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 /////////////////////////////////////////////////////////////////////////////
  48 // Zlib Class factory
  49
  50 IMPLEMENT_DYNAMIC_CLASS(wxZlibClassFactory, wxFilterClassFactory)
  51
  52 static wxZlibClassFactory g_wxZlibClassFactory;
  53
  54 wxZlibClassFactory::wxZlibClassFactory()
  55 {
  56     if (this == &g_wxZlibClassFactory)
  57         PushFront();
  58 }
  59
  60 const wxChar * const *
  61 wxZlibClassFactory::GetProtocols(wxStreamProtocolType type) const
  62 {
  63     static const wxChar *mimes[] = { _T("application/x-deflate"), NULL };
  64     static const wxChar *encs[] =  { _T("deflate"), NULL };
  65     static const wxChar *empty[] = { NULL };
  66
  67     switch (type) {
  68         case wxSTREAM_MIMETYPE:         return mimes;
  69         case wxSTREAM_ENCODING:         return encs;
  70         default:                        return empty;
  71     }
  72 }
  73
  74
  75 /////////////////////////////////////////////////////////////////////////////
  76 // Gzip Class factory
  77
  78 IMPLEMENT_DYNAMIC_CLASS(wxGzipClassFactory, wxFilterClassFactory)
  79
  80 static wxGzipClassFactory g_wxGzipClassFactory;
  81
  82 wxGzipClassFactory::wxGzipClassFactory()
  83 {
  84     if (this == &g_wxGzipClassFactory && wxZlibInputStream::CanHandleGZip())
  85         PushFront();
  86 }
  87
  88 const wxChar * const *
  89 wxGzipClassFactory::GetProtocols(wxStreamProtocolType type) const
  90 {
  91     static const wxChar *protos[] =
  92         { _T("gzip"), NULL };
  93     static const wxChar *mimes[] =
  94         { _T("application/gzip"), _T("application/x-gzip"), NULL };
  95     static const wxChar *encs[] =
  96         { _T("gzip"), NULL };
  97     static const wxChar *exts[] =
  98         { _T(".gz"), _T(".gzip"), NULL };
  99     static const wxChar *empty[] =
 100         { NULL };
 101
 102     switch (type) {
 103         case wxSTREAM_PROTOCOL:         return protos;
 104         case wxSTREAM_MIMETYPE:         return mimes;
 105         case wxSTREAM_ENCODING:         return encs;
 106         case wxSTREAM_FILEEXTENSION:    return exts;
 107         default:                        return empty;
 108     }
 109 }
 110
 111
 112 //////////////////////
 113 // wxZlibInputStream
 114 //////////////////////
 115
 116 wxZlibInputStream::wxZlibInputStream(wxInputStream& stream, int flags)
 117   : wxFilterInputStream(stream)
 118 {
 119     Init(flags);
 120 }
 121
 122 wxZlibInputStream::wxZlibInputStream(wxInputStream *stream, int flags)
 123   : wxFilterInputStream(stream)
 124 {
 125     Init(flags);
 126 }
 127
 128 void wxZlibInputStream::Init(int flags)
 129 {
 130   m_inflate = NULL;
 131   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 132   m_z_size = ZSTREAM_BUFFER_SIZE;
 133   m_pos = 0;
 134
 135 #if WXWIN_COMPATIBILITY_2_4
 136   // treat compatibility mode as auto
 137   m_24compatibilty = flags == wxZLIB_24COMPATIBLE;
 138   if (m_24compatibilty)
 139     flags = wxZLIB_AUTO;
 140 #endif
 141
 142   // if gzip is asked for but not supported...
 143   if ((flags == wxZLIB_GZIP || flags == wxZLIB_AUTO) && !CanHandleGZip()) {
 144     if (flags == wxZLIB_AUTO) {
 145       // an error will come later if the input turns out not to be a zlib
 146       flags = wxZLIB_ZLIB;
 147     }
 148     else {
 149       wxLogError(_("Gzip not supported by this version of zlib"));
 150       m_lasterror = wxSTREAM_READ_ERROR;
 151       return;
 152     }
 153   }
 154
 155   if (m_z_buffer) {
 156     m_inflate = new z_stream_s;
 157
 158     if (m_inflate) {
 159       memset(m_inflate, 0, sizeof(z_stream_s));
 160
 161       // see zlib.h for documentation on windowBits
 162       int windowBits = MAX_WBITS;
 163       switch (flags) {
 164         case wxZLIB_NO_HEADER:  windowBits = -MAX_WBITS; break;
 165         case wxZLIB_ZLIB:       windowBits = MAX_WBITS; break;
 166         case wxZLIB_GZIP:       windowBits = MAX_WBITS | ZSTREAM_GZIP; break;
 167         case wxZLIB_AUTO:       windowBits = MAX_WBITS | ZSTREAM_AUTO; break;
 168         default:                wxFAIL_MSG(wxT("Invalid zlib flag"));
 169       }
 170
 171       if (inflateInit2(m_inflate, windowBits) == Z_OK)
 172         return;
 173     }
 174   }
 175
 176   wxLogError(_("Can't initialize zlib inflate stream."));
 177   m_lasterror = wxSTREAM_READ_ERROR;
 178 }
 179
 180 wxZlibInputStream::~wxZlibInputStream()
 181 {
 182   inflateEnd(m_inflate);
 183   delete m_inflate;
 184
 185   delete [] m_z_buffer;
 186 }
 187
 188 size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size)
 189 {
 190   wxASSERT_MSG(m_inflate && m_z_buffer, wxT("Inflate stream not open"));
 191
 192   if (!m_inflate || !m_z_buffer)
 193     m_lasterror = wxSTREAM_READ_ERROR;
 194   if (!IsOk() || !size)
 195     return 0;
 196
 197   int err = Z_OK;
 198   m_inflate->next_out = (unsigned char *)buffer;
 199   m_inflate->avail_out = size;
 200
 201   while (err == Z_OK && m_inflate->avail_out > 0) {
 202     if (m_inflate->avail_in == 0 && m_parent_i_stream->IsOk()) {
 203       m_parent_i_stream->Read(m_z_buffer, m_z_size);
 204       m_inflate->next_in = m_z_buffer;
 205       m_inflate->avail_in = m_parent_i_stream->LastRead();
 206     }
 207     err = inflate(m_inflate, Z_SYNC_FLUSH);
 208   }
 209
 210   switch (err) {
 211     case Z_OK:
 212         break;
 213
 214     case Z_STREAM_END:
 215       if (m_inflate->avail_out) {
 216         // Unread any data taken from past the end of the deflate stream, so that
 217         // any additional data can be read from the underlying stream (the crc
 218         // in a gzip for example)
 219         if (m_inflate->avail_in) {
 220           m_parent_i_stream->Reset();
 221           m_parent_i_stream->Ungetch(m_inflate->next_in, m_inflate->avail_in);
 222           m_inflate->avail_in = 0;
 223         }
 224         m_lasterror = wxSTREAM_EOF;
 225       }
 226       break;
 227
 228     case Z_BUF_ERROR:
 229       // Indicates that zlib was expecting more data, but the parent stream
 230       // has none. Other than Eof the error will have been already reported
 231       // by the parent strean,
 232       m_lasterror = wxSTREAM_READ_ERROR;
 233       if (m_parent_i_stream->Eof())
 234 #if WXWIN_COMPATIBILITY_2_4
 235         if (m_24compatibilty)
 236           m_lasterror = wxSTREAM_EOF;
 237         else
 238 #endif
 239           wxLogError(_("Can't read inflate stream: unexpected EOF in underlying stream."));
 240       break;
 241
 242     default:
 243       wxString msg(m_inflate->msg, *wxConvCurrent);
 244       if (!msg)
 245         msg = wxString::Format(_("zlib error %d"), err);
 246       wxLogError(_("Can't read from inflate stream: %s"), msg.c_str());
 247       m_lasterror = wxSTREAM_READ_ERROR;
 248   }
 249
 250   size -= m_inflate->avail_out;
 251   m_pos += size;
 252   return size;
 253 }
 254
 255 /* static */ bool wxZlibInputStream::CanHandleGZip()
 256 {
 257   const char *dot = strchr(zlibVersion(), '.');
 258   int major = atoi(zlibVersion());
 259   int minor = dot ? atoi(dot + 1) : 0;
 260   return major > 1 || (major == 1 && minor >= 2);
 261 }
 262
 263
 264 //////////////////////
 265 // wxZlibOutputStream
 266 //////////////////////
 267
 268 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream,
 269                                        int level,
 270                                        int flags)
 271  : wxFilterOutputStream(stream)
 272 {
 273     Init(level, flags);
 274 }
 275
 276 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream *stream,
 277                                        int level,
 278                                        int flags)
 279  : wxFilterOutputStream(stream)
 280 {
 281     Init(level, flags);
 282 }
 283
 284 void wxZlibOutputStream::Init(int level, int flags)
 285 {
 286   m_deflate = NULL;
 287   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 288   m_z_size = ZSTREAM_BUFFER_SIZE;
 289   m_pos = 0;
 290
 291   if ( level == -1 )
 292   {
 293     level = Z_DEFAULT_COMPRESSION;
 294   }
 295   else
 296   {
 297     wxASSERT_MSG(level >= 0 && level <= 9, wxT("wxZlibOutputStream compression level must be between 0 and 9!"));
 298   }
 299
 300   // if gzip is asked for but not supported...
 301   if (flags == wxZLIB_GZIP && !CanHandleGZip()) {
 302     wxLogError(_("Gzip not supported by this version of zlib"));
 303     m_lasterror = wxSTREAM_WRITE_ERROR;
 304     return;
 305   }
 306
 307   if (m_z_buffer) {
 308     m_deflate = new z_stream_s;
 309
 310     if (m_deflate) {
 311       memset(m_deflate, 0, sizeof(z_stream_s));
 312       m_deflate->next_out = m_z_buffer;
 313       m_deflate->avail_out = m_z_size;
 314
 315       // see zlib.h for documentation on windowBits
 316       int windowBits = MAX_WBITS;
 317       switch (flags) {
 318         case wxZLIB_NO_HEADER:  windowBits = -MAX_WBITS; break;
 319         case wxZLIB_ZLIB:       windowBits = MAX_WBITS; break;
 320         case wxZLIB_GZIP:       windowBits = MAX_WBITS | ZSTREAM_GZIP; break;
 321         default:                wxFAIL_MSG(wxT("Invalid zlib flag"));
 322       }
 323
 324       if (deflateInit2(m_deflate, level, Z_DEFLATED, windowBits,
 325                        8, Z_DEFAULT_STRATEGY) == Z_OK)
 326         return;
 327     }
 328   }
 329
 330   wxLogError(_("Can't initialize zlib deflate stream."));
 331   m_lasterror = wxSTREAM_WRITE_ERROR;
 332 }
 333
 334 bool wxZlibOutputStream::Close()
 335  {
 336   DoFlush(true);
 337    deflateEnd(m_deflate);
 338    delete m_deflate;
 339
 340   m_deflate = NULL;
 341    delete[] m_z_buffer;
 342   m_z_buffer = NULL;
 343
 344   return wxFilterOutputStream::Close() && IsOk();
 345  }
 346
 347 void wxZlibOutputStream::DoFlush(bool final)
 348 {
 349   if (!m_deflate || !m_z_buffer)
 350     m_lasterror = wxSTREAM_WRITE_ERROR;
 351   if (!IsOk())
 352     return;
 353
 354   int err = Z_OK;
 355   bool done = false;
 356
 357   while (err == Z_OK || err == Z_STREAM_END) {
 358     size_t len = m_z_size  - m_deflate->avail_out;
 359     if (len) {
 360       if (m_parent_o_stream->Write(m_z_buffer, len).LastWrite() != len) {
 361         m_lasterror = wxSTREAM_WRITE_ERROR;
 362         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 363         break;
 364       }
 365       m_deflate->next_out = m_z_buffer;
 366       m_deflate->avail_out = m_z_size;
 367     }
 368
 369     if (done)
 370       break;
 371     err = deflate(m_deflate, final ? Z_FINISH : Z_FULL_FLUSH);
 372     done = m_deflate->avail_out != 0 || err == Z_STREAM_END;
 373   }
 374 }
 375
 376 size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size)
 377 {
 378   wxASSERT_MSG(m_deflate && m_z_buffer, wxT("Deflate stream not open"));
 379
 380   if (!m_deflate || !m_z_buffer)
 381   {
 382     // notice that this will make IsOk() test just below return false
 383     m_lasterror = wxSTREAM_WRITE_ERROR;
 384   }
 385
 386   if (!IsOk() || !size)
 387     return 0;
 388
 389   int err = Z_OK;
 390   m_deflate->next_in = (unsigned char *)buffer;
 391   m_deflate->avail_in = size;
 392
 393   while (err == Z_OK && m_deflate->avail_in > 0) {
 394     if (m_deflate->avail_out == 0) {
 395       m_parent_o_stream->Write(m_z_buffer, m_z_size);
 396       if (m_parent_o_stream->LastWrite() != m_z_size) {
 397         m_lasterror = wxSTREAM_WRITE_ERROR;
 398         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 399         break;
 400       }
 401
 402       m_deflate->next_out = m_z_buffer;
 403       m_deflate->avail_out = m_z_size;
 404     }
 405
 406     err = deflate(m_deflate, Z_NO_FLUSH);
 407   }
 408
 409   if (err != Z_OK) {
 410     m_lasterror = wxSTREAM_WRITE_ERROR;
 411     wxString msg(m_deflate->msg, *wxConvCurrent);
 412     if (!msg)
 413       msg = wxString::Format(_("zlib error %d"), err);
 414     wxLogError(_("Can't write to deflate stream: %s"), msg.c_str());
 415   }
 416
 417   size -= m_deflate->avail_in;
 418   m_pos += size;
 419   return size;
 420 }
 421
 422 /* static */ bool wxZlibOutputStream::CanHandleGZip()
 423 {
 424   return wxZlibInputStream::CanHandleGZip();
 425 }
 426
 427 #endif
 428   // wxUSE_ZLIB && wxUSE_STREAMS