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 #if wxUSE_ZLIB && wxUSE_STREAMS
  24
  25 #include "wx/zstream.h"
  26 #include "wx/utils.h"
  27 #include "wx/intl.h"
  28 #include "wx/log.h"
  29
  30 // When using configure, the path must be "zlib.h" I don't know
  31 // what other ports (wxMac, wxMotif without configure) need here.
  32 // If we are building with configure (defines __WX_SETUP_H__),
  33 // we trust the zlib path is given as a -I option.
  34 #if defined(__WXMSW__) && !defined(__WX_SETUP_H__)
  35    #include "..\zlib\zlib.h"
  36 #else
  37    #include "zlib.h"
  38 #endif
  39
  40 #define ZSTREAM_BUFFER_SIZE 1024
  41
  42 //////////////////////
  43 // wxZlibInputStream
  44 //////////////////////
  45
  46 wxZlibInputStream::wxZlibInputStream(wxInputStream& stream)
  47   : wxFilterInputStream(stream)
  48 {
  49   int err;
  50
  51   // I need a private stream buffer.
  52   m_inflate = new z_stream_s;
  53
  54   m_inflate->zalloc = (alloc_func)0;
  55   m_inflate->zfree = (free_func)0;
  56   m_inflate->opaque = (voidpf)0;
  57
  58   err = inflateInit(m_inflate);
  59   if (err != Z_OK) {
  60     inflateEnd(m_inflate);
  61     delete m_inflate;
  62     return;
  63   }
  64
  65   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
  66   m_z_size = ZSTREAM_BUFFER_SIZE;
  67
  68   m_inflate->avail_in = 0;
  69   m_inflate->next_in = NULL;
  70 }
  71
  72 wxZlibInputStream::~wxZlibInputStream()
  73 {
  74   inflateEnd(m_inflate);
  75   delete m_inflate;
  76 }
  77
  78 size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size)
  79 {
  80   int err;
  81
  82   m_inflate->next_out = (unsigned char *)buffer;
  83   m_inflate->avail_out = size;
  84
  85   while (m_inflate->avail_out > 0) {
  86     if (m_inflate->avail_in == 0) {
  87
  88       m_parent_i_stream->Read(m_z_buffer, m_z_size);
  89       m_inflate->next_in = m_z_buffer;
  90       m_inflate->avail_in = m_parent_i_stream->LastRead();
  91
  92       if (m_parent_i_stream->LastError() != wxStream_NOERROR)
  93         return (size - m_inflate->avail_in);
  94     }
  95     err = inflate(m_inflate, Z_FINISH);
  96     if (err == Z_STREAM_END)
  97       return (size - m_inflate->avail_in);
  98   }
  99
 100   return size-m_inflate->avail_in;
 101 }
 102
 103 //////////////////////
 104 // wxZlibOutputStream
 105 //////////////////////
 106
 107 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream)
 108  : wxFilterOutputStream(stream)
 109 {
 110   int err;
 111
 112   m_deflate = new z_stream_s;
 113
 114   m_deflate->zalloc = (alloc_func)0;
 115   m_deflate->zfree = (free_func)0;
 116   m_deflate->opaque = (voidpf)0;
 117
 118   err = deflateInit(m_deflate, Z_DEFAULT_COMPRESSION);
 119   if (err != Z_OK) {
 120     deflateEnd(m_deflate);
 121     return;
 122   }
 123
 124   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 125   m_z_size = ZSTREAM_BUFFER_SIZE;
 126
 127   m_deflate->avail_in = 0;
 128   m_deflate->next_out = m_z_buffer;
 129   m_deflate->avail_out = m_z_size;
 130 }
 131
 132 wxZlibOutputStream::~wxZlibOutputStream()
 133 {
 134   int err;
 135
 136   Sync();
 137
 138   err = deflate(m_deflate, Z_FINISH);
 139   if (err != Z_STREAM_END)
 140   {
 141     wxLogDebug( _T("wxZlibOutputStream: an error occured while closing the stream.\n") );
 142     return;
 143   }
 144
 145   deflateEnd(m_deflate);
 146
 147   delete[] m_z_buffer;
 148 }
 149
 150 void wxZlibOutputStream::Sync()
 151 {
 152   int err;
 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   err = deflate(m_deflate, Z_FULL_FLUSH);
 159   if (err != Z_OK) {
 160     return;
 161   }
 162
 163   m_parent_o_stream->Write(m_z_buffer, m_z_size-m_deflate->avail_out);
 164   m_deflate->next_out  = m_z_buffer;
 165   m_deflate->avail_out = m_z_size;
 166 }
 167
 168 size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size)
 169 {
 170   int err;
 171
 172   m_deflate->next_in = (unsigned char *)buffer;
 173   m_deflate->avail_in = size;
 174
 175   while (m_deflate->avail_in > 0) {
 176
 177     if (m_deflate->avail_out == 0) {
 178       m_parent_o_stream->Write(m_z_buffer, m_z_size);
 179       if (m_parent_o_stream->LastError() != wxStream_NOERROR)
 180         return (size - m_deflate->avail_in);
 181
 182       m_deflate->next_out = m_z_buffer;
 183       m_deflate->avail_out = m_z_size;
 184     }
 185
 186     err = deflate(m_deflate, Z_NO_FLUSH);
 187     if (err != Z_OK)
 188       return (size - m_deflate->avail_in);
 189   }
 190   return size;
 191 }
 192
 193 #endif
 194   // wxUSE_ZLIB && wxUSE_STREAMS
 195