sl@0: // Copyright (c) 2001-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: // All rights reserved.
sl@0: // This component and the accompanying materials are made available
sl@0: // under the terms of "Eclipse Public License v1.0"
sl@0: // which accompanies this distribution, and is available
sl@0: // at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: //
sl@0: // Initial Contributors:
sl@0: // Nokia Corporation - initial contribution.
sl@0: //
sl@0: // Contributors:
sl@0: //
sl@0: // Description:
sl@0: //
sl@0: 
sl@0: #if !defined(__E32STD_H__)
sl@0: #include <e32std.h>
sl@0: #endif
sl@0: 
sl@0: #if !defined(__BADICTIONARYCOMPRESSION_H__)
sl@0: #define __BADICTIONARYCOMPRESSION_H__
sl@0: 
sl@0: #include "BaAssert.h"
sl@0: 
sl@0: /**
sl@0: This class implements a stream of bits (least significant bit first) as used by the code reading dictionary-compressed resource-files
sl@0: @internalComponent
sl@0: */
sl@0: class RDictionaryCompressionBitStream
sl@0: 	{
sl@0: public:
sl@0: 	RDictionaryCompressionBitStream();
sl@0: 	void OpenL(
sl@0: 		TInt aNumberOfBitsUsedForDictionaryTokens,
sl@0: 		TInt aOffsetToFirstBit,
sl@0: 		TInt aOffsetOnePastLastBit,
sl@0: 		TBool aTransferringOwnershipOfBuffer,
sl@0: 		TUint8* aBuffer,
sl@0: 		const TBaAssert& aAssertObj);
sl@0: 	void Close();
sl@0: 	TBool EndOfStreamL() const;
sl@0: 	TInt IndexOfDictionaryEntryL(); // increments the current bit-position if it returns a value >=0; returns a negative value if the next thing in the stream is plain data rather than the index of a dictionary entry
sl@0:  	void ReadL(TDes8& aBufferToAppendTo,TBool aCalypsoFileFormat); // can only be called if IndexOfDictionaryEntry returned a negative value
sl@0: private:
sl@0: 	TBool CurrentBitIsOn() const; // does not increment the current bit-position
sl@0: 	TUint ReadIntegerL(TInt aNumberOfBits); // increments the current bit-position
sl@0: private:
sl@0: 	TInt iNumberOfBitsUsedForDictionaryTokens;
sl@0: 	TInt iOffsetToFirstBit;
sl@0: 	TInt iOffsetToCurrentBit;
sl@0: 	TInt iOffsetOnePastLastBit;
sl@0: 	TBool iOwnsBitBuffer;
sl@0: 	TUint8* iBuffer;
sl@0: 	TBaAssert iAssertObj;
sl@0: 	};
sl@0: 
sl@0: #endif
sl@0: