Logo Search packages:      
Sourcecode: poco version File versions  Download package

DeflatingStream.cpp

//
// DeflatingStream.cpp
//
// $Id: //poco/1.2/Foundation/src/DeflatingStream.cpp#1 $
//
// Library: Foundation
// Package: Streams
// Module:  ZLibStream
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
// 
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//


#include "Poco/DeflatingStream.h"
#include "Poco/Exception.h"


namespace Poco {


DeflatingStreamBuf::DeflatingStreamBuf(std::istream& istr, StreamType type, int level): 
      BufferedStreamBuf(STREAM_BUFFER_SIZE, std::ios::in),
      _pIstr(&istr),
      _pOstr(0),
      _eof(false)
{
      _zstr.zalloc    = Z_NULL;
      _zstr.zfree     = Z_NULL;
      _zstr.opaque    = Z_NULL;
      _zstr.next_in   = 0;
      _zstr.avail_in  = 0;
      _zstr.next_out  = 0;
      _zstr.avail_out = 0;

      int rc = deflateInit2(&_zstr, level, Z_DEFLATED, 15 + (type == STREAM_GZIP ? 16 : 0), 8, Z_DEFAULT_STRATEGY);
      if (rc != Z_OK) throw IOException(zError(rc)); 

      _buffer = new char[DEFLATE_BUFFER_SIZE];
}


DeflatingStreamBuf::DeflatingStreamBuf(std::ostream& ostr, StreamType type, int level): 
      BufferedStreamBuf(STREAM_BUFFER_SIZE, std::ios::out),
      _pIstr(0),
      _pOstr(&ostr),
      _eof(false)
{
      _zstr.zalloc    = Z_NULL;
      _zstr.zfree     = Z_NULL;
      _zstr.opaque    = Z_NULL;
      _zstr.next_in   = 0;
      _zstr.avail_in  = 0;
      _zstr.next_out  = 0;
      _zstr.avail_out = 0;

      int rc = deflateInit2(&_zstr, level, Z_DEFLATED, 15 + (type == STREAM_GZIP ? 16 : 0), 8, Z_DEFAULT_STRATEGY);
      if (rc != Z_OK) throw IOException(zError(rc)); 

      _buffer = new char[DEFLATE_BUFFER_SIZE];
}


DeflatingStreamBuf::~DeflatingStreamBuf()
{
      try
      {
            close();
      }
      catch (...)
      {
      }
      delete [] _buffer;
}


int DeflatingStreamBuf::close()
{
      sync();
      if (_pIstr)
      {
            int rc = deflateEnd(&_zstr);
            if (rc != Z_OK) throw IOException(zError(rc));
            _pIstr = 0;
      }
      else if (_pOstr)
      {
            if (_zstr.next_out)
            {
                  int rc = deflate(&_zstr, Z_FINISH);
                  if (rc != Z_OK && rc != Z_STREAM_END) throw IOException(zError(rc)); 
                  _pOstr->write(_buffer, DEFLATE_BUFFER_SIZE - _zstr.avail_out);
                  if (!_pOstr->good()) throw IOException(zError(rc)); 
                  _zstr.next_out  = (unsigned char*) _buffer;
                  _zstr.avail_out = DEFLATE_BUFFER_SIZE;
                  while (rc != Z_STREAM_END)
                  {
                        rc = deflate(&_zstr, Z_FINISH);
                        if (rc != Z_OK && rc != Z_STREAM_END) throw IOException(zError(rc)); 
                        _pOstr->write(_buffer, DEFLATE_BUFFER_SIZE - _zstr.avail_out);
                        if (!_pOstr->good()) throw IOException(zError(rc)); 
                        _zstr.next_out  = (unsigned char*) _buffer;
                        _zstr.avail_out = DEFLATE_BUFFER_SIZE;
                  }
                  rc = deflateEnd(&_zstr);
                  if (rc != Z_OK) throw IOException(zError(rc));
            }
            _pOstr = 0;
      }
      return 0;
}


int DeflatingStreamBuf::readFromDevice(char* buffer, std::streamsize length)
{
      if (!_pIstr) return 0;
      if (_zstr.avail_in == 0 && !_eof)
      {
            int n = 0;
            if (_pIstr->good())
            {
                  _pIstr->read(_buffer, DEFLATE_BUFFER_SIZE);
                  n = _pIstr->gcount();
            }
            if (n > 0)
            {
                  _zstr.next_in  = (unsigned char*) _buffer;
                  _zstr.avail_in = n;
            }
            else
            {
                  _zstr.next_in  = 0;
                  _zstr.avail_in = 0;
                  _eof = true;
            }
      }
      _zstr.next_out  = (unsigned char*) buffer;
      _zstr.avail_out = length;
      for (;;)
      {
            int rc = deflate(&_zstr, _eof ? Z_FINISH : Z_NO_FLUSH);
            if (_eof && rc == Z_STREAM_END) 
            {
                  rc = deflateEnd(&_zstr);
                  if (rc != Z_OK) throw IOException(zError(rc));
                  _pIstr = 0;
                  return length - _zstr.avail_out;
            }
            if (rc != Z_OK) throw IOException(zError(rc)); 
            if (_zstr.avail_out == 0)
            {
                  return length;
            }
            if (_zstr.avail_in == 0)
            {
                  int n = 0;
                  if (_pIstr->good())
                  {
                        _pIstr->read(_buffer, DEFLATE_BUFFER_SIZE);
                        n = _pIstr->gcount();
                  }
                  if (n > 0)
                  {
                        _zstr.next_in  = (unsigned char*) _buffer;
                        _zstr.avail_in = n;
                  }
                  else
                  {
                        _zstr.next_in  = 0;
                        _zstr.avail_in = 0;
                        _eof = true;
                  }
            }
      }
}


int DeflatingStreamBuf::writeToDevice(const char* buffer, std::streamsize length)
{
      if (length == 0 || !_pOstr) return 0;

      _zstr.next_in   = (unsigned char*) buffer;
      _zstr.avail_in  = length;
      _zstr.next_out  = (unsigned char*) _buffer;
      _zstr.avail_out = DEFLATE_BUFFER_SIZE;
      for (;;)
      {
            int rc = deflate(&_zstr, Z_NO_FLUSH);
            if (rc != Z_OK) throw IOException(zError(rc)); 
            if (_zstr.avail_out == 0)
            {
                  _pOstr->write(_buffer, DEFLATE_BUFFER_SIZE);
                  if (!_pOstr->good()) throw IOException(zError(rc)); 
                  _zstr.next_out  = (unsigned char*) _buffer;
                  _zstr.avail_out = DEFLATE_BUFFER_SIZE;
            }
            if (_zstr.avail_in == 0)
            {
                  _pOstr->write(_buffer, DEFLATE_BUFFER_SIZE - _zstr.avail_out);
                  if (!_pOstr->good()) throw IOException(zError(rc)); 
                  _zstr.next_out  = (unsigned char*) _buffer;
                  _zstr.avail_out = DEFLATE_BUFFER_SIZE;
                  break;
            }
      }
      return length;
}


DeflatingIOS::DeflatingIOS(std::ostream& ostr, DeflatingStreamBuf::StreamType type, int level):
      _buf(ostr, type, level)
{
      poco_ios_init(&_buf);
}


DeflatingIOS::DeflatingIOS(std::istream& istr, DeflatingStreamBuf::StreamType type, int level):
      _buf(istr, type, level)
{
      poco_ios_init(&_buf);
}


DeflatingIOS::~DeflatingIOS()
{
}


DeflatingStreamBuf* DeflatingIOS::rdbuf()
{
      return &_buf;
}


DeflatingOutputStream::DeflatingOutputStream(std::ostream& ostr, DeflatingStreamBuf::StreamType type, int level):
      DeflatingIOS(ostr, type, level),
      std::ostream(&_buf)
{
}


DeflatingOutputStream::~DeflatingOutputStream()
{
}


int DeflatingOutputStream::close()
{
      return _buf.close();
}


DeflatingInputStream::DeflatingInputStream(std::istream& istr, DeflatingStreamBuf::StreamType type, int level):
      DeflatingIOS(istr, type, level),
      std::istream(&_buf)
{
}


DeflatingInputStream::~DeflatingInputStream()
{
}


} // namespace Poco

Generated by  Doxygen 1.6.0   Back to index