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 // normally, the compiler options should contain -I../zlib, but it is
  31 // apparently not the case for all MSW makefiles and so, unless we use
  32 // configure (which defines __WX_SETUP_H__) or it is explicitly overridden by
  33 // the user (who can define wxUSE_ZLIB_H_IN_PATH), we hardcode the path here
  34 #if defined(__WXMSW__) && !defined(__WX_SETUP_H__) && !defined(wxUSE_ZLIB_H_IN_PATH)
  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, wxMin(m_z_size, 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           m_parent_i_stream->LastError() != wxStream_EOF)
  94       {
  95         m_lasterror = m_parent_i_stream->LastError();
  96         return 0; // failed to read anything
  97       }
  98
  99       if ( m_inflate->avail_in == 0 )
 100       {
 101           // EOF
 102           m_lasterror = wxStream_EOF;
 103           break;
 104       }
 105     }
 106     err = inflate(m_inflate, Z_FINISH);
 107     if (err == Z_STREAM_END)
 108       return (size - m_inflate->avail_out);
 109   }
 110
 111   return size-m_inflate->avail_out;
 112 }
 113
 114 //////////////////////
 115 // wxZlibOutputStream
 116 //////////////////////
 117
 118 wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream, int level)
 119  : wxFilterOutputStream(stream)
 120 {
 121   int err;
 122
 123   m_deflate = new z_stream_s;
 124
 125   m_deflate->zalloc = (alloc_func)0;
 126   m_deflate->zfree = (free_func)0;
 127   m_deflate->opaque = (voidpf)0;
 128
 129   if (level == -1) level = Z_DEFAULT_COMPRESSION;
 130   wxASSERT_MSG(level >= 0 && level <= 9, wxT("wxZlibOutputStream compression level must be between 0 and 9!"));
 131
 132   err = deflateInit(m_deflate, level);
 133   if (err != Z_OK) {
 134     deflateEnd(m_deflate);
 135     return;
 136   }
 137
 138   m_z_buffer = new unsigned char[ZSTREAM_BUFFER_SIZE];
 139   m_z_size = ZSTREAM_BUFFER_SIZE;
 140
 141   m_deflate->avail_in = 0;
 142   m_deflate->next_out = m_z_buffer;
 143   m_deflate->avail_out = m_z_size;
 144 }
 145
 146 wxZlibOutputStream::~wxZlibOutputStream()
 147 {
 148   int err;
 149
 150   Sync();
 151
 152   err = deflate(m_deflate, Z_FINISH);
 153   if (err != Z_STREAM_END)
 154   {
 155     wxLogDebug( wxT("wxZlibOutputStream: an error occured while closing the stream.\n") );
 156     return;
 157   }
 158
 159   deflateEnd(m_deflate);
 160
 161   delete[] m_z_buffer;
 162 }
 163
 164 void wxZlibOutputStream::Sync()
 165 {
 166   int err;
 167
 168   m_parent_o_stream->Write(m_z_buffer, m_z_size-m_deflate->avail_out);
 169   m_deflate->next_out  = m_z_buffer;
 170   m_deflate->avail_out = m_z_size;
 171
 172   err = deflate(m_deflate, Z_FULL_FLUSH);
 173   if (err != Z_OK) {
 174     return;
 175   }
 176
 177   // Fixed by "Stefan Csomor" <csomor@advancedconcepts.ch>
 178   while( m_deflate->avail_out == 0 )
 179   {
 180      m_parent_o_stream->Write(m_z_buffer, m_z_size );
 181      m_deflate->next_out  = m_z_buffer;
 182      m_deflate->avail_out = m_z_size;
 183      err = deflate(m_deflate, Z_FULL_FLUSH);
 184      if (err != Z_OK) {
 185         return;
 186      }
 187   }
 188   // End
 189
 190   m_parent_o_stream->Write(m_z_buffer, m_z_size-m_deflate->avail_out);
 191   m_deflate->next_out  = m_z_buffer;
 192   m_deflate->avail_out = m_z_size;
 193 }
 194
 195 size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size)
 196 {
 197   int err;
 198
 199   m_deflate->next_in = (unsigned char *)buffer;
 200   m_deflate->avail_in = size;
 201
 202   while (m_deflate->avail_in > 0) {
 203
 204     if (m_deflate->avail_out == 0) {
 205       m_parent_o_stream->Write(m_z_buffer, m_z_size);
 206       if (m_parent_o_stream->LastError() != wxStream_NOERROR)
 207         return (size - m_deflate->avail_in);
 208
 209       m_deflate->next_out = m_z_buffer;
 210       m_deflate->avail_out = m_z_size;
 211     }
 212
 213     err = deflate(m_deflate, Z_NO_FLUSH);
 214     if (err != Z_OK)
 215       return (size - m_deflate->avail_in);
 216   }
 217   return size;
 218 }
 219
 220 #endif
 221   // wxUSE_ZLIB && wxUSE_STREAMS
 222