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 #include <wx/stream.h>
  18 #include <wx/zstream.h>
  19 #include <wx/utils.h>
  20 #include <wx/intl.h>
  21 #include "../zlib/zlib.h"   // don't change this, Robert
  22
  23 #ifdef __BORLANDC__
  24 #pragma hdrstop
  25 #endif
  26
  27 #define ZSTREAM_BUFFER_SIZE 1024
  28
  29 //////////////////////
  30 // wxZlibInputStream
  31 //////////////////////
  32
  33 wxZlibInputStream::wxZlibInputStream(wxInputStream& stream)
  34   : wxFilterInputStream(stream)
  35 {
  36   int err;
  37
  38   // I need a private stream buffer.
  39   m_i_streambuf = new wxStreamBuffer(*this, wxStreamBuffer::read);
  40   m_i_destroybuf = TRUE;
  41   m_inflate = new z_stream_s;
  42
  43   m_inflate->zalloc = (alloc_func)0;
  44   m_inflate->zfree = (free_func)0;
  45   m_inflate->opaque = (voidpf)0;
  46
  47   err = inflateInit(m_inflate);
  48   if (err != Z_OK) {
  49     inflateEnd(m_inflate);
  50     delete m_inflate;
  51     return;
  52   }
  53
  54   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
  55   m_z_size = ZSTREAM_BUFFER_SIZE;
  56
  57   m_inflate->avail_in = 0;
  58   m_inflate->next_in = NULL;
  59 }
  60
  61 wxZlibInputStream::~wxZlibInputStream()
  62 {
  63   inflateEnd(m_inflate);
  64   delete m_inflate;
  65 }
  66
  67 size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size)
  68 {
  69   int err;
  70
  71   m_inflate->next_out = (unsigned char *)buffer;
  72   m_inflate->avail_out = size;
  73
  74   while (m_inflate->avail_out > 0) {
  75     if (m_inflate->avail_in == 0) {
  76
  77       m_parent_i_stream->Read(m_z_buffer, m_z_size);
  78       m_inflate->next_in = m_z_buffer;
  79       m_inflate->avail_in = m_parent_i_stream->LastRead();
  80
  81       if (m_parent_i_stream->LastError() != wxStream_NOERROR)
  82         return (size - m_inflate->avail_in);
  83     }
  84     err = inflate(m_inflate, Z_FINISH);
  85     if (err == Z_STREAM_END)
  86       return (size - m_inflate->avail_in);
  87   }
  88
  89   return size-m_inflate->avail_in;
  90 }
  91
  92 //////////////////////
  93 // wxZlibOutputStream
  94 //////////////////////
  95
  96 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream)
  97  : wxFilterOutputStream(stream)
  98 {
  99   int err;
 100
 101   m_o_streambuf = new wxStreamBuffer(*this, wxStreamBuffer::write);
 102   m_o_destroybuf = TRUE;
 103   m_deflate = new z_stream_s;
 104
 105   m_deflate->zalloc = (alloc_func)0;
 106   m_deflate->zfree = (free_func)0;
 107   m_deflate->opaque = (voidpf)0;
 108
 109   err = deflateInit(m_deflate, Z_DEFAULT_COMPRESSION);
 110   if (err != Z_OK) {
 111     deflateEnd(m_deflate);
 112     return;
 113   }
 114
 115   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 116   m_z_size = ZSTREAM_BUFFER_SIZE;
 117
 118   m_deflate->avail_in = 0;
 119   m_deflate->next_out = m_z_buffer;
 120   m_deflate->avail_out = m_z_size;
 121 }
 122
 123 wxZlibOutputStream::~wxZlibOutputStream()
 124 {
 125   int err;
 126
 127   Sync();
 128
 129   err = deflate(m_deflate, Z_FINISH);
 130   if (err != Z_STREAM_END) {
 131     wxDebugMsg(_("wxZlibOutputStream: an error occured while we was closing "
 132                "the stream.\n"));
 133     return;
 134   }
 135
 136   deflateEnd(m_deflate);
 137
 138   delete[] m_z_buffer;
 139 }
 140
 141 void wxZlibOutputStream::Sync()
 142 {
 143   int err;
 144
 145   m_parent_o_stream->Write(m_z_buffer, m_z_size-m_deflate->avail_out);
 146   m_deflate->next_out  = m_z_buffer;
 147   m_deflate->avail_out = m_z_size;
 148
 149   err = deflate(m_deflate, Z_FULL_FLUSH);
 150   if (err != Z_OK) {
 151     return;
 152   }
 153
 154   m_parent_o_stream->Write(m_z_buffer, m_z_size-m_deflate->avail_out);
 155   m_deflate->next_out  = m_z_buffer;
 156   m_deflate->avail_out = m_z_size;
 157 }
 158
 159 size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size)
 160 {
 161   int err;
 162
 163   m_deflate->next_in = (unsigned char *)buffer;
 164   m_deflate->avail_in = size;
 165
 166   while (m_deflate->avail_in > 0) {
 167
 168     if (m_deflate->avail_out == 0) {
 169       m_parent_o_stream->Write(m_z_buffer, m_z_size);
 170       if (m_parent_o_stream->LastError() != wxStream_NOERROR)
 171         return (size - m_deflate->avail_in);
 172
 173       m_deflate->next_out = m_z_buffer;
 174       m_deflate->avail_out = m_z_size;
 175     }
 176
 177     err = deflate(m_deflate, Z_NO_FLUSH);
 178     if (err != Z_OK)
 179       return (size - m_deflate->avail_in);
 180   }
 181   return size;
 182 }