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 // For compilers that support precompilation, includes "wx.h".
  13 #include "wx/wxprec.h"
  14
  15 #ifdef __BORLANDC__
  16   #pragma hdrstop
  17 #endif
  18
  19 #if wxUSE_ZLIB && wxUSE_STREAMS
  20
  21 #include "wx/zstream.h"
  22 #include "wx/utils.h"
  23 #include "wx/intl.h"
  24 #include "wx/log.h"
  25
  26 // normally, the compiler options should contain -I../zlib, but it is
  27 // apparently not the case for all MSW makefiles and so, unless we use
  28 // configure (which defines __WX_SETUP_H__) or it is explicitly overridden by
  29 // the user (who can define wxUSE_ZLIB_H_IN_PATH), we hardcode the path here
  30 #if defined(__WXMSW__) && !defined(__WX_SETUP_H__) && !defined(wxUSE_ZLIB_H_IN_PATH)
  31    #include "../zlib/zlib.h"
  32 #else
  33    #include "zlib.h"
  34 #endif
  35
  36 enum {
  37     ZSTREAM_BUFFER_SIZE = 16384,
  38     ZSTREAM_GZIP        = 0x10,     // gzip header
  39     ZSTREAM_AUTO        = 0x20      // auto detect between gzip and zlib
  40 };
  41
  42 //////////////////////
  43 // wxZlibInputStream
  44 //////////////////////
  45
  46 wxZlibInputStream::wxZlibInputStream(wxInputStream& stream, int flags)
  47   : wxFilterInputStream(stream)
  48 {
  49   m_inflate = NULL;
  50   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
  51   m_z_size = ZSTREAM_BUFFER_SIZE;
  52   m_pos = 0;
  53
  54 #if WXWIN_COMPATIBILITY_2_4
  55   // treat compatibility mode as auto
  56   m_24compatibilty = flags == wxZLIB_24COMPATIBLE;
  57   if (m_24compatibilty)
  58     flags = wxZLIB_AUTO;
  59 #endif
  60
  61   // if gzip is asked for but not supported...
  62   if ((flags == wxZLIB_GZIP || flags == wxZLIB_AUTO) && !CanHandleGZip()) {
  63     if (flags == wxZLIB_AUTO) {
  64       // an error will come later if the input turns out not to be a zlib
  65       flags = wxZLIB_ZLIB;
  66     }
  67     else {
  68       wxLogError(_("Gzip not supported by this version of zlib"));
  69       m_lasterror = wxSTREAM_READ_ERROR;
  70       return;
  71     }
  72   }
  73
  74   if (m_z_buffer) {
  75     m_inflate = new z_stream_s;
  76
  77     if (m_inflate) {
  78       memset(m_inflate, 0, sizeof(z_stream_s));
  79
  80       // see zlib.h for documentation on windowBits
  81       int windowBits = MAX_WBITS;
  82       switch (flags) {
  83         case wxZLIB_NO_HEADER:  windowBits = -MAX_WBITS; break;
  84         case wxZLIB_ZLIB:       windowBits = MAX_WBITS; break;
  85         case wxZLIB_GZIP:       windowBits = MAX_WBITS | ZSTREAM_GZIP; break;
  86         case wxZLIB_AUTO:       windowBits = MAX_WBITS | ZSTREAM_AUTO; break;
  87         default:                wxFAIL_MSG(wxT("Invalid zlib flag"));
  88       }
  89
  90       if (inflateInit2(m_inflate, windowBits) == Z_OK)
  91         return;
  92     }
  93   }
  94
  95   wxLogError(_("Can't initialize zlib inflate stream."));
  96   m_lasterror = wxSTREAM_READ_ERROR;
  97 }
  98
  99 wxZlibInputStream::~wxZlibInputStream()
 100 {
 101   inflateEnd(m_inflate);
 102   delete m_inflate;
 103
 104   delete [] m_z_buffer;
 105 }
 106
 107 size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size)
 108 {
 109   wxASSERT_MSG(m_inflate && m_z_buffer, wxT("Inflate stream not open"));
 110
 111   if (!m_inflate || !m_z_buffer)
 112     m_lasterror = wxSTREAM_READ_ERROR;
 113   if (!IsOk() || !size)
 114     return 0;
 115
 116   int err = Z_OK;
 117   m_inflate->next_out = (unsigned char *)buffer;
 118   m_inflate->avail_out = size;
 119
 120   while (err == Z_OK && m_inflate->avail_out > 0) {
 121     if (m_inflate->avail_in == 0 && m_parent_i_stream->IsOk()) {
 122       m_parent_i_stream->Read(m_z_buffer, m_z_size);
 123       m_inflate->next_in = m_z_buffer;
 124       m_inflate->avail_in = m_parent_i_stream->LastRead();
 125     }
 126     err = inflate(m_inflate, Z_SYNC_FLUSH);
 127   }
 128
 129   switch (err) {
 130     case Z_OK:
 131         break;
 132
 133     case Z_STREAM_END:
 134       if (m_inflate->avail_out) {
 135         // Unread any data taken from past the end of the deflate stream, so that
 136         // any additional data can be read from the underlying stream (the crc
 137         // in a gzip for example)
 138         if (m_inflate->avail_in) {
 139           m_parent_i_stream->Ungetch(m_inflate->next_in, m_inflate->avail_in);
 140           m_inflate->avail_in = 0;
 141         }
 142         m_lasterror = wxSTREAM_EOF;
 143       }
 144       break;
 145
 146     case Z_BUF_ERROR:
 147       // Indicates that zlib was expecting more data, but the parent stream
 148       // has none. Other than Eof the error will have been already reported
 149       // by the parent strean,
 150       m_lasterror = wxSTREAM_READ_ERROR;
 151       if (m_parent_i_stream->Eof())
 152 #if WXWIN_COMPATIBILITY_2_4
 153         if (m_24compatibilty)
 154           m_lasterror = wxSTREAM_EOF;
 155         else
 156 #endif
 157           wxLogError(_("Can't read inflate stream: unexpected EOF in underlying stream."));
 158       break;
 159
 160     default:
 161       wxString msg(m_inflate->msg, *wxConvCurrent);
 162       if (!msg)
 163         msg = wxString::Format(_("zlib error %d"), err);
 164       wxLogError(_("Can't read from inflate stream: %s"), msg.c_str());
 165       m_lasterror = wxSTREAM_READ_ERROR;
 166   }
 167
 168   size -= m_inflate->avail_out;
 169   m_pos += size;
 170   return size;
 171 }
 172
 173 /* static */ bool wxZlibInputStream::CanHandleGZip()
 174 {
 175   const char *dot = strchr(zlibVersion(), '.');
 176   int major = atoi(zlibVersion());
 177   int minor = dot ? atoi(dot + 1) : 0;
 178   return major > 1 || (major == 1 && minor >= 2);
 179 }
 180
 181
 182 //////////////////////
 183 // wxZlibOutputStream
 184 //////////////////////
 185
 186 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream,
 187                                        int level,
 188                                        int flags)
 189  : wxFilterOutputStream(stream)
 190 {
 191   m_deflate = NULL;
 192   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 193   m_z_size = ZSTREAM_BUFFER_SIZE;
 194   m_pos = 0;
 195
 196   if ( level == -1 )
 197   {
 198     level = Z_DEFAULT_COMPRESSION;
 199   }
 200   else
 201   {
 202     wxASSERT_MSG(level >= 0 && level <= 9, wxT("wxZlibOutputStream compression level must be between 0 and 9!"));
 203   }
 204
 205   // if gzip is asked for but not supported...
 206   if (flags == wxZLIB_GZIP && !CanHandleGZip()) {
 207     wxLogError(_("Gzip not supported by this version of zlib"));
 208     m_lasterror = wxSTREAM_WRITE_ERROR;
 209     return;
 210   }
 211
 212   if (m_z_buffer) {
 213     m_deflate = new z_stream_s;
 214
 215     if (m_deflate) {
 216       memset(m_deflate, 0, sizeof(z_stream_s));
 217       m_deflate->next_out = m_z_buffer;
 218       m_deflate->avail_out = m_z_size;
 219
 220       // see zlib.h for documentation on windowBits
 221       int windowBits = MAX_WBITS;
 222       switch (flags) {
 223         case wxZLIB_NO_HEADER:  windowBits = -MAX_WBITS; break;
 224         case wxZLIB_ZLIB:       windowBits = MAX_WBITS; break;
 225         case wxZLIB_GZIP:       windowBits = MAX_WBITS | ZSTREAM_GZIP; break;
 226         default:                wxFAIL_MSG(wxT("Invalid zlib flag"));
 227       }
 228
 229       if (deflateInit2(m_deflate, level, Z_DEFLATED, windowBits,
 230                        8, Z_DEFAULT_STRATEGY) == Z_OK)
 231         return;
 232     }
 233   }
 234
 235   wxLogError(_("Can't initialize zlib deflate stream."));
 236   m_lasterror = wxSTREAM_WRITE_ERROR;
 237 }
 238
 239 bool wxZlibOutputStream::Close()
 240  {
 241   DoFlush(true);
 242    deflateEnd(m_deflate);
 243    delete m_deflate;
 244
 245   m_deflate = NULL;
 246    delete[] m_z_buffer;
 247   m_z_buffer = NULL;
 248   return IsOk();
 249  }
 250
 251 void wxZlibOutputStream::DoFlush(bool final)
 252 {
 253   if (!m_deflate || !m_z_buffer)
 254     m_lasterror = wxSTREAM_WRITE_ERROR;
 255   if (!IsOk())
 256     return;
 257
 258   int err = Z_OK;
 259   bool done = false;
 260
 261   while (err == Z_OK || err == Z_STREAM_END) {
 262     size_t len = m_z_size  - m_deflate->avail_out;
 263     if (len) {
 264       if (m_parent_o_stream->Write(m_z_buffer, len).LastWrite() != len) {
 265         m_lasterror = wxSTREAM_WRITE_ERROR;
 266         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 267         break;
 268       }
 269       m_deflate->next_out = m_z_buffer;
 270       m_deflate->avail_out = m_z_size;
 271     }
 272
 273     if (done)
 274       break;
 275     err = deflate(m_deflate, final ? Z_FINISH : Z_FULL_FLUSH);
 276     done = m_deflate->avail_out != 0 || err == Z_STREAM_END;
 277   }
 278 }
 279
 280 size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size)
 281 {
 282   wxASSERT_MSG(m_deflate && m_z_buffer, wxT("Deflate stream not open"));
 283
 284   if (!m_deflate || !m_z_buffer)
 285     m_lasterror = wxSTREAM_WRITE_ERROR;
 286   if (!IsOk() || !size)
 287     return 0;
 288
 289   int err = Z_OK;
 290   m_deflate->next_in = (unsigned char *)buffer;
 291   m_deflate->avail_in = size;
 292
 293   while (err == Z_OK && m_deflate->avail_in > 0) {
 294     if (m_deflate->avail_out == 0) {
 295       m_parent_o_stream->Write(m_z_buffer, m_z_size);
 296       if (m_parent_o_stream->LastWrite() != m_z_size) {
 297         m_lasterror = wxSTREAM_WRITE_ERROR;
 298         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 299         break;
 300       }
 301
 302       m_deflate->next_out = m_z_buffer;
 303       m_deflate->avail_out = m_z_size;
 304     }
 305
 306     err = deflate(m_deflate, Z_NO_FLUSH);
 307   }
 308
 309   if (err != Z_OK) {
 310     m_lasterror = wxSTREAM_WRITE_ERROR;
 311     wxString msg(m_deflate->msg, *wxConvCurrent);
 312     if (!msg)
 313       msg = wxString::Format(_("zlib error %d"), err);
 314     wxLogError(_("Can't write to deflate stream: %s"), msg.c_str());
 315   }
 316
 317   size -= m_deflate->avail_in;
 318   m_pos += size;
 319   return size;
 320 }
 321
 322 /* static */ bool wxZlibOutputStream::CanHandleGZip()
 323 {
 324   return wxZlibInputStream::CanHandleGZip();
 325 }
 326
 327 #endif
 328   // wxUSE_ZLIB && wxUSE_STREAMS
 329