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
  33 #ifdef __WXMSW__
  34    #include "..\zlib\zlib.h"
  35 #else
  36    #include "zlib.h"
  37 #endif
  38
  39 #define ZSTREAM_BUFFER_SIZE 1024
  40
  41 //////////////////////
  42 // wxZlibInputStream
  43 //////////////////////
  44
  45 wxZlibInputStream::wxZlibInputStream(wxInputStream& stream)
  46   : wxFilterInputStream(stream)
  47 {
  48   int err;
  49
  50   // I need a private stream buffer.
  51   m_inflate = new z_stream_s;
  52
  53   m_inflate->zalloc = (alloc_func)0;
  54   m_inflate->zfree = (free_func)0;
  55   m_inflate->opaque = (voidpf)0;
  56
  57   err = inflateInit(m_inflate);
  58   if (err != Z_OK) {
  59     inflateEnd(m_inflate);
  60     delete m_inflate;
  61     return;
  62   }
  63
  64   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
  65   m_z_size = ZSTREAM_BUFFER_SIZE;
  66
  67   m_inflate->avail_in = 0;
  68   m_inflate->next_in = NULL;
  69 }
  70
  71 wxZlibInputStream::~wxZlibInputStream()
  72 {
  73   inflateEnd(m_inflate);
  74   delete m_inflate;
  75 }
  76
  77 size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size)
  78 {
  79   int err;
  80
  81   m_inflate->next_out = (unsigned char *)buffer;
  82   m_inflate->avail_out = size;
  83
  84   while (m_inflate->avail_out > 0) {
  85     if (m_inflate->avail_in == 0) {
  86
  87       m_parent_i_stream->Read(m_z_buffer, m_z_size);
  88       m_inflate->next_in = m_z_buffer;
  89       m_inflate->avail_in = m_parent_i_stream->LastRead();
  90
  91       if (m_parent_i_stream->LastError() != wxStream_NOERROR)
  92         return (size - m_inflate->avail_in);
  93     }
  94     err = inflate(m_inflate, Z_FINISH);
  95     if (err == Z_STREAM_END)
  96       return (size - m_inflate->avail_in);
  97   }
  98
  99   return size-m_inflate->avail_in;
 100 }
 101
 102 //////////////////////
 103 // wxZlibOutputStream
 104 //////////////////////
 105
 106 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream)
 107  : wxFilterOutputStream(stream)
 108 {
 109   int err;
 110
 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