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 // When using configure, the path must be "zlib.h" I don't know
  31 // what other ports (wxMac, wxMotif without configure) need here.
  32 // If we are building with configure (defines __WX_SETUP_H__),
  33 // we trust the zlib path is given as a -I option.
  34 #if defined(__WXMSW__) && !defined(__WX_SETUP_H__)
  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   int err;
  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   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
  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, m_z_size);
  89       m_inflate->next_in = m_z_buffer;
  90       m_inflate->avail_in = m_parent_i_stream->LastRead();
  91
  92       if (m_parent_i_stream->LastError() != wxStream_NOERROR)
  93         return (size - m_inflate->avail_in);
  94     }
  95     err = inflate(m_inflate, Z_FINISH);
  96     if (err == Z_STREAM_END)
  97       return (size - m_inflate->avail_in);
  98   }
  99
 100   return size-m_inflate->avail_in;
 101 }
 102
 103 //////////////////////
 104 // wxZlibOutputStream
 105 //////////////////////
 106
 107 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream, int level)
 108  : wxFilterOutputStream(stream)
 109 {
 110   int err;
 111
 112   m_deflate = new z_stream_s;
 113
 114   m_deflate->zalloc = (alloc_func)0;
 115   m_deflate->zfree = (free_func)0;
 116   m_deflate->opaque = (voidpf)0;
 117
 118   if (level == -1) level = Z_DEFAULT_COMPRESSION;
 119   wxASSERT_MSG(level >= 0 && level <= 9, wxT("wxZlibOutputStream compression level must be between 0 and 9!"));
 120
 121   err = deflateInit(m_deflate, level);
 122   if (err != Z_OK) {
 123     deflateEnd(m_deflate);
 124     return;
 125   }
 126
 127   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 128   m_z_size = ZSTREAM_BUFFER_SIZE;
 129
 130   m_deflate->avail_in = 0;
 131   m_deflate->next_out = m_z_buffer;
 132   m_deflate->avail_out = m_z_size;
 133 }
 134
 135 wxZlibOutputStream::~wxZlibOutputStream()
 136 {
 137   int err;
 138
 139   Sync();
 140
 141   err = deflate(m_deflate, Z_FINISH);
 142   if (err != Z_STREAM_END)
 143   {
 144     wxLogDebug( wxT("wxZlibOutputStream: an error occured while closing the stream.\n") );
 145     return;
 146   }
 147
 148   deflateEnd(m_deflate);
 149
 150   delete[] m_z_buffer;
 151 }
 152
 153 void wxZlibOutputStream::Sync()
 154 {
 155   int err;
 156
 157   m_parent_o_stream->Write(m_z_buffer, m_z_size-m_deflate->avail_out);
 158   m_deflate->next_out  = m_z_buffer;
 159   m_deflate->avail_out = m_z_size;
 160
 161   err = deflate(m_deflate, Z_FULL_FLUSH);
 162   if (err != Z_OK) {
 163     return;
 164   }
 165
 166   // Fixed by "Stefan Csomor" <csomor@advancedconcepts.ch>
 167   while( m_deflate->avail_out == 0 )
 168   {
 169      m_parent_o_stream->Write(m_z_buffer, m_z_size );
 170      m_deflate->next_out  = m_z_buffer;
 171      m_deflate->avail_out = m_z_size;
 172      err = deflate(m_deflate, Z_FULL_FLUSH);
 173      if (err != Z_OK) {
 174         return;
 175      }
 176   }
 177   // End
 178
 179   m_parent_o_stream->Write(m_z_buffer, m_z_size-m_deflate->avail_out);
 180   m_deflate->next_out  = m_z_buffer;
 181   m_deflate->avail_out = m_z_size;
 182 }
 183
 184 size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size)
 185 {
 186   int err;
 187
 188   m_deflate->next_in = (unsigned char *)buffer;
 189   m_deflate->avail_in = size;
 190
 191   while (m_deflate->avail_in > 0) {
 192
 193     if (m_deflate->avail_out == 0) {
 194       m_parent_o_stream->Write(m_z_buffer, m_z_size);
 195       if (m_parent_o_stream->LastError() != wxStream_NOERROR)
 196         return (size - m_deflate->avail_in);
 197
 198       m_deflate->next_out = m_z_buffer;
 199       m_deflate->avail_out = m_z_size;
 200     }
 201
 202     err = deflate(m_deflate, Z_NO_FLUSH);
 203     if (err != Z_OK)
 204       return (size - m_deflate->avail_in);
 205   }
 206   return size;
 207 }
 208
 209 #endif
 210   // wxUSE_ZLIB && wxUSE_STREAMS
 211