AOO410/main/comphelper/source/streaming/seqstream.cxx

/**************************************************************
 * 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * 
 *************************************************************/



// MARKER(update_precomp.py): autogen include statement, do not remove
#include "precompiled_comphelper.hxx"
#include <comphelper/seqstream.hxx>

#include <memory.h> // for memcpy

namespace comphelper
{
using namespace ::com::sun::star::lang;
using namespace ::com::sun::star::io;
using namespace ::com::sun::star::uno;
using namespace ::osl;

//---------------------------------------------------------------------------------------------
// class SequenceInputStream
//---------------------------------------------------------------------------------------------

//------------------------------------------------------------------
SequenceInputStream::SequenceInputStream(const ByteSequence& rData)
:	m_aData(rData)
,	m_nPos(0)
{
}

// checks if closed, returns available size, not mutex-protected
//------------------------------------------------------------------
inline sal_Int32 SequenceInputStream::avail()
{
	if (m_nPos == -1)
		throw NotConnectedException(::rtl::OUString(), *this);

	return m_aData.getLength() - m_nPos;
}

// com::sun::star::io::XInputStream
//------------------------------------------------------------------
sal_Int32 SAL_CALL SequenceInputStream::readBytes( Sequence<sal_Int8>& aData, sal_Int32 nBytesToRead )
	throw(NotConnectedException, BufferSizeExceededException,
		  IOException, RuntimeException)
{
	::osl::MutexGuard aGuard( m_aMutex );

	sal_Int32 nAvail = avail();

	if (nBytesToRead < 0)
		throw BufferSizeExceededException(::rtl::OUString(),*this);

	if (nAvail < nBytesToRead)
		nBytesToRead = nAvail;

	aData.realloc(nBytesToRead);
	memcpy(aData.getArray(), m_aData.getConstArray() + m_nPos, nBytesToRead);
	m_nPos += nBytesToRead;

	return nBytesToRead;
}

//------------------------------------------------------------------
sal_Int32 SAL_CALL SequenceInputStream::readSomeBytes( Sequence<sal_Int8>& aData, sal_Int32 nMaxBytesToRead )
	throw(NotConnectedException, BufferSizeExceededException,
		  IOException, RuntimeException)
{
	// all data is available at once
	return readBytes(aData, nMaxBytesToRead);
}

//------------------------------------------------------------------
void SAL_CALL SequenceInputStream::skipBytes( sal_Int32 nBytesToSkip )
	throw(NotConnectedException, BufferSizeExceededException,
		  IOException, RuntimeException)
{
	::osl::MutexGuard aGuard( m_aMutex );

	sal_Int32 nAvail = avail();

	if (nBytesToSkip < 0)
		throw BufferSizeExceededException(::rtl::OUString(),*this);

	if (nAvail < nBytesToSkip)
		nBytesToSkip = nAvail;

	m_nPos += nBytesToSkip;
}

//------------------------------------------------------------------
sal_Int32 SAL_CALL SequenceInputStream::available(  )
	throw(NotConnectedException, IOException, RuntimeException)
{
	::osl::MutexGuard aGuard( m_aMutex );

	return avail();
}

//------------------------------------------------------------------
void SAL_CALL SequenceInputStream::closeInput(  )
	throw(NotConnectedException, IOException, RuntimeException)
{
	if (m_nPos == -1)
		throw NotConnectedException(::rtl::OUString(), *this);

	m_nPos = -1;
}

void SAL_CALL SequenceInputStream::seek( sal_Int64 location ) throw (IllegalArgumentException, IOException, RuntimeException)
{
    if ( location > m_aData.getLength() || location < 0 || location > SAL_MAX_INT32 )
        throw IllegalArgumentException();
    m_nPos = (sal_Int32) location;
}

sal_Int64 SAL_CALL SequenceInputStream::getPosition() throw (IOException, RuntimeException)
{
    return m_nPos;
}

sal_Int64 SAL_CALL SequenceInputStream::getLength(  ) throw (IOException, RuntimeException)
{
    return m_aData.getLength();
}

//--------------------------------------------------------------------------
OSequenceOutputStream::OSequenceOutputStream(Sequence< sal_Int8 >& _rSeq, double _nResizeFactor, sal_Int32 _nMinimumResize, sal_Int32 _nMaximumResize)
	:m_rSequence(_rSeq)
	,m_nResizeFactor(_nResizeFactor)
	,m_nMinimumResize(_nMinimumResize)
	,m_nMaximumResize(_nMaximumResize)
	,m_nSize(0)	// starting at position 0
	,m_bConnected(sal_True)
{
	OSL_ENSURE(m_nResizeFactor > 1, "OSequenceOutputStream::OSequenceOutputStream : invalid resize factor !");
	OSL_ENSURE((m_nMaximumResize < 0) || (m_nMaximumResize > m_nMinimumResize),
		"OSequenceOutputStream::OSequenceOutputStream : these limits don't make any sense !");

	if (m_nResizeFactor <= 1)
		m_nResizeFactor = 1.3;
	if ((m_nMaximumResize >= 0) && (m_nMaximumResize <= m_nMinimumResize))
		m_nMaximumResize = m_nMinimumResize * 2;
		// this heuristic is as good as any other ... supply better parameters if you don't like it :)
}

//--------------------------------------------------------------------------
void SAL_CALL OSequenceOutputStream::writeBytes( const Sequence< sal_Int8 >& _rData ) throw(NotConnectedException, BufferSizeExceededException, IOException, RuntimeException)
{
	MutexGuard aGuard(m_aMutex);
	if (!m_bConnected)
		throw NotConnectedException();

	// ensure the sequence has enoungh space left
	if (m_nSize + _rData.getLength() > m_rSequence.getLength())
	{
		sal_Int32 nCurrentLength = m_rSequence.getLength();
		sal_Int32 nNewLength = static_cast< sal_Int32 >(
            nCurrentLength * m_nResizeFactor);

		if (m_nMinimumResize > nNewLength - nCurrentLength)
			// we have a minimum so it's not too inefficient for small sequences and small write requests
			nNewLength = nCurrentLength + m_nMinimumResize;

		if ((m_nMaximumResize > 0) && (nNewLength - nCurrentLength > m_nMaximumResize))
			// such a large step is not allowed
			nNewLength = nCurrentLength + m_nMaximumResize;

		if (nNewLength < m_nSize + _rData.getLength())
		{	// it's not enough .... the data would not fit

			// let's take the double amount of the length of the data to be written, as the next write
			// request could be as large as this one
			sal_Int32 nNewGrowth = _rData.getLength() * 2;
			if ((m_nMaximumResize > 0) && (nNewGrowth > m_nMaximumResize))
			{	// we came to the limit, again ...
				nNewGrowth = m_nMaximumResize;
				if (nNewGrowth + nCurrentLength < m_nSize + _rData.getLength())
					// but it would not fit if we respect the limit
					nNewGrowth = m_nSize + _rData.getLength() - nCurrentLength;
			}
			nNewLength = nCurrentLength + nNewGrowth;
		}

		// round it off to the next multiple of 4 ...
		nNewLength = (nNewLength + 3) / 4 * 4;

		m_rSequence.realloc(nNewLength);
	}

	OSL_ENSURE(m_rSequence.getLength() >= m_nSize + _rData.getLength(),
		"ooops ... the realloc algorithm seems to be wrong :( !");

	memcpy(m_rSequence.getArray() + m_nSize, _rData.getConstArray(), _rData.getLength());
	m_nSize += _rData.getLength();
}

//--------------------------------------------------------------------------
void SAL_CALL OSequenceOutputStream::flush(  ) throw(NotConnectedException, BufferSizeExceededException, IOException, RuntimeException)
{
	MutexGuard aGuard(m_aMutex);
	if (!m_bConnected)
		throw NotConnectedException();

    // cut the sequence to the real size
    m_rSequence.realloc(m_nSize);
}

//--------------------------------------------------------------------------
void SAL_CALL OSequenceOutputStream::closeOutput(  ) throw(NotConnectedException, BufferSizeExceededException, IOException, RuntimeException)
{
	MutexGuard aGuard(m_aMutex);
	if (!m_bConnected)
		throw NotConnectedException();

	// cut the sequence to the real size
	m_rSequence.realloc(m_nSize);
	// and don't allow any further accesses
	m_bConnected = sal_False;
}

} // namespace comphelper