src/common/zstream.cpp

   1 //////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/common/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
  23 #ifndef WX_PRECOMP
  24     #include "wx/intl.h"
  25     #include "wx/log.h"
  26     #include "wx/utils.h"
  27 #endif
  28
  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 compatibility 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       if (m_inflate->avail_out) {
 139         // Unread any data taken from past the end of the deflate stream, so that
 140         // any additional data can be read from the underlying stream (the crc
 141         // in a gzip for example)
 142         if (m_inflate->avail_in) {
 143           m_parent_i_stream->Reset();
 144           m_parent_i_stream->Ungetch(m_inflate->next_in, m_inflate->avail_in);
 145           m_inflate->avail_in = 0;
 146         }
 147         m_lasterror = wxSTREAM_EOF;
 148       }
 149       break;
 150
 151     case Z_BUF_ERROR:
 152       // Indicates that zlib was expecting more data, but the parent stream
 153       // has none. Other than Eof the error will have been already reported
 154       // by the parent strean,
 155       m_lasterror = wxSTREAM_READ_ERROR;
 156       if (m_parent_i_stream->Eof())
 157 #if WXWIN_COMPATIBILITY_2_4
 158         if (m_24compatibilty)
 159           m_lasterror = wxSTREAM_EOF;
 160         else
 161 #endif
 162           wxLogError(_("Can't read inflate stream: unexpected EOF in underlying stream."));
 163       break;
 164
 165     default:
 166       wxString msg(m_inflate->msg, *wxConvCurrent);
 167       if (!msg)
 168         msg = wxString::Format(_("zlib error %d"), err);
 169       wxLogError(_("Can't read from inflate stream: %s"), msg.c_str());
 170       m_lasterror = wxSTREAM_READ_ERROR;
 171   }
 172
 173   size -= m_inflate->avail_out;
 174   m_pos += size;
 175   return size;
 176 }
 177
 178 /* static */ bool wxZlibInputStream::CanHandleGZip()
 179 {
 180   const char *dot = strchr(zlibVersion(), '.');
 181   int major = atoi(zlibVersion());
 182   int minor = dot ? atoi(dot + 1) : 0;
 183   return major > 1 || (major == 1 && minor >= 2);
 184 }
 185
 186
 187 //////////////////////
 188 // wxZlibOutputStream
 189 //////////////////////
 190
 191 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream,
 192                                        int level,
 193                                        int flags)
 194  : wxFilterOutputStream(stream)
 195 {
 196   m_deflate = NULL;
 197   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 198   m_z_size = ZSTREAM_BUFFER_SIZE;
 199   m_pos = 0;
 200
 201   if ( level == -1 )
 202   {
 203     level = Z_DEFAULT_COMPRESSION;
 204   }
 205   else
 206   {
 207     wxASSERT_MSG(level >= 0 && level <= 9, wxT("wxZlibOutputStream compression level must be between 0 and 9!"));
 208   }
 209
 210   // if gzip is asked for but not supported...
 211   if (flags == wxZLIB_GZIP && !CanHandleGZip()) {
 212     wxLogError(_("Gzip not supported by this version of zlib"));
 213     m_lasterror = wxSTREAM_WRITE_ERROR;
 214     return;
 215   }
 216
 217   if (m_z_buffer) {
 218     m_deflate = new z_stream_s;
 219
 220     if (m_deflate) {
 221       memset(m_deflate, 0, sizeof(z_stream_s));
 222       m_deflate->next_out = m_z_buffer;
 223       m_deflate->avail_out = m_z_size;
 224
 225       // see zlib.h for documentation on windowBits
 226       int windowBits = MAX_WBITS;
 227       switch (flags) {
 228         case wxZLIB_NO_HEADER:  windowBits = -MAX_WBITS; break;
 229         case wxZLIB_ZLIB:       windowBits = MAX_WBITS; break;
 230         case wxZLIB_GZIP:       windowBits = MAX_WBITS | ZSTREAM_GZIP; break;
 231         default:                wxFAIL_MSG(wxT("Invalid zlib flag"));
 232       }
 233
 234       if (deflateInit2(m_deflate, level, Z_DEFLATED, windowBits,
 235                        8, Z_DEFAULT_STRATEGY) == Z_OK)
 236         return;
 237     }
 238   }
 239
 240   wxLogError(_("Can't initialize zlib deflate stream."));
 241   m_lasterror = wxSTREAM_WRITE_ERROR;
 242 }
 243
 244 bool wxZlibOutputStream::Close()
 245  {
 246   DoFlush(true);
 247    deflateEnd(m_deflate);
 248    delete m_deflate;
 249
 250   m_deflate = NULL;
 251    delete[] m_z_buffer;
 252   m_z_buffer = NULL;
 253   return IsOk();
 254  }
 255
 256 void wxZlibOutputStream::DoFlush(bool final)
 257 {
 258   if (!m_deflate || !m_z_buffer)
 259     m_lasterror = wxSTREAM_WRITE_ERROR;
 260   if (!IsOk())
 261     return;
 262
 263   int err = Z_OK;
 264   bool done = false;
 265
 266   while (err == Z_OK || err == Z_STREAM_END) {
 267     size_t len = m_z_size  - m_deflate->avail_out;
 268     if (len) {
 269       if (m_parent_o_stream->Write(m_z_buffer, len).LastWrite() != len) {
 270         m_lasterror = wxSTREAM_WRITE_ERROR;
 271         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 272         break;
 273       }
 274       m_deflate->next_out = m_z_buffer;
 275       m_deflate->avail_out = m_z_size;
 276     }
 277
 278     if (done)
 279       break;
 280     err = deflate(m_deflate, final ? Z_FINISH : Z_FULL_FLUSH);
 281     done = m_deflate->avail_out != 0 || err == Z_STREAM_END;
 282   }
 283 }
 284
 285 size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size)
 286 {
 287   wxASSERT_MSG(m_deflate && m_z_buffer, wxT("Deflate stream not open"));
 288
 289   if (!m_deflate || !m_z_buffer)
 290   {
 291     // notice that this will make IsOk() test just below return false
 292     m_lasterror = wxSTREAM_WRITE_ERROR;
 293   }
 294
 295   if (!IsOk() || !size)
 296     return 0;
 297
 298   int err = Z_OK;
 299   m_deflate->next_in = (unsigned char *)buffer;
 300   m_deflate->avail_in = size;
 301
 302   while (err == Z_OK && m_deflate->avail_in > 0) {
 303     if (m_deflate->avail_out == 0) {
 304       m_parent_o_stream->Write(m_z_buffer, m_z_size);
 305       if (m_parent_o_stream->LastWrite() != m_z_size) {
 306         m_lasterror = wxSTREAM_WRITE_ERROR;
 307         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 308         break;
 309       }
 310
 311       m_deflate->next_out = m_z_buffer;
 312       m_deflate->avail_out = m_z_size;
 313     }
 314
 315     err = deflate(m_deflate, Z_NO_FLUSH);
 316   }
 317
 318   if (err != Z_OK) {
 319     m_lasterror = wxSTREAM_WRITE_ERROR;
 320     wxString msg(m_deflate->msg, *wxConvCurrent);
 321     if (!msg)
 322       msg = wxString::Format(_("zlib error %d"), err);
 323     wxLogError(_("Can't write to deflate stream: %s"), msg.c_str());
 324   }
 325
 326   size -= m_deflate->avail_in;
 327   m_pos += size;
 328   return size;
 329 }
 330
 331 /* static */ bool wxZlibOutputStream::CanHandleGZip()
 332 {
 333   return wxZlibInputStream::CanHandleGZip();
 334 }
 335
 336 #endif
 337   // wxUSE_ZLIB && wxUSE_STREAMS