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);
  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::DoRead(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->Eof())
  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 bool wxZlibInputStream::Eof() const
  93 {
  94   if (!m_eof)
  95     return m_parent_i_stream->Eof();
  96   return m_eof;
  97 }
  98
  99 //////////////////////
 100 // wxZlibOutputStream
 101 //////////////////////
 102
 103 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream)
 104  : wxFilterOutputStream(stream)
 105 {
 106   int err;
 107
 108   m_o_streambuf = new wxStreamBuffer(*this);
 109   m_o_destroybuf = TRUE;
 110   m_deflate = new z_stream_s;
 111
 112   m_deflate->zalloc = (alloc_func)0;
 113   m_deflate->zfree = (free_func)0;
 114   m_deflate->opaque = (voidpf)0;
 115
 116   err = deflateInit(m_deflate, Z_DEFAULT_COMPRESSION);
 117   if (err != Z_OK) {
 118     deflateEnd(m_deflate);
 119     return;
 120   }
 121
 122   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 123   m_z_size = ZSTREAM_BUFFER_SIZE;
 124
 125   m_deflate->avail_in = 0;
 126   m_deflate->next_out = m_z_buffer;
 127   m_deflate->avail_out = m_z_size;
 128 }
 129
 130 wxZlibOutputStream::~wxZlibOutputStream()
 131 {
 132   int err;
 133
 134   Sync();
 135
 136   err = deflate(m_deflate, Z_FINISH);
 137   if (err != Z_STREAM_END) {
 138     wxDebugMsg(_("wxZlibOutputStream: an error occured while we was closing "
 139                "the stream.\n"));
 140     return;
 141   }
 142
 143   deflateEnd(m_deflate);
 144
 145   delete[] m_z_buffer;
 146 }
 147
 148 void wxZlibOutputStream::Sync()
 149 {
 150   int err;
 151
 152   m_parent_o_stream->Write(m_z_buffer, m_z_size-m_deflate->avail_out);
 153   m_deflate->next_out  = m_z_buffer;
 154   m_deflate->avail_out = m_z_size;
 155
 156   err = deflate(m_deflate, Z_FULL_FLUSH);
 157   if (err != Z_OK) {
 158     m_bad = TRUE;
 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::DoWrite(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->Bad())
 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 bool wxZlibOutputStream::Bad() const
 193 {
 194   if (!m_bad)
 195     return m_parent_o_stream->Bad();
 196   return m_bad;
 197 }