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_FILEEXT:  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 gzip is asked for but not supported...
 136   if ((flags == wxZLIB_GZIP || flags == wxZLIB_AUTO) && !CanHandleGZip()) {
 137     if (flags == wxZLIB_AUTO) {
 138       // an error will come later if the input turns out not to be a zlib
 139       flags = wxZLIB_ZLIB;
 140     }
 141     else {
 142       wxLogError(_("Gzip not supported by this version of zlib"));
 143       m_lasterror = wxSTREAM_READ_ERROR;
 144       return;
 145     }
 146   }
 147
 148   if (m_z_buffer) {
 149     m_inflate = new z_stream_s;
 150
 151     if (m_inflate) {
 152       memset(m_inflate, 0, sizeof(z_stream_s));
 153
 154       // see zlib.h for documentation on windowBits
 155       int windowBits = MAX_WBITS;
 156       switch (flags) {
 157         case wxZLIB_NO_HEADER:  windowBits = -MAX_WBITS; break;
 158         case wxZLIB_ZLIB:       windowBits = MAX_WBITS; break;
 159         case wxZLIB_GZIP:       windowBits = MAX_WBITS | ZSTREAM_GZIP; break;
 160         case wxZLIB_AUTO:       windowBits = MAX_WBITS | ZSTREAM_AUTO; break;
 161         default:                wxFAIL_MSG(wxT("Invalid zlib flag"));
 162       }
 163
 164       if (inflateInit2(m_inflate, windowBits) == Z_OK)
 165         return;
 166     }
 167   }
 168
 169   wxLogError(_("Can't initialize zlib inflate stream."));
 170   m_lasterror = wxSTREAM_READ_ERROR;
 171 }
 172
 173 wxZlibInputStream::~wxZlibInputStream()
 174 {
 175   inflateEnd(m_inflate);
 176   delete m_inflate;
 177
 178   delete [] m_z_buffer;
 179 }
 180
 181 size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size)
 182 {
 183   wxASSERT_MSG(m_inflate && m_z_buffer, wxT("Inflate stream not open"));
 184
 185   if (!m_inflate || !m_z_buffer)
 186     m_lasterror = wxSTREAM_READ_ERROR;
 187   if (!IsOk() || !size)
 188     return 0;
 189
 190   int err = Z_OK;
 191   m_inflate->next_out = (unsigned char *)buffer;
 192   m_inflate->avail_out = size;
 193
 194   while (err == Z_OK && m_inflate->avail_out > 0) {
 195     if (m_inflate->avail_in == 0 && m_parent_i_stream->IsOk()) {
 196       m_parent_i_stream->Read(m_z_buffer, m_z_size);
 197       m_inflate->next_in = m_z_buffer;
 198       m_inflate->avail_in = m_parent_i_stream->LastRead();
 199     }
 200     err = inflate(m_inflate, Z_SYNC_FLUSH);
 201   }
 202
 203   switch (err) {
 204     case Z_OK:
 205         break;
 206
 207     case Z_STREAM_END:
 208       if (m_inflate->avail_out) {
 209         // Unread any data taken from past the end of the deflate stream, so that
 210         // any additional data can be read from the underlying stream (the crc
 211         // in a gzip for example)
 212         if (m_inflate->avail_in) {
 213           m_parent_i_stream->Reset();
 214           m_parent_i_stream->Ungetch(m_inflate->next_in, m_inflate->avail_in);
 215           m_inflate->avail_in = 0;
 216         }
 217         m_lasterror = wxSTREAM_EOF;
 218       }
 219       break;
 220
 221     case Z_BUF_ERROR:
 222       // Indicates that zlib was expecting more data, but the parent stream
 223       // has none. Other than Eof the error will have been already reported
 224       // by the parent strean,
 225       m_lasterror = wxSTREAM_READ_ERROR;
 226       if (m_parent_i_stream->Eof())
 227           wxLogError(_("Can't read inflate stream: unexpected EOF in underlying stream."));
 228       break;
 229
 230     default:
 231       wxString msg(m_inflate->msg, *wxConvCurrent);
 232       if (!msg)
 233         msg = wxString::Format(_("zlib error %d"), err);
 234       wxLogError(_("Can't read from inflate stream: %s"), msg.c_str());
 235       m_lasterror = wxSTREAM_READ_ERROR;
 236   }
 237
 238   size -= m_inflate->avail_out;
 239   m_pos += size;
 240   return size;
 241 }
 242
 243 /* static */ bool wxZlibInputStream::CanHandleGZip()
 244 {
 245   const char *dot = strchr(zlibVersion(), '.');
 246   int major = atoi(zlibVersion());
 247   int minor = dot ? atoi(dot + 1) : 0;
 248   return major > 1 || (major == 1 && minor >= 2);
 249 }
 250
 251
 252 //////////////////////
 253 // wxZlibOutputStream
 254 //////////////////////
 255
 256 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream,
 257                                        int level,
 258                                        int flags)
 259  : wxFilterOutputStream(stream)
 260 {
 261     Init(level, flags);
 262 }
 263
 264 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream *stream,
 265                                        int level,
 266                                        int flags)
 267  : wxFilterOutputStream(stream)
 268 {
 269     Init(level, flags);
 270 }
 271
 272 void wxZlibOutputStream::Init(int level, int flags)
 273 {
 274   m_deflate = NULL;
 275   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 276   m_z_size = ZSTREAM_BUFFER_SIZE;
 277   m_pos = 0;
 278
 279   if ( level == -1 )
 280   {
 281     level = Z_DEFAULT_COMPRESSION;
 282   }
 283   else
 284   {
 285     wxASSERT_MSG(level >= 0 && level <= 9, wxT("wxZlibOutputStream compression level must be between 0 and 9!"));
 286   }
 287
 288   // if gzip is asked for but not supported...
 289   if (flags == wxZLIB_GZIP && !CanHandleGZip()) {
 290     wxLogError(_("Gzip not supported by this version of zlib"));
 291     m_lasterror = wxSTREAM_WRITE_ERROR;
 292     return;
 293   }
 294
 295   if (m_z_buffer) {
 296     m_deflate = new z_stream_s;
 297
 298     if (m_deflate) {
 299       memset(m_deflate, 0, sizeof(z_stream_s));
 300       m_deflate->next_out = m_z_buffer;
 301       m_deflate->avail_out = m_z_size;
 302
 303       // see zlib.h for documentation on windowBits
 304       int windowBits = MAX_WBITS;
 305       switch (flags) {
 306         case wxZLIB_NO_HEADER:  windowBits = -MAX_WBITS; break;
 307         case wxZLIB_ZLIB:       windowBits = MAX_WBITS; break;
 308         case wxZLIB_GZIP:       windowBits = MAX_WBITS | ZSTREAM_GZIP; break;
 309         default:                wxFAIL_MSG(wxT("Invalid zlib flag"));
 310       }
 311
 312       if (deflateInit2(m_deflate, level, Z_DEFLATED, windowBits,
 313                        8, Z_DEFAULT_STRATEGY) == Z_OK)
 314         return;
 315     }
 316   }
 317
 318   wxLogError(_("Can't initialize zlib deflate stream."));
 319   m_lasterror = wxSTREAM_WRITE_ERROR;
 320 }
 321
 322 bool wxZlibOutputStream::Close()
 323  {
 324   DoFlush(true);
 325    deflateEnd(m_deflate);
 326    delete m_deflate;
 327
 328   m_deflate = NULL;
 329    delete[] m_z_buffer;
 330   m_z_buffer = NULL;
 331
 332   return wxFilterOutputStream::Close() && IsOk();
 333  }
 334
 335 void wxZlibOutputStream::DoFlush(bool final)
 336 {
 337   if (!m_deflate || !m_z_buffer)
 338     m_lasterror = wxSTREAM_WRITE_ERROR;
 339   if (!IsOk())
 340     return;
 341
 342   int err = Z_OK;
 343   bool done = false;
 344
 345   while (err == Z_OK || err == Z_STREAM_END) {
 346     size_t len = m_z_size  - m_deflate->avail_out;
 347     if (len) {
 348       if (m_parent_o_stream->Write(m_z_buffer, len).LastWrite() != len) {
 349         m_lasterror = wxSTREAM_WRITE_ERROR;
 350         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 351         break;
 352       }
 353       m_deflate->next_out = m_z_buffer;
 354       m_deflate->avail_out = m_z_size;
 355     }
 356
 357     if (done)
 358       break;
 359     err = deflate(m_deflate, final ? Z_FINISH : Z_FULL_FLUSH);
 360     done = m_deflate->avail_out != 0 || err == Z_STREAM_END;
 361   }
 362 }
 363
 364 size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size)
 365 {
 366   wxASSERT_MSG(m_deflate && m_z_buffer, wxT("Deflate stream not open"));
 367
 368   if (!m_deflate || !m_z_buffer)
 369   {
 370     // notice that this will make IsOk() test just below return false
 371     m_lasterror = wxSTREAM_WRITE_ERROR;
 372   }
 373
 374   if (!IsOk() || !size)
 375     return 0;
 376
 377   int err = Z_OK;
 378   m_deflate->next_in = (unsigned char *)buffer;
 379   m_deflate->avail_in = size;
 380
 381   while (err == Z_OK && m_deflate->avail_in > 0) {
 382     if (m_deflate->avail_out == 0) {
 383       m_parent_o_stream->Write(m_z_buffer, m_z_size);
 384       if (m_parent_o_stream->LastWrite() != m_z_size) {
 385         m_lasterror = wxSTREAM_WRITE_ERROR;
 386         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 387         break;
 388       }
 389
 390       m_deflate->next_out = m_z_buffer;
 391       m_deflate->avail_out = m_z_size;
 392     }
 393
 394     err = deflate(m_deflate, Z_NO_FLUSH);
 395   }
 396
 397   if (err != Z_OK) {
 398     m_lasterror = wxSTREAM_WRITE_ERROR;
 399     wxString msg(m_deflate->msg, *wxConvCurrent);
 400     if (!msg)
 401       msg = wxString::Format(_("zlib error %d"), err);
 402     wxLogError(_("Can't write to deflate stream: %s"), msg.c_str());
 403   }
 404
 405   size -= m_deflate->avail_in;
 406   m_pos += size;
 407   return size;
 408 }
 409
 410 /* static */ bool wxZlibOutputStream::CanHandleGZip()
 411 {
 412   return wxZlibInputStream::CanHandleGZip();
 413 }
 414
 415 #endif
 416   // wxUSE_ZLIB && wxUSE_STREAMS