1 ezdecompressor.h

     1 // Copyright (c) 1999-2009 Nokia Corporation and/or its subsidiary(-ies).

     2 // All rights reserved.

     3 // This component and the accompanying materials are made available

     4 // under the terms of the License "Symbian Foundation License v1.0" to Symbian Foundation members and "Symbian Foundation End User License Agreement v1.0" to non-members

     5 // which accompanies this distribution, and is available

     6 // at the URL "http://www.symbianfoundation.org/legal/licencesv10.html".

     7 //

     8 // Initial Contributors:

     9 // Nokia Corporation - initial contribution.

    10 //

    11 // Contributors:

    12 //

    13 // Description:

    14 // EZLib: DECOMPRESSOR.H

    15 // Declaration for Decompression class

    16 // 

    17 //

    18 

    19 #ifndef __EZDECOMPRESSOR_H__

    20 #define __EZDECOMPRESSOR_H__

    21 

    22 #include <e32base.h>

    23 #include <ezstream.h>

    24 #include <ezbufman.h>

    25 

    26 /**

    27 The CEZDecompressor class provides in-memory de-compression functions, including integrity checks of the compressed data.

    28 This version of the library supports only one compression / de-compression method (deflation / inflation).  De-compression

    29 can be done in a single step (using DecompressL()) if the buffers are large enough (for example if an input file is mmap'ed),

    30 or can be done by repeated calls of the InflateL() function.  The source data is de-compressed to the target buffer (both source 

    31 and target contained within the buffer manager argument).

    32 

    33 @publishedAll

    34 @released

    35 */

    36 class CEZDecompressor : public CEZZStream

    37 	{

    38 public:

    39 	/** Decompression panic values */

    40 	enum 

    41 		{

    42 		EInflateInitlialiserError = EUnexpected + 1,

    43 		EInflateVersionError,

    44 		EInflateTerminated,

    45 		EInflateDictionaryError

    46 		};

    47 		

    48 	/** Window Bits - the base two logarithm of the window size (the size of the history buffer) */

    49 	enum

    50 		{

    51 		EMaxWBits = MAX_WBITS

    52 		};

    53 

    54 public:

    55 	~CEZDecompressor();

    56 

    57 	IMPORT_C static CEZDecompressor* NewLC(MEZBufferManager& aInit, TInt aWindowBits = EMaxWBits);

    58 	IMPORT_C static CEZDecompressor* NewL(MEZBufferManager& aInit, TInt aWindowBits = EMaxWBits);

    59 

    60 	IMPORT_C static CEZDecompressor* NewLC(MEZBufferManager& aInit, const TDesC8& aDictionary, TInt aWindowBits = EMaxWBits);

    61 	IMPORT_C static CEZDecompressor* NewL(MEZBufferManager& aInit, const TDesC8& aDictionary, TInt aWindowBits = EMaxWBits);

    62 

    63 

    64 	IMPORT_C void ResetL(MEZBufferManager& aInit);

    65 	IMPORT_C TBool InflateL();

    66 

    67 	IMPORT_C static void DecompressL(TDes8 &aDestination, const TDesC8 &aSource);

    68 

    69 	private:

    70 		enum TInflationState

    71 			{

    72 			ENoFlush,

    73 			EFinalize,

    74 			ETerminated

    75 			};

    76 

    77 	private:

    78 		void SetDictionaryL();

    79 		CEZDecompressor(MEZBufferManager* aInit);

    80 		CEZDecompressor(MEZBufferManager* aInit, const TUint8 *aDictionary, TInt aLength);

    81 		void ConstructL(TInt aWindowBits);

    82 

    83 	private:

    84 		MEZBufferManager* iBufferInit;

    85 		TInflationState iInflationState;

    86 		const TUint8* iDictionary;

    87 		TInt iDictionaryLength;

    88 	};

    89 

    90 #endif