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 bool wxZlibInputStream::SetDictionary(const char *data, const size_t datalen)
 252 {
 253     return (inflateSetDictionary(m_inflate, (Bytef*)data, datalen) == Z_OK);
 254 }
 255
 256 bool wxZlibInputStream::SetDictionary(const wxMemoryBuffer &buf)
 257 {
 258     return SetDictionary((char*)buf.GetData(), buf.GetDataLen());
 259 }
 260
 261
 262 //////////////////////
 263 // wxZlibOutputStream
 264 //////////////////////
 265
 266 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream,
 267                                        int level,
 268                                        int flags)
 269  : wxFilterOutputStream(stream)
 270 {
 271     Init(level, flags);
 272 }
 273
 274 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream *stream,
 275                                        int level,
 276                                        int flags)
 277  : wxFilterOutputStream(stream)
 278 {
 279     Init(level, flags);
 280 }
 281
 282 void wxZlibOutputStream::Init(int level, int flags)
 283 {
 284   m_deflate = NULL;
 285   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 286   m_z_size = ZSTREAM_BUFFER_SIZE;
 287   m_pos = 0;
 288
 289   if ( level == -1 )
 290   {
 291     level = Z_DEFAULT_COMPRESSION;
 292   }
 293   else
 294   {
 295     wxASSERT_MSG(level >= 0 && level <= 9, wxT("wxZlibOutputStream compression level must be between 0 and 9!"));
 296   }
 297
 298   // if gzip is asked for but not supported...
 299   if (flags == wxZLIB_GZIP && !CanHandleGZip()) {
 300     wxLogError(_("Gzip not supported by this version of zlib"));
 301     m_lasterror = wxSTREAM_WRITE_ERROR;
 302     return;
 303   }
 304
 305   if (m_z_buffer) {
 306     m_deflate = new z_stream_s;
 307
 308     if (m_deflate) {
 309       memset(m_deflate, 0, sizeof(z_stream_s));
 310       m_deflate->next_out = m_z_buffer;
 311       m_deflate->avail_out = m_z_size;
 312
 313       // see zlib.h for documentation on windowBits
 314       int windowBits = MAX_WBITS;
 315       switch (flags) {
 316         case wxZLIB_NO_HEADER:  windowBits = -MAX_WBITS; break;
 317         case wxZLIB_ZLIB:       windowBits = MAX_WBITS; break;
 318         case wxZLIB_GZIP:       windowBits = MAX_WBITS | ZSTREAM_GZIP; break;
 319         default:                wxFAIL_MSG(wxT("Invalid zlib flag"));
 320       }
 321
 322       if (deflateInit2(m_deflate, level, Z_DEFLATED, windowBits,
 323                        8, Z_DEFAULT_STRATEGY) == Z_OK)
 324         return;
 325     }
 326   }
 327
 328   wxLogError(_("Can't initialize zlib deflate stream."));
 329   m_lasterror = wxSTREAM_WRITE_ERROR;
 330 }
 331
 332 bool wxZlibOutputStream::Close()
 333  {
 334   DoFlush(true);
 335    deflateEnd(m_deflate);
 336    delete m_deflate;
 337
 338   m_deflate = NULL;
 339    delete[] m_z_buffer;
 340   m_z_buffer = NULL;
 341
 342   return wxFilterOutputStream::Close() && IsOk();
 343  }
 344
 345 void wxZlibOutputStream::DoFlush(bool final)
 346 {
 347   if (!m_deflate || !m_z_buffer)
 348     m_lasterror = wxSTREAM_WRITE_ERROR;
 349   if (!IsOk())
 350     return;
 351
 352   int err = Z_OK;
 353   bool done = false;
 354
 355   while (err == Z_OK || err == Z_STREAM_END) {
 356     size_t len = m_z_size  - m_deflate->avail_out;
 357     if (len) {
 358       if (m_parent_o_stream->Write(m_z_buffer, len).LastWrite() != len) {
 359         m_lasterror = wxSTREAM_WRITE_ERROR;
 360         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 361         break;
 362       }
 363       m_deflate->next_out = m_z_buffer;
 364       m_deflate->avail_out = m_z_size;
 365     }
 366
 367     if (done)
 368       break;
 369     err = deflate(m_deflate, final ? Z_FINISH : Z_FULL_FLUSH);
 370     done = m_deflate->avail_out != 0 || err == Z_STREAM_END;
 371   }
 372 }
 373
 374 size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size)
 375 {
 376   wxASSERT_MSG(m_deflate && m_z_buffer, wxT("Deflate stream not open"));
 377
 378   if (!m_deflate || !m_z_buffer)
 379   {
 380     // notice that this will make IsOk() test just below return false
 381     m_lasterror = wxSTREAM_WRITE_ERROR;
 382   }
 383
 384   if (!IsOk() || !size)
 385     return 0;
 386
 387   int err = Z_OK;
 388   m_deflate->next_in = (unsigned char *)buffer;
 389   m_deflate->avail_in = size;
 390
 391   while (err == Z_OK && m_deflate->avail_in > 0) {
 392     if (m_deflate->avail_out == 0) {
 393       m_parent_o_stream->Write(m_z_buffer, m_z_size);
 394       if (m_parent_o_stream->LastWrite() != m_z_size) {
 395         m_lasterror = wxSTREAM_WRITE_ERROR;
 396         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 397         break;
 398       }
 399
 400       m_deflate->next_out = m_z_buffer;
 401       m_deflate->avail_out = m_z_size;
 402     }
 403
 404     err = deflate(m_deflate, Z_NO_FLUSH);
 405   }
 406
 407   if (err != Z_OK) {
 408     m_lasterror = wxSTREAM_WRITE_ERROR;
 409     wxString msg(m_deflate->msg, *wxConvCurrent);
 410     if (!msg)
 411       msg = wxString::Format(_("zlib error %d"), err);
 412     wxLogError(_("Can't write to deflate stream: %s"), msg.c_str());
 413   }
 414
 415   size -= m_deflate->avail_in;
 416   m_pos += size;
 417   return size;
 418 }
 419
 420 /* static */ bool wxZlibOutputStream::CanHandleGZip()
 421 {
 422   return wxZlibInputStream::CanHandleGZip();
 423 }
 424
 425 bool wxZlibOutputStream::SetDictionary(const char *data, const size_t datalen)
 426 {
 427     return (deflateSetDictionary(m_deflate, (Bytef*)data, datalen) == Z_OK);
 428 }
 429
 430 bool wxZlibOutputStream::SetDictionary(const wxMemoryBuffer &buf)
 431 {
 432     return SetDictionary((char*)buf.GetData(), buf.GetDataLen());
 433 }
 434
 435 #endif
 436   // wxUSE_ZLIB && wxUSE_STREAMS