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 "wx/log.h"
  22 #include "../zlib/zlib.h"   // don't change this, Robert
  23
  24 #ifdef __BORLANDC__
  25 #pragma hdrstop
  26 #endif
  27
  28 #define ZSTREAM_BUFFER_SIZE 1024
  29
  30 //////////////////////
  31 // wxZlibInputStream
  32 //////////////////////
  33
  34 wxZlibInputStream::wxZlibInputStream(wxInputStream& stream)
  35   : wxFilterInputStream(stream)
  36 {
  37   int err;
  38
  39   // I need a private stream buffer.
  40   m_i_streambuf = new wxStreamBuffer(*this, wxStreamBuffer::read);
  41   m_i_destroybuf = TRUE;
  42   m_inflate = new z_stream_s;
  43
  44   m_inflate->zalloc = (alloc_func)0;
  45   m_inflate->zfree = (free_func)0;
  46   m_inflate->opaque = (voidpf)0;
  47
  48   err = inflateInit(m_inflate);
  49   if (err != Z_OK) {
  50     inflateEnd(m_inflate);
  51     delete m_inflate;
  52     return;
  53   }
  54
  55   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
  56   m_z_size = ZSTREAM_BUFFER_SIZE;
  57
  58   m_inflate->avail_in = 0;
  59   m_inflate->next_in = NULL;
  60 }
  61
  62 wxZlibInputStream::~wxZlibInputStream()
  63 {
  64   inflateEnd(m_inflate);
  65   delete m_inflate;
  66 }
  67
  68 size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size)
  69 {
  70   int err;
  71
  72   m_inflate->next_out = (unsigned char *)buffer;
  73   m_inflate->avail_out = size;
  74
  75   while (m_inflate->avail_out > 0) {
  76     if (m_inflate->avail_in == 0) {
  77
  78       m_parent_i_stream->Read(m_z_buffer, m_z_size);
  79       m_inflate->next_in = m_z_buffer;
  80       m_inflate->avail_in = m_parent_i_stream->LastRead();
  81
  82       if (m_parent_i_stream->LastError() != wxStream_NOERROR)
  83         return (size - m_inflate->avail_in);
  84     }
  85     err = inflate(m_inflate, Z_FINISH);
  86     if (err == Z_STREAM_END)
  87       return (size - m_inflate->avail_in);
  88   }
  89
  90   return size-m_inflate->avail_in;
  91 }
  92
  93 //////////////////////
  94 // wxZlibOutputStream
  95 //////////////////////
  96
  97 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream)
  98  : wxFilterOutputStream(stream)
  99 {
 100   int err;
 101
 102   m_o_streambuf = new wxStreamBuffer(*this, wxStreamBuffer::write);
 103   m_o_destroybuf = TRUE;
 104   m_deflate = new z_stream_s;
 105
 106   m_deflate->zalloc = (alloc_func)0;
 107   m_deflate->zfree = (free_func)0;
 108   m_deflate->opaque = (voidpf)0;
 109
 110   err = deflateInit(m_deflate, Z_DEFAULT_COMPRESSION);
 111   if (err != Z_OK) {
 112     deflateEnd(m_deflate);
 113     return;
 114   }
 115
 116   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 117   m_z_size = ZSTREAM_BUFFER_SIZE;
 118
 119   m_deflate->avail_in = 0;
 120   m_deflate->next_out = m_z_buffer;
 121   m_deflate->avail_out = m_z_size;
 122 }
 123
 124 wxZlibOutputStream::~wxZlibOutputStream()
 125 {
 126   int err;
 127
 128   Sync();
 129
 130   err = deflate(m_deflate, Z_FINISH);
 131   if (err != Z_STREAM_END)
 132   {
 133     wxLogDebug( "wxZlibOutputStream: an error occured while closing the stream.\n" );
 134     return;
 135   }
 136
 137   deflateEnd(m_deflate);
 138
 139   delete[] m_z_buffer;
 140 }
 141
 142 void wxZlibOutputStream::Sync()
 143 {
 144   int err;
 145
 146   m_parent_o_stream->Write(m_z_buffer, m_z_size-m_deflate->avail_out);
 147   m_deflate->next_out  = m_z_buffer;
 148   m_deflate->avail_out = m_z_size;
 149
 150   err = deflate(m_deflate, Z_FULL_FLUSH);
 151   if (err != Z_OK) {
 152     return;
 153   }
 154
 155   m_parent_o_stream->Write(m_z_buffer, m_z_size-m_deflate->avail_out);
 156   m_deflate->next_out  = m_z_buffer;
 157   m_deflate->avail_out = m_z_size;
 158 }
 159
 160 size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size)
 161 {
 162   int err;
 163
 164   m_deflate->next_in = (unsigned char *)buffer;
 165   m_deflate->avail_in = size;
 166
 167   while (m_deflate->avail_in > 0) {
 168
 169     if (m_deflate->avail_out == 0) {
 170       m_parent_o_stream->Write(m_z_buffer, m_z_size);
 171       if (m_parent_o_stream->LastError() != wxStream_NOERROR)
 172         return (size - m_deflate->avail_in);
 173
 174       m_deflate->next_out = m_z_buffer;
 175       m_deflate->avail_out = m_z_size;
 176     }
 177
 178     err = deflate(m_deflate, Z_NO_FLUSH);
 179     if (err != Z_OK)
 180       return (size - m_deflate->avail_in);
 181   }
 182   return size;
 183 }