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 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
  13 #pragma implementation "zstream.h"
  14 #endif
  15
  16 // For compilers that support precompilation, includes "wx.h".
  17 #include "wx/wxprec.h"
  18
  19 #ifdef __BORLANDC__
  20   #pragma hdrstop
  21 #endif
  22
  23 #if wxUSE_ZLIB && wxUSE_STREAMS
  24
  25 #include "wx/zstream.h"
  26 #include "wx/utils.h"
  27 #include "wx/intl.h"
  28 #include "wx/log.h"
  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 #ifdef __WIN16__
  42     ZSTREAM_BUFFER_SIZE = 4096
  43 #else
  44     ZSTREAM_BUFFER_SIZE = 16384
  45 #endif
  46 };
  47
  48 //////////////////////
  49 // wxZlibInputStream
  50 //////////////////////
  51
  52 wxZlibInputStream::wxZlibInputStream(wxInputStream& stream, int flags)
  53   : wxFilterInputStream(stream)
  54 {
  55   m_inflate = NULL;
  56   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
  57   m_z_size = ZSTREAM_BUFFER_SIZE;
  58   m_pos = 0;
  59
  60   if (m_z_buffer) {
  61     m_inflate = new z_stream_s;
  62
  63     if (m_inflate) {
  64       m_inflate->zalloc = (alloc_func)0;
  65       m_inflate->zfree = (free_func)0;
  66       m_inflate->opaque = (voidpf)0;
  67       m_inflate->avail_in = 0;
  68       m_inflate->next_in = NULL;
  69       m_inflate->next_out = NULL;
  70
  71       int bits = (flags & wxZLIB_NO_HEADER) ? -MAX_WBITS : MAX_WBITS;
  72
  73       if (inflateInit2(m_inflate, bits) == Z_OK)
  74         return;
  75     }
  76   }
  77
  78   wxLogError(_("Can't initialize zlib inflate stream."));
  79   m_lasterror = wxSTREAM_READ_ERROR;
  80 }
  81
  82 wxZlibInputStream::~wxZlibInputStream()
  83 {
  84   inflateEnd(m_inflate);
  85   delete m_inflate;
  86
  87   delete [] m_z_buffer;
  88 }
  89
  90 size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size)
  91 {
  92   wxASSERT_MSG(m_inflate && m_z_buffer, wxT("Inflate stream not open"));
  93
  94   if (!m_inflate || !m_z_buffer)
  95     m_lasterror = wxSTREAM_READ_ERROR;
  96   if (!IsOk() || !size)
  97     return 0;
  98
  99   int err = Z_OK;
 100   m_inflate->next_out = (unsigned char *)buffer;
 101   m_inflate->avail_out = size;
 102
 103   while (err == Z_OK && m_inflate->avail_out > 0) {
 104     if (m_inflate->avail_in == 0) {
 105       m_parent_i_stream->Read(m_z_buffer, m_z_size);
 106       m_inflate->next_in = m_z_buffer;
 107       m_inflate->avail_in = m_parent_i_stream->LastRead();
 108
 109       if (m_inflate->avail_in == 0) {
 110         if (m_parent_i_stream->Eof())
 111           wxLogError(_("Can't read inflate stream: unexpected EOF in underlying stream."));
 112         m_lasterror = wxSTREAM_READ_ERROR;
 113         break;
 114       }
 115     }
 116     err = inflate(m_inflate, Z_NO_FLUSH);
 117   }
 118
 119   if (err == Z_STREAM_END) {
 120     // Unread any data taken from past the end of the deflate stream, so that
 121     // any additional data can be read from the underlying stream (the crc
 122     // in a gzip for example)
 123     if (m_inflate->avail_in) {
 124       m_parent_i_stream->Ungetch(m_inflate->next_in, m_inflate->avail_in);
 125       m_inflate->avail_in = 0;
 126     }
 127     m_lasterror = wxSTREAM_EOF;
 128   } else if (err != Z_OK) {
 129     wxLogError(_("Can't read from inflate stream (zlib error %d)."), err);
 130     m_lasterror = wxSTREAM_READ_ERROR;
 131   }
 132
 133   size -= m_inflate->avail_out;
 134   m_pos += size;
 135   return size;
 136 }
 137
 138 //////////////////////
 139 // wxZlibOutputStream
 140 //////////////////////
 141
 142 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream,
 143                                        int level,
 144                                        int flags)
 145  : wxFilterOutputStream(stream)
 146 {
 147   m_deflate = NULL;
 148   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 149   m_z_size = ZSTREAM_BUFFER_SIZE;
 150   m_pos = 0;
 151
 152   if ( level == -1 )
 153   {
 154     level = Z_DEFAULT_COMPRESSION;
 155   }
 156   else
 157   {
 158     wxASSERT_MSG(level >= 0 && level <= 9, wxT("wxZlibOutputStream compression level must be between 0 and 9!"));
 159   }
 160
 161   if (m_z_buffer) {
 162      m_deflate = new z_stream_s;
 163
 164      if (m_deflate) {
 165         m_deflate->zalloc = (alloc_func)0;
 166         m_deflate->zfree = (free_func)0;
 167         m_deflate->opaque = (voidpf)0;
 168         m_deflate->avail_in = 0;
 169         m_deflate->next_out = m_z_buffer;
 170         m_deflate->avail_out = m_z_size;
 171
 172         int bits = (flags & wxZLIB_NO_HEADER) ? -MAX_WBITS : MAX_WBITS;
 173
 174         if (deflateInit2(m_deflate, level, Z_DEFLATED, bits,
 175                          8, Z_DEFAULT_STRATEGY) == Z_OK)
 176           return;
 177      }
 178   }
 179
 180   wxLogError(_("Can't initialize zlib deflate stream."));
 181   m_lasterror = wxSTREAM_WRITE_ERROR;
 182 }
 183
 184 wxZlibOutputStream::~wxZlibOutputStream()
 185 {
 186   if (m_deflate && m_z_buffer)
 187     DoFlush(true);
 188   deflateEnd(m_deflate);
 189   delete m_deflate;
 190
 191   delete[] m_z_buffer;
 192 }
 193
 194 void wxZlibOutputStream::DoFlush(bool final)
 195 {
 196   wxASSERT_MSG(m_deflate && m_z_buffer, wxT("Deflate stream not open"));
 197
 198   if (!m_deflate || !m_z_buffer)
 199     m_lasterror = wxSTREAM_WRITE_ERROR;
 200   if (!IsOk())
 201     return;
 202
 203   int err = Z_OK;
 204   bool done = false;
 205
 206   while (err == Z_OK || err == Z_STREAM_END) {
 207     size_t len = m_z_size  - m_deflate->avail_out;
 208     if (len) {
 209       if (m_parent_o_stream->Write(m_z_buffer, len).LastWrite() != len) {
 210         m_lasterror = wxSTREAM_WRITE_ERROR;
 211         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 212         break;
 213       }
 214       m_deflate->next_out = m_z_buffer;
 215       m_deflate->avail_out = m_z_size;
 216     }
 217
 218     if (done)
 219       break;
 220     err = deflate(m_deflate, final ? Z_FINISH : Z_FULL_FLUSH);
 221     done = m_deflate->avail_out != 0 || err == Z_STREAM_END;
 222   }
 223 }
 224
 225 size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size)
 226 {
 227   wxASSERT_MSG(m_deflate && m_z_buffer, wxT("Deflate stream not open"));
 228
 229   if (!m_deflate || !m_z_buffer)
 230     m_lasterror = wxSTREAM_WRITE_ERROR;
 231   if (!IsOk() || !size)
 232     return 0;
 233
 234   int err = Z_OK;
 235   m_deflate->next_in = (unsigned char *)buffer;
 236   m_deflate->avail_in = size;
 237
 238   while (err == Z_OK && m_deflate->avail_in > 0) {
 239     if (m_deflate->avail_out == 0) {
 240       m_parent_o_stream->Write(m_z_buffer, m_z_size);
 241       if (m_parent_o_stream->LastWrite() != m_z_size) {
 242         m_lasterror = wxSTREAM_WRITE_ERROR;
 243         wxLogDebug(wxT("wxZlibOutputStream: Error writing to underlying stream"));
 244         break;
 245       }
 246
 247       m_deflate->next_out = m_z_buffer;
 248       m_deflate->avail_out = m_z_size;
 249     }
 250
 251     err = deflate(m_deflate, Z_NO_FLUSH);
 252   }
 253
 254   if (err != Z_OK) {
 255     m_lasterror = wxSTREAM_WRITE_ERROR;
 256     wxLogError(_("Can't write to deflate stream (zlib error %d)."), err);
 257   }
 258
 259   size -= m_deflate->avail_in;
 260   m_pos += size;
 261   return size;
 262 }
 263
 264 #endif
 265   // wxUSE_ZLIB && wxUSE_STREAMS
 266