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 * 
 * 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
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#ifndef _MEMORY_BYTE_GRABBER_HXX_
#define _MEMORY_BYTE_GRABBER_HXX_

#include <com/sun/star/io/XInputStream.hpp>
#include <com/sun/star/io/XSeekable.hpp>
#include <string.h>

class MemoryByteGrabber 
{
protected:
	const com::sun::star::uno::Sequence < sal_Int8 > maBuffer;
	const sal_Int8 *mpBuffer;
	sal_Int32 mnCurrent, mnEnd;
public:
	MemoryByteGrabber ( const com::sun::star::uno::Sequence < sal_Int8 > & rBuffer )
	: maBuffer ( rBuffer )
	, mpBuffer ( rBuffer.getConstArray() )
	, mnCurrent ( 0 ) 
	, mnEnd ( rBuffer.getLength() ) 
	{
	}
	MemoryByteGrabber()
	{
	}
	const sal_Int8 * getCurrentPos () { return mpBuffer + mnCurrent; }

	// XInputStream chained
	sal_Int32 SAL_CALL readBytes( com::sun::star::uno::Sequence< sal_Int8 >& aData, 
											sal_Int32 nBytesToRead ) 
		throw(com::sun::star::io::NotConnectedException, com::sun::star::io::BufferSizeExceededException, com::sun::star::io::IOException, com::sun::star::uno::RuntimeException)
	{
		if ( nBytesToRead < 0)
			throw com::sun::star::io::BufferSizeExceededException();

		if (nBytesToRead + mnCurrent > mnEnd)
			nBytesToRead = mnEnd - mnCurrent;

		aData.realloc ( nBytesToRead );
		rtl_copyMemory( aData.getArray(), mpBuffer + mnCurrent, nBytesToRead );
		mnCurrent += nBytesToRead;
		return nBytesToRead;
	}

	sal_Int32 SAL_CALL readSomeBytes( com::sun::star::uno::Sequence< sal_Int8 >& aData, 
													sal_Int32 nMaxBytesToRead ) 
		throw(com::sun::star::io::NotConnectedException, com::sun::star::io::BufferSizeExceededException, com::sun::star::io::IOException, com::sun::star::uno::RuntimeException)
	{
		return readBytes( aData, nMaxBytesToRead );	
	}
	void SAL_CALL skipBytes( sal_Int32 nBytesToSkip ) 
		throw(com::sun::star::io::NotConnectedException, com::sun::star::io::BufferSizeExceededException, com::sun::star::io::IOException, com::sun::star::uno::RuntimeException)
	{
		mnCurrent += nBytesToSkip;
	}
	sal_Int32 SAL_CALL available(  ) 
		throw(com::sun::star::io::NotConnectedException, com::sun::star::io::IOException, com::sun::star::uno::RuntimeException)
	{
		return mnEnd - mnCurrent;
	}
	void SAL_CALL closeInput(  ) 
		throw(com::sun::star::io::NotConnectedException, com::sun::star::io::IOException, com::sun::star::uno::RuntimeException)
	{
	}

	// XSeekable chained...
	sal_Int64 SAL_CALL seek( sal_Int64 location ) 
		throw(com::sun::star::lang::IllegalArgumentException, com::sun::star::io::IOException, com::sun::star::uno::RuntimeException)
	{
		if ( location < 0 || location > mnEnd )
			throw com::sun::star::lang::IllegalArgumentException ();
		mnCurrent = static_cast < sal_Int32 > ( location );
		return mnCurrent;
	}
	sal_Int64 SAL_CALL getPosition(  ) 
			throw(com::sun::star::io::IOException, com::sun::star::uno::RuntimeException)
	{
		return mnCurrent;
	}
	sal_Int64 SAL_CALL getLength(  )
			throw(com::sun::star::io::IOException, com::sun::star::uno::RuntimeException)
	{
		return mnEnd;
	}
	MemoryByteGrabber& operator >> (sal_Int8& rInt8)
	{
		if (mnCurrent + 1 > mnEnd )
			rInt8 = 0;
		else
			rInt8 = mpBuffer [mnCurrent++] & 0xFF;
		return *this;
	}
	MemoryByteGrabber& operator >> (sal_Int16& rInt16)
	{
		if (mnCurrent + 2 > mnEnd )
			rInt16 = 0;
		else
		{
			rInt16  =   mpBuffer[mnCurrent++] & 0xFF;
			rInt16 |= ( mpBuffer[mnCurrent++] & 0xFF ) << 8;
		}
		return *this;
	}
	MemoryByteGrabber& operator >> (sal_Int32& rInt32)
	{
		if (mnCurrent + 4 > mnEnd )
			rInt32 = 0;
		else
		{
			rInt32  =   mpBuffer[mnCurrent++] & 0xFF;
			rInt32 |= ( mpBuffer[mnCurrent++] & 0xFF ) << 8;
			rInt32 |= ( mpBuffer[mnCurrent++] & 0xFF ) << 16;
			rInt32 |= ( mpBuffer[mnCurrent++] & 0xFF ) << 24;
		}
		return *this;
	}

	MemoryByteGrabber& operator >> (sal_uInt8& rInt8)
	{
		if (mnCurrent + 1 > mnEnd )
			rInt8 = 0;
		else
			rInt8 = mpBuffer [mnCurrent++] & 0xFF;
		return *this;
	}
	MemoryByteGrabber& operator >> (sal_uInt16& rInt16)
	{
		if (mnCurrent + 2 > mnEnd )
			rInt16 = 0;
		else
		{
			rInt16  =   mpBuffer [mnCurrent++] & 0xFF;
			rInt16 |= ( mpBuffer [mnCurrent++] & 0xFF ) << 8;
		}
		return *this;
	}
	MemoryByteGrabber& operator >> (sal_uInt32& rInt32)
	{
		if (mnCurrent + 4 > mnEnd )
			rInt32 = 0;
		else
		{
			rInt32  =   mpBuffer [mnCurrent++] & 0xFF;
			rInt32 |= ( mpBuffer [mnCurrent++] & 0xFF ) << 8;
			rInt32 |= ( mpBuffer [mnCurrent++] & 0xFF ) << 16;
			rInt32 |= ( mpBuffer [mnCurrent++] & 0xFF ) << 24;
		}
		return *this;
	}
};

#endif