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