source: XMLIO_V2/external/src/POCO/Foundation/InflatingStream.cpp @ 80

//
// InflatingStream.cpp
//
// $Id: //poco/1.3/Foundation/src/InflatingStream.cpp#3 $
//
// 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/InflatingStream.h>
#include <Poco/Exception.h>


namespace Poco {


InflatingStreamBuf::InflatingStreamBuf(std::istream& istr, StreamType type): 
        BufferedStreamBuf(STREAM_BUFFER_SIZE, std::ios::in),
        _pIstr(&istr),
        _pOstr(0),
        _eof(false),
        _check(type != STREAM_ZIP)
{
        _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 = inflateInit2(&_zstr, 15 + (type == STREAM_GZIP ? 16 : 0));
        if (rc != Z_OK) throw IOException(zError(rc)); 

        _buffer = new char[INFLATE_BUFFER_SIZE];
}


InflatingStreamBuf::InflatingStreamBuf(std::ostream& ostr, StreamType type): 
        BufferedStreamBuf(STREAM_BUFFER_SIZE, std::ios::out),
        _pIstr(0),
        _pOstr(&ostr),
        _eof(false),
        _check(type != STREAM_ZIP)
{
        _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 = inflateInit2(&_zstr, 15 + (type == STREAM_GZIP ? 16 : 0));
        if (rc != Z_OK) throw IOException(zError(rc));

        _buffer = new char[INFLATE_BUFFER_SIZE];
}


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


int InflatingStreamBuf::close()
{
        sync();
        if (_pIstr || _pOstr)
        {
                int rc = inflateEnd(&_zstr);
                if (rc != Z_OK) throw IOException(zError(rc));
                _pIstr = 0;
                _pOstr = 0;
        }
        return 0;
}


void InflatingStreamBuf::reset()
{
        int rc = inflateReset(&_zstr);
        if (rc == Z_OK)
                _eof = false;
        else
                throw IOException(zError(rc));
}


int InflatingStreamBuf::readFromDevice(char* buffer, std::streamsize length)
{
        if (_eof || !_pIstr) return 0;

        if (_zstr.avail_in == 0)
        {
                int n = 0;
                if (_pIstr->good())
                {
                        _pIstr->read(_buffer, INFLATE_BUFFER_SIZE);
                        n = static_cast<int>(_pIstr->gcount());
                }
                if (n == 0) return 0;
                _zstr.next_in   = (unsigned char*) _buffer;
                _zstr.avail_in  = n;
        }
        _zstr.next_out  = (unsigned char*) buffer;
        _zstr.avail_out = static_cast<unsigned>(length);
        for (;;)
        {
                int rc = inflate(&_zstr, Z_NO_FLUSH);
                if (rc == Z_DATA_ERROR && !_check)
                {
                        if (_zstr.avail_in == 0)
                        {
                                if (_pIstr->good())
                                        rc = Z_OK;
                                else
                                        rc = Z_STREAM_END;
                        }
                }
                if (rc == Z_STREAM_END)
                {
                        _eof = true;
                        return static_cast<int>(length) - _zstr.avail_out;
                }
                if (rc != Z_OK) throw IOException(zError(rc));
                if (_zstr.avail_out == 0)
                        return static_cast<int>(length);
                if (_zstr.avail_in == 0)
                {
                        int n = 0;
                        if (_pIstr->good())
                        {
                                _pIstr->read(_buffer, INFLATE_BUFFER_SIZE);
                                n = static_cast<int>(_pIstr->gcount());
                        }
                        if (n > 0)
                        {
                                _zstr.next_in  = (unsigned char*) _buffer;
                                _zstr.avail_in = n;
                        }
                }
        }
}


int InflatingStreamBuf::writeToDevice(const char* buffer, std::streamsize length)
{
        if (length == 0 || !_pOstr) return 0;
        
        _zstr.next_in   = (unsigned char*) buffer;
        _zstr.avail_in  = static_cast<unsigned>(length);
        _zstr.next_out  = (unsigned char*) _buffer;
        _zstr.avail_out = INFLATE_BUFFER_SIZE;
        for (;;)
        {
                int rc = inflate(&_zstr, Z_NO_FLUSH);
                if (rc == Z_STREAM_END)
                {
                        _pOstr->write(_buffer, INFLATE_BUFFER_SIZE - _zstr.avail_out);
                        if (!_pOstr->good()) throw IOException(zError(rc));
                        break;
                }
                if (rc != Z_OK) throw IOException(zError(rc)); 
                if (_zstr.avail_out == 0)
                {
                        _pOstr->write(_buffer, INFLATE_BUFFER_SIZE);
                        if (!_pOstr->good()) throw IOException(zError(rc));
                        _zstr.next_out  = (unsigned char*) _buffer;
                        _zstr.avail_out = INFLATE_BUFFER_SIZE;
                }
                if (_zstr.avail_in == 0)
                {
                        _pOstr->write(_buffer, INFLATE_BUFFER_SIZE - _zstr.avail_out);
                        if (!_pOstr->good()) throw IOException(zError(rc)); 
                        _zstr.next_out  = (unsigned char*) _buffer;
                        _zstr.avail_out = INFLATE_BUFFER_SIZE;
                        break;
                }
        }
        return static_cast<int>(length);
}


InflatingIOS::InflatingIOS(std::ostream& ostr, InflatingStreamBuf::StreamType type):
        _buf(ostr, type)
{
        poco_ios_init(&_buf);
}


InflatingIOS::InflatingIOS(std::istream& istr, InflatingStreamBuf::StreamType type):
        _buf(istr, type)
{
        poco_ios_init(&_buf);
}


InflatingIOS::~InflatingIOS()
{
}


InflatingStreamBuf* InflatingIOS::rdbuf()
{
        return &_buf;
}


InflatingOutputStream::InflatingOutputStream(std::ostream& ostr, InflatingStreamBuf::StreamType type):
        InflatingIOS(ostr, type),
        std::ostream(&_buf)
{
}


InflatingOutputStream::~InflatingOutputStream()
{
}


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


InflatingInputStream::InflatingInputStream(std::istream& istr, InflatingStreamBuf::StreamType type):
        InflatingIOS(istr, type),
        std::istream(&_buf)
{
}


InflatingInputStream::~InflatingInputStream()
{
}


void InflatingInputStream::reset()
{
        _buf.reset();
        clear();
}


} // namespace Poco