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 #ifndef WX_PRECOMP
  24   #include "wx/defs.h"
  25 #endif
  26
  27 #if wxUSE_ZLIB && wxUSE_STREAMS
  28
  29 #include "wx/zstream.h"
  30 #include "wx/utils.h"
  31 #include "wx/intl.h"
  32 #include "wx/log.h"
  33 #include "zlib.h"
  34
  35 #define ZSTREAM_BUFFER_SIZE 1024
  36
  37 //////////////////////
  38 // wxZlibInputStream
  39 //////////////////////
  40
  41 wxZlibInputStream::wxZlibInputStream(wxInputStream& stream)
  42   : wxFilterInputStream(stream)
  43 {
  44   int err;
  45
  46   // I need a private stream buffer.
  47   m_i_streambuf = new wxStreamBuffer(*this, wxStreamBuffer::read);
  48   m_i_destroybuf = TRUE;
  49   m_inflate = new z_stream_s;
  50
  51   m_inflate->zalloc = (alloc_func)0;
  52   m_inflate->zfree = (free_func)0;
  53   m_inflate->opaque = (voidpf)0;
  54
  55   err = inflateInit(m_inflate);
  56   if (err != Z_OK) {
  57     inflateEnd(m_inflate);
  58     delete m_inflate;
  59     return;
  60   }
  61
  62   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
  63   m_z_size = ZSTREAM_BUFFER_SIZE;
  64
  65   m_inflate->avail_in = 0;
  66   m_inflate->next_in = NULL;
  67 }
  68
  69 wxZlibInputStream::~wxZlibInputStream()
  70 {
  71   inflateEnd(m_inflate);
  72   delete m_inflate;
  73 }
  74
  75 size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size)
  76 {
  77   int err;
  78
  79   m_inflate->next_out = (unsigned char *)buffer;
  80   m_inflate->avail_out = size;
  81
  82   while (m_inflate->avail_out > 0) {
  83     if (m_inflate->avail_in == 0) {
  84
  85       m_parent_i_stream->Read(m_z_buffer, m_z_size);
  86       m_inflate->next_in = m_z_buffer;
  87       m_inflate->avail_in = m_parent_i_stream->LastRead();
  88
  89       if (m_parent_i_stream->LastError() != wxStream_NOERROR)
  90         return (size - m_inflate->avail_in);
  91     }
  92     err = inflate(m_inflate, Z_FINISH);
  93     if (err == Z_STREAM_END)
  94       return (size - m_inflate->avail_in);
  95   }
  96
  97   return size-m_inflate->avail_in;
  98 }
  99
 100 //////////////////////
 101 // wxZlibOutputStream
 102 //////////////////////
 103
 104 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream)
 105  : wxFilterOutputStream(stream)
 106 {
 107   int err;
 108
 109   m_o_streambuf = new wxStreamBuffer(*this, wxStreamBuffer::write);
 110   m_o_destroybuf = TRUE;
 111   m_deflate = new z_stream_s;
 112
 113   m_deflate->zalloc = (alloc_func)0;
 114   m_deflate->zfree = (free_func)0;
 115   m_deflate->opaque = (voidpf)0;
 116
 117   err = deflateInit(m_deflate, Z_DEFAULT_COMPRESSION);
 118   if (err != Z_OK) {
 119     deflateEnd(m_deflate);
 120     return;
 121   }
 122
 123   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 124   m_z_size = ZSTREAM_BUFFER_SIZE;
 125
 126   m_deflate->avail_in = 0;
 127   m_deflate->next_out = m_z_buffer;
 128   m_deflate->avail_out = m_z_size;
 129 }
 130
 131 wxZlibOutputStream::~wxZlibOutputStream()
 132 {
 133   int err;
 134
 135   Sync();
 136
 137   err = deflate(m_deflate, Z_FINISH);
 138   if (err != Z_STREAM_END)
 139   {
 140     wxLogDebug( _T("wxZlibOutputStream: an error occured while closing the stream.\n") );
 141     return;
 142   }
 143
 144   deflateEnd(m_deflate);
 145
 146   delete[] m_z_buffer;
 147 }
 148
 149 void wxZlibOutputStream::Sync()
 150 {
 151   int err;
 152
 153   m_parent_o_stream->Write(m_z_buffer, m_z_size-m_deflate->avail_out);
 154   m_deflate->next_out  = m_z_buffer;
 155   m_deflate->avail_out = m_z_size;
 156
 157   err = deflate(m_deflate, Z_FULL_FLUSH);
 158   if (err != Z_OK) {
 159     return;
 160   }
 161
 162   m_parent_o_stream->Write(m_z_buffer, m_z_size-m_deflate->avail_out);
 163   m_deflate->next_out  = m_z_buffer;
 164   m_deflate->avail_out = m_z_size;
 165 }
 166
 167 size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size)
 168 {
 169   int err;
 170
 171   m_deflate->next_in = (unsigned char *)buffer;
 172   m_deflate->avail_in = size;
 173
 174   while (m_deflate->avail_in > 0) {
 175
 176     if (m_deflate->avail_out == 0) {
 177       m_parent_o_stream->Write(m_z_buffer, m_z_size);
 178       if (m_parent_o_stream->LastError() != wxStream_NOERROR)
 179         return (size - m_deflate->avail_in);
 180
 181       m_deflate->next_out = m_z_buffer;
 182       m_deflate->avail_out = m_z_size;
 183     }
 184
 185     err = deflate(m_deflate, Z_NO_FLUSH);
 186     if (err != Z_OK)
 187       return (size - m_deflate->avail_in);
 188   }
 189   return size;
 190 }
 191
 192 #endif
 193   // wxUSE_ZLIB && wxUSE_STREAMS
 194