAM_GZIP; break;
  90         case wxZLIB_AUTO:       windowBits = MAX_WBITS | ZSTREAM_AUTO; break;
  91         default:                wxFAIL_MSG(wxT("Invalid zlib flag"));
  92       }
  93
  94       if (inflateInit2(m_inflate, windowBits) == Z_OK)
  95         return;
  96     }
  97   }
  98
  99   wxLogError(_("Can't initialize zlib inflate stream."));
 100   m_lasterror = wxSTREAM_READ_ERROR;
 101 }
 102
 103 wxZlibInputStream::~wxZlibInputStream()
 104 {
 105   inflateEnd(m_inflate);
 106   delete m_inflate;
 107
 108   delete [] m_z_buffer;
 109 }
 110
 111 size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size)
 112 {
 113   wxASSERT_MSG(m_inflate && m_z_buffer, wxT("Inflate stream not open"));
 114
 115   if (!m_inflate || !m_z_buffer)
 116     m_lasterror = wxSTREAM_READ_ERROR;
 117   if (!IsOk() || !size)
 118     return 0;
 119
 120   int err = Z_OK;
 121   m_inflate->next_out = (unsigned char *)buffer;
 122   m_inflate->avail_out = size;
 123
 124   while (err == Z_OK && m_inflate->avail_out > 0) {
 125     if (m_inflate->avail_in == 0 && m_parent_i_stream->IsOk()) {
 126       m_parent_i_stream->Read(m_z_buffer, m_z_size);
 127       m_inflate->next_in = m_z_buffer;
 128       m_inflate->avail_in = m_parent_i_stream->LastRead();
 129     }
 130     err = inflate(m_inflate, Z_SYNC_FLUSH);
 131   }
 132
 133   switch (err) {
 134     case Z_OK:
 135         break;
 136
 137     case Z_STREAM_END:
 138       // Unread any data taken from past the end of the deflate stream, so that
 139       // any additional data can be read from the underlying stream (the crc
 140       // in a gzip for example)
 141       if (m_inflate->avail_in) {
 142         m_parent_i_stream->Ungetch(m_inflate->next_in, m_inflate->avail_in);
 143         m_inflate->avail_in = 0;
 144       }
 145       m_lasterror = wxSTREAM_EOF;
 146       break;
 147
 148     case Z_BUF_ERROR:
 149       // Indicates that zlib was expecting more data, but the parent stream
 150       // has none. Other than Eof the error will have been already reported
 151       // by the parent strean,
 152       m_lasterror = wxSTREAM_READ_ERROR;
 153       if (m_parent_i_stream->Eof())
 154 #if WXWIN_COMPATIBILITY_2_4
 155         if (m_24compatibilty)
 156           m_lasterror = wxSTREAM_EOF;
 157         else
 158 #endif
 159           wxLogError(_("Can't read inflate stream: unexpected EOF in underlying stream."));
 160       break;
 161
 162     default:
 163       wxString msg(m_inflate->msg, *wxConvCurrent);
 164       if (!msg)
 165         msg.Format(_("zlib error %d"), err);
 166       wxLogError(_("Can't read from inflate stream: %s"), msg.c_str());
 167       m_lasterror = wxSTREAM_READ_ERROR;
 168   }
 169
 170   size -= m_inflate->avail_out;
 171   m_pos += size;
 172   return size;
 173 }
 174
 175 /* static */ bool wxZlibInputStream::CanHandleGZip()
 176 {
 177   const char *dot = strchr(zlibVersion(), '.');
 178   int major = atoi(zlibVersion());
 179   int minor = dot ? atoi(dot + 1) : 0;
 180   return major > 1 || (major == 1 && minor >= 2);
 181 }
 182
 183
 184 //////////////////////
 185 // wxZlibOutputStream
 186 //////////////////////
 187
 188 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream,
 189                                        int level,
 190                                        int flags)
 191  : wxFilterOutputStream(stream)
 192 {
 193   m_deflate = NULL;
 194   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 195   m_z_size = ZSTREAM_BUFFER_SIZE;
 196   m_pos = 0;
 197
 198   if ( level == -1 )
 199   {
 200     level = Z_DEFAULT_COMPRESSION;
 201   }
 202   else
 203   {
 204     wxASSERT_MSG(level >= 0 && level <= 9, wxT("wxZlibOutputStream compression level must be between 0 and 9!"));
 205   }
 206
 207   // if gzip is asked for but not supported...
 208   if (flags == wxZLIB_GZIP && !CanHandleGZip()) {
 209     wxLogError(_("Gzip not supported by this version of zlib"));
 210     m_lasterror = wxSTREAM_WRITE_ERROR;
 211     return;
 212   }
 213
 214   if (m_z_buffer) {
 215     m_deflate = new z_stream_s;
 216
 217     if (m_deflate) {
 218       memset(m_deflate, 0, sizeof(z_stream_s));
 219       m_deflate->next_out = m_z_buffer;
 220       m_deflate->avail_out = m_z_size;
 221
 222       // see zlib.h for documentation on windowBits
 223       int windowBits = MAX_WBITS;
 224       switch (flags) {
 225         case wxZLIB_NO_HEADER:  windowBits = -MAX_WBITS; break;
 226         case wxZLIB_ZLIB:       windowBits = MAX_WBITS; break;
 227         case wxZLIB_GZIP:       windowBits = MAX_WBITS | ZSTREAM_GZIP; break;
 228         default:                wxFAIL_MSG(wxT("Invalid zlib flag"));
 229       }
 230
 231       if (deflateInit2(m_deflate, level, Z_DEFLATED, windowBits,
 232                        8, Z_DEFAULT_STRATEGY) == Z_OK)
 233         return;
 234     }
 235   }
 236
 237   wxLogError(_("Can't initialize zlib deflate stream."));
 238   m_lasterror = wxSTREAM_WRITE_ERROR;
 239 }
 240
 241 bool wxZlibOutputStream::Close()
 242  {
 243   DoFlush(true);
 244    deflateEnd(m_deflate);
 245    delete m_deflate;
 246
 247   m_deflate = NULL;
 248    delete[] m_z_buffer;
 249   m_z_buffer = NULL;
 250   return IsOk();
 251  }
 252
 253 void wxZlibOutputStream::DoFlush(bool final)
 254 {
 255   if (!m_deflate || !m_z_buffer)
 256     m_lasterror = wxSTREAM_WRITE_ERROR;
 257   if (!IsOk())
 258     return;
 259
 260   int err = Z_OK;
 261   bool done = false;
 262
 263   while (err == Z_OK || err == Z_STREAM_END) {
 264     size_t len = m_z_size  - m_deflate->avail_out;
 265     if (len) {
 266       if (m_parent_o_stream->Write(m_z_buffer, len).LastWrite() != len) {
 267         m_lasterror = wxSTREAM_WRITE_ERROR;
 268         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 269         break;
 270       }
 271       m_deflate->next_out = m_z_buffer;
 272       m_deflate->avail_out = m_z_size;
 273     }
 274
 275     if (done)
 276       break;
 277     err = deflate(m_deflate, final ? Z_FINISH : Z_FULL_FLUSH);
 278     done = m_deflate->avail_out != 0 || err == Z_STREAM_END;
 279   }
 280 }
 281
 282 size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size)
 283 {
 284   wxASSERT_MSG(m_deflate && m_z_buffer, wxT("Deflate stream not open"));
 285
 286   if (!m_deflate || !m_z_buffer)
 287     m_lasterror = wxSTREAM_WRITE_ERROR;
 288   if (!IsOk() || !size)
 289     return 0;
 290
 291   int err = Z_OK;
 292   m_deflate->next_in = (unsigned char *)buffer;
 293   m_deflate->avail_in = size;
 294
 295   while (err == Z_OK && m_deflate->avail_in > 0) {
 296     if (m_deflate->avail_out == 0) {
 297       m_parent_o_stream->Write(m_z_buffer, m_z_size);
 298       if (m_parent_o_stream->LastWrite() != m_z_size) {
 299         m_lasterror = wxSTREAM_WRITE_ERROR;
 300         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 301         break;
 302       }
 303
 304       m_deflate->next_out = m_z_buffer;
 305       m_deflate->avail_out = m_z_size;
 306     }
 307
 308     err = deflate(m_deflate, Z_NO_FLUSH);
 309   }
 310
 311   if (err != Z_OK) {
 312     m_lasterror = wxSTREAM_WRITE_ERROR;
 313     wxString msg(m_deflate->msg, *wxConvCurrent);
 314     if (!msg)
 315       msg.Format(_("zlib error %d"), err);
 316     wxLogError(_("Can't write to deflate stream: %s"), msg.c_str());
 317   }
 318
 319   size -= m_deflate->avail_in;
 320   m_pos += size;
 321   return size;
 322 }
 323
 324 /* static */ bool wxZlibOutputStream::CanHandleGZip()
 325 {
 326   return wxZlibInputStream::CanHandleGZip();
 327 }
 328
 329 #endif
 330   // wxUSE_ZLIB && wxUSE_STREAMS
 331