williamr@2: // Copyright (c) 1999-2009 Nokia Corporation and/or its subsidiary(-ies).
williamr@2: // All rights reserved.
williamr@2: // This component and the accompanying materials are made available
williamr@4: // under the terms of "Eclipse Public License v1.0"
williamr@2: // which accompanies this distribution, and is available
williamr@4: // at the URL "http://www.eclipse.org/legal/epl-v10.html".
williamr@2: //
williamr@2: // Initial Contributors:
williamr@2: // Nokia Corporation - initial contribution.
williamr@2: //
williamr@2: // Contributors:
williamr@2: //
williamr@2: // Description:
williamr@2: // Declaration for Decompression class
williamr@2: // 
williamr@2: //
williamr@2: 
williamr@2: #ifndef __EZDECOMPRESSOR_H__
williamr@2: #define __EZDECOMPRESSOR_H__
williamr@2: 
williamr@2: #include <e32base.h>
williamr@2: #include <ezstream.h>
williamr@2: #include <ezbufman.h>
williamr@2: 
williamr@2: /**
williamr@2: The CEZDecompressor class provides in-memory de-compression functions, including integrity checks of the compressed data.
williamr@2: This version of the library supports only one compression / de-compression method (deflation / inflation).  De-compression
williamr@2: can be done in a single step (using DecompressL()) if the buffers are large enough (for example if an input file is mmap'ed),
williamr@2: or can be done by repeated calls of the InflateL() function.  The source data is de-compressed to the target buffer (both source 
williamr@2: and target contained within the buffer manager argument).
williamr@2: 
williamr@4: Note: In this version of the library a windowBits value of 8 is unsupported due to a problem with the window size being 
williamr@4: set to 256 bytes. Although a value of 8 will be accepted by the CEZCompressor constructors, as it is being changed 
williamr@4: internally by Zlib from 8 to 9, it will not be possible to use the same value for decompression. This is because the 
williamr@4: Zlib functions called by the CEZDecompressor constructors do not make the same change internally and as a result a 
williamr@4: KEZlibErrData is returned when calling InflateL(). It is therefore advised that for this version of the library 
williamr@4: windowBits of 9 is used in place of 8.
williamr@4: 
williamr@2: @publishedAll
williamr@2: @released
williamr@2: */
williamr@2: class CEZDecompressor : public CEZZStream
williamr@2: 	{
williamr@2: public:
williamr@2: 	/** Decompression panic values */
williamr@2: 	enum 
williamr@2: 		{
williamr@2: 		EInflateInitlialiserError = EUnexpected + 1,
williamr@2: 		EInflateVersionError,
williamr@2: 		EInflateTerminated,
williamr@2: 		EInflateDictionaryError
williamr@2: 		};
williamr@2: 		
williamr@2: 	/** Window Bits - the base two logarithm of the window size (the size of the history buffer) */
williamr@2: 	enum
williamr@2: 		{
williamr@2: 		EMaxWBits = MAX_WBITS
williamr@2: 		};
williamr@2: 
williamr@2: public:
williamr@2: 	~CEZDecompressor();
williamr@2: 
williamr@2: 	IMPORT_C static CEZDecompressor* NewLC(MEZBufferManager& aInit, TInt aWindowBits = EMaxWBits);
williamr@2: 	IMPORT_C static CEZDecompressor* NewL(MEZBufferManager& aInit, TInt aWindowBits = EMaxWBits);
williamr@2: 
williamr@2: 	IMPORT_C static CEZDecompressor* NewLC(MEZBufferManager& aInit, const TDesC8& aDictionary, TInt aWindowBits = EMaxWBits);
williamr@2: 	IMPORT_C static CEZDecompressor* NewL(MEZBufferManager& aInit, const TDesC8& aDictionary, TInt aWindowBits = EMaxWBits);
williamr@2: 
williamr@2: 
williamr@2: 	IMPORT_C void ResetL(MEZBufferManager& aInit);
williamr@2: 	IMPORT_C TBool InflateL();
williamr@2: 
williamr@2: 	IMPORT_C static void DecompressL(TDes8 &aDestination, const TDesC8 &aSource);
williamr@4: 	
williamr@2: 	private:
williamr@2: 		enum TInflationState
williamr@2: 			{
williamr@2: 			ENoFlush,
williamr@2: 			EFinalize,
williamr@2: 			ETerminated
williamr@2: 			};
williamr@2: 
williamr@2: 	private:
williamr@2: 		void SetDictionaryL();
williamr@2: 		CEZDecompressor(MEZBufferManager* aInit);
williamr@2: 		CEZDecompressor(MEZBufferManager* aInit, const TUint8 *aDictionary, TInt aLength);
williamr@2: 		void ConstructL(TInt aWindowBits);
williamr@2: 
williamr@2: 	private:
williamr@2: 		MEZBufferManager* iBufferInit;
williamr@2: 		TInflationState iInflationState;
williamr@2: 		const TUint8* iDictionary;
williamr@2: 		TInt iDictionaryLength;
williamr@2: 	};
williamr@2: 
williamr@2: #endif
williamr@4: 
williamr@4: