src/common/zstream.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        zstream.cpp
   3 // Purpose:     Compressed stream classes
   4 // Author:      Guilhem Lavaux
   5 // Modified by:
   6 // Created:     11/07/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Guilhem Lavaux
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifdef __GNUG__
  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 #elif defined(__WXMAC__) && defined(__UNIX__)
  37    #include <Kernel/net/zlib.h>
  38 #else
  39    #include <zlib.h>
  40 #endif
  41
  42 #define ZSTREAM_BUFFER_SIZE 1024
  43
  44 //////////////////////
  45 // wxZlibInputStream
  46 //////////////////////
  47
  48 wxZlibInputStream::wxZlibInputStream(wxInputStream& stream)
  49   : wxFilterInputStream(stream)
  50 {
  51   // I need a private stream buffer.
  52   m_inflate = new z_stream_s;
  53
  54   m_inflate->zalloc = (alloc_func)0;
  55   m_inflate->zfree = (free_func)0;
  56   m_inflate->opaque = (voidpf)0;
  57
  58   int err = inflateInit(m_inflate);
  59   if (err != Z_OK) {
  60     inflateEnd(m_inflate);
  61     delete m_inflate;
  62     return;
  63   }
  64
  65   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
  66   m_z_size = ZSTREAM_BUFFER_SIZE;
  67
  68   m_inflate->avail_in = 0;
  69   m_inflate->next_in = NULL;
  70 }
  71
  72 wxZlibInputStream::~wxZlibInputStream()
  73 {
  74   inflateEnd(m_inflate);
  75   delete m_inflate;
  76
  77   delete [] m_z_buffer;
  78 }
  79
  80 size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size)
  81 {
  82   int err;
  83
  84   m_inflate->next_out = (unsigned char *)buffer;
  85   m_inflate->avail_out = size;
  86
  87   while (m_inflate->avail_out > 0) {
  88     if (m_inflate->avail_in == 0) {
  89
  90       m_parent_i_stream->Read(m_z_buffer, wxMin(m_z_size, size));
  91       m_inflate->next_in = m_z_buffer;
  92       m_inflate->avail_in = m_parent_i_stream->LastRead();
  93
  94       if (m_parent_i_stream->LastError() != wxStream_NOERROR &&
  95           m_parent_i_stream->LastError() != wxStream_EOF)
  96       {
  97         m_lasterror = m_parent_i_stream->LastError();
  98         return 0; // failed to read anything
  99       }
 100
 101       if ( m_inflate->avail_in == 0 )
 102       {
 103           // EOF
 104           m_lasterror = wxStream_EOF;
 105           break;
 106       }
 107     }
 108     err = inflate(m_inflate, Z_FINISH);
 109     if (err == Z_STREAM_END)
 110       return (size - m_inflate->avail_out);
 111   }
 112
 113   return size-m_inflate->avail_out;
 114 }
 115
 116 //////////////////////
 117 // wxZlibOutputStream
 118 //////////////////////
 119
 120 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream, int level)
 121  : wxFilterOutputStream(stream)
 122 {
 123   int err;
 124
 125   m_deflate = new z_stream_s;
 126
 127   m_deflate->zalloc = (alloc_func)0;
 128   m_deflate->zfree = (free_func)0;
 129   m_deflate->opaque = (voidpf)0;
 130
 131   if (level == -1) level = Z_DEFAULT_COMPRESSION;
 132   wxASSERT_MSG(level >= 0 && level <= 9, wxT("wxZlibOutputStream compression level must be between 0 and 9!"));
 133
 134   err = deflateInit(m_deflate, level);
 135   if (err != Z_OK) {
 136     deflateEnd(m_deflate);
 137     return;
 138   }
 139
 140   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 141   m_z_size = ZSTREAM_BUFFER_SIZE;
 142
 143   m_deflate->avail_in = 0;
 144   m_deflate->next_out = m_z_buffer;
 145   m_deflate->avail_out = m_z_size;
 146 }
 147
 148 wxZlibOutputStream::~wxZlibOutputStream()
 149 {
 150   int err;
 151
 152   Sync();
 153
 154   err = deflate(m_deflate, Z_FINISH);
 155   if (err != Z_STREAM_END)
 156   {
 157     wxLogDebug( wxT("wxZlibOutputStream: an error occured while closing the stream.\n") );
 158     return;
 159   }
 160
 161   deflateEnd(m_deflate);
 162   delete m_deflate;
 163
 164   delete[] m_z_buffer;
 165 }
 166
 167 void wxZlibOutputStream::Sync()
 168 {
 169   int err;
 170
 171   m_parent_o_stream->Write(m_z_buffer, m_z_size-m_deflate->avail_out);
 172   m_deflate->next_out  = m_z_buffer;
 173   m_deflate->avail_out = m_z_size;
 174
 175   err = deflate(m_deflate, Z_FULL_FLUSH);
 176   if (err != Z_OK) {
 177     return;
 178   }
 179
 180   // Fixed by "Stefan Csomor" <csomor@advancedconcepts.ch>
 181   while( m_deflate->avail_out == 0 )
 182   {
 183      m_parent_o_stream->Write(m_z_buffer, m_z_size );
 184      m_deflate->next_out  = m_z_buffer;
 185      m_deflate->avail_out = m_z_size;
 186      err = deflate(m_deflate, Z_FULL_FLUSH);
 187      if (err != Z_OK) {
 188         return;
 189      }
 190   }
 191   // End
 192
 193   m_parent_o_stream->Write(m_z_buffer, m_z_size-m_deflate->avail_out);
 194   m_deflate->next_out  = m_z_buffer;
 195   m_deflate->avail_out = m_z_size;
 196 }
 197
 198 size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size)
 199 {
 200   int err;
 201
 202   m_deflate->next_in = (unsigned char *)buffer;
 203   m_deflate->avail_in = size;
 204
 205   while (m_deflate->avail_in > 0) {
 206
 207     if (m_deflate->avail_out == 0) {
 208       m_parent_o_stream->Write(m_z_buffer, m_z_size);
 209       if (m_parent_o_stream->LastError() != wxStream_NOERROR)
 210         return (size - m_deflate->avail_in);
 211
 212       m_deflate->next_out = m_z_buffer;
 213       m_deflate->avail_out = m_z_size;
 214     }
 215
 216     err = deflate(m_deflate, Z_NO_FLUSH);
 217     if (err != Z_OK)
 218       return (size - m_deflate->avail_in);
 219   }
 220   return size;
 221 }
 222
 223 #endif
 224   // wxUSE_ZLIB && wxUSE_STREAMS
 225