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 #else
  37    #include "zlib.h"
  38 #endif
  39
  40 #define ZSTREAM_BUFFER_SIZE 1024
  41
  42 //////////////////////
  43 // wxZlibInputStream
  44 //////////////////////
  45
  46 wxZlibInputStream::wxZlibInputStream(wxInputStream& stream)
  47   : wxFilterInputStream(stream)
  48 {
  49   // I need a private stream buffer.
  50   m_inflate = new z_stream_s;
  51
  52   m_inflate->zalloc = (alloc_func)0;
  53   m_inflate->zfree = (free_func)0;
  54   m_inflate->opaque = (voidpf)0;
  55
  56   int err = inflateInit(m_inflate);
  57   if (err != Z_OK) {
  58     inflateEnd(m_inflate);
  59     delete m_inflate;
  60     return;
  61   }
  62
  63   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
  64   m_z_size = ZSTREAM_BUFFER_SIZE;
  65
  66   m_inflate->avail_in = 0;
  67   m_inflate->next_in = NULL;
  68 }
  69
  70 wxZlibInputStream::~wxZlibInputStream()
  71 {
  72   inflateEnd(m_inflate);
  73   delete m_inflate;
  74
  75   delete [] m_z_buffer;
  76 }
  77
  78 size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size)
  79 {
  80   int err;
  81
  82   m_inflate->next_out = (unsigned char *)buffer;
  83   m_inflate->avail_out = size;
  84
  85   while (m_inflate->avail_out > 0) {
  86     if (m_inflate->avail_in == 0) {
  87
  88       m_parent_i_stream->Read(m_z_buffer, wxMin(m_z_size, size));
  89       m_inflate->next_in = m_z_buffer;
  90       m_inflate->avail_in = m_parent_i_stream->LastRead();
  91
  92       wxStreamError err = m_parent_i_stream->GetLastError();
  93       if ( err != wxSTREAM_NO_ERROR && err != wxSTREAM_EOF)
  94       {
  95         m_lasterror = err;
  96         return 0; // failed to read anything
  97       }
  98
  99       if ( m_inflate->avail_in == 0 )
 100       {
 101           // EOF
 102           m_lasterror = wxSTREAM_EOF;
 103           break;
 104       }
 105     }
 106     err = inflate(m_inflate, Z_FINISH);
 107     if (err == Z_STREAM_END)
 108       return (size - m_inflate->avail_out);
 109   }
 110
 111   return size-m_inflate->avail_out;
 112 }
 113
 114 //////////////////////
 115 // wxZlibOutputStream
 116 //////////////////////
 117
 118 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream, int level)
 119  : wxFilterOutputStream(stream)
 120 {
 121   int err;
 122
 123   m_deflate = new z_stream_s;
 124
 125   m_deflate->zalloc = (alloc_func)0;
 126   m_deflate->zfree = (free_func)0;
 127   m_deflate->opaque = (voidpf)0;
 128
 129   if ( level == -1 )
 130   {
 131       level = Z_DEFAULT_COMPRESSION;
 132   }
 133   else
 134   {
 135     wxASSERT_MSG(level >= 0 && level <= 9, wxT("wxZlibOutputStream compression level must be between 0 and 9!"));
 136   }
 137
 138   err = deflateInit(m_deflate, level);
 139   if (err != Z_OK) {
 140     deflateEnd(m_deflate);
 141     return;
 142   }
 143
 144   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 145   m_z_size = ZSTREAM_BUFFER_SIZE;
 146
 147   m_deflate->avail_in = 0;
 148   m_deflate->next_out = m_z_buffer;
 149   m_deflate->avail_out = m_z_size;
 150 }
 151
 152 wxZlibOutputStream::~wxZlibOutputStream()
 153 {
 154   int err;
 155
 156   Sync();
 157
 158   err = deflate(m_deflate, Z_FINISH);
 159   if (err != Z_STREAM_END)
 160   {
 161     wxLogDebug( wxT("wxZlibOutputStream: an error occured while closing the stream.\n") );
 162     return;
 163   }
 164
 165   deflateEnd(m_deflate);
 166   delete m_deflate;
 167
 168   delete[] m_z_buffer;
 169 }
 170
 171 void wxZlibOutputStream::Sync()
 172 {
 173   int err;
 174
 175   m_parent_o_stream->Write(m_z_buffer, m_z_size-m_deflate->avail_out);
 176   m_deflate->next_out  = m_z_buffer;
 177   m_deflate->avail_out = m_z_size;
 178
 179   err = deflate(m_deflate, Z_FULL_FLUSH);
 180   if (err != Z_OK) {
 181     return;
 182   }
 183
 184   // Fixed by "Stefan Csomor" <csomor@advancedconcepts.ch>
 185   while( m_deflate->avail_out == 0 )
 186   {
 187      m_parent_o_stream->Write(m_z_buffer, m_z_size );
 188      m_deflate->next_out  = m_z_buffer;
 189      m_deflate->avail_out = m_z_size;
 190      err = deflate(m_deflate, Z_FULL_FLUSH);
 191      if (err != Z_OK) {
 192         return;
 193      }
 194   }
 195   // End
 196
 197   m_parent_o_stream->Write(m_z_buffer, m_z_size-m_deflate->avail_out);
 198   m_deflate->next_out  = m_z_buffer;
 199   m_deflate->avail_out = m_z_size;
 200 }
 201
 202 size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size)
 203 {
 204   int err;
 205
 206   m_deflate->next_in = (unsigned char *)buffer;
 207   m_deflate->avail_in = size;
 208
 209   while (m_deflate->avail_in > 0) {
 210
 211     if (m_deflate->avail_out == 0) {
 212       m_parent_o_stream->Write(m_z_buffer, m_z_size);
 213       if ( !*m_parent_o_stream )
 214         return (size - m_deflate->avail_in);
 215
 216       m_deflate->next_out = m_z_buffer;
 217       m_deflate->avail_out = m_z_size;
 218     }
 219
 220     err = deflate(m_deflate, Z_NO_FLUSH);
 221     if (err != Z_OK)
 222       return (size - m_deflate->avail_in);
 223   }
 224   return size;
 225 }
 226
 227 #endif
 228   // wxUSE_ZLIB && wxUSE_STREAMS
 229