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 #ifdef __GNUG__
  12 #pragma implementation "zstream.h"
  13 #endif
  14
  15 // For compilers that support precompilation, includes "wx.h".
  16 #include "wx/wxprec.h"
  17
  18 #include "wx/zstream.h"
  19
  20 #if wxUSE_ZLIB
  21
  22 #include "wx/utils.h"
  23 #include "wx/intl.h"
  24 #include "wx/log.h"
  25 #include "../zlib/zlib.h"   // don't change this, Robert
  26
  27 #ifdef __BORLANDC__
  28 #pragma hdrstop
  29 #endif
  30
  31 #define ZSTREAM_BUFFER_SIZE 1024
  32
  33 //////////////////////
  34 // wxZlibInputStream
  35 //////////////////////
  36
  37 wxZlibInputStream::wxZlibInputStream(wxInputStream& stream)
  38   : wxFilterInputStream(stream)
  39 {
  40   int err;
  41
  42   // I need a private stream buffer.
  43   m_i_streambuf = new wxStreamBuffer(*this, wxStreamBuffer::read);
  44   m_i_destroybuf = TRUE;
  45   m_inflate = new z_stream_s;
  46
  47   m_inflate->zalloc = (alloc_func)0;
  48   m_inflate->zfree = (free_func)0;
  49   m_inflate->opaque = (voidpf)0;
  50
  51   err = inflateInit(m_inflate);
  52   if (err != Z_OK) {
  53     inflateEnd(m_inflate);
  54     delete m_inflate;
  55     return;
  56   }
  57
  58   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
  59   m_z_size = ZSTREAM_BUFFER_SIZE;
  60
  61   m_inflate->avail_in = 0;
  62   m_inflate->next_in = NULL;
  63 }
  64
  65 wxZlibInputStream::~wxZlibInputStream()
  66 {
  67   inflateEnd(m_inflate);
  68   delete m_inflate;
  69 }
  70
  71 size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size)
  72 {
  73   int err;
  74
  75   m_inflate->next_out = (unsigned char *)buffer;
  76   m_inflate->avail_out = size;
  77
  78   while (m_inflate->avail_out > 0) {
  79     if (m_inflate->avail_in == 0) {
  80
  81       m_parent_i_stream->Read(m_z_buffer, m_z_size);
  82       m_inflate->next_in = m_z_buffer;
  83       m_inflate->avail_in = m_parent_i_stream->LastRead();
  84
  85       if (m_parent_i_stream->LastError() != wxStream_NOERROR)
  86         return (size - m_inflate->avail_in);
  87     }
  88     err = inflate(m_inflate, Z_FINISH);
  89     if (err == Z_STREAM_END)
  90       return (size - m_inflate->avail_in);
  91   }
  92
  93   return size-m_inflate->avail_in;
  94 }
  95
  96 //////////////////////
  97 // wxZlibOutputStream
  98 //////////////////////
  99
 100 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream)
 101  : wxFilterOutputStream(stream)
 102 {
 103   int err;
 104
 105   m_o_streambuf = new wxStreamBuffer(*this, wxStreamBuffer::write);
 106   m_o_destroybuf = TRUE;
 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
 190   // wxUSE_ZLIB
 191