1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/os/ossrv/compressionlibs/ziplib/inc/ezcompressor.h Fri Jun 15 03:10:57 2012 +0200
1.3 @@ -0,0 +1,127 @@
1.4 +// Copyright (c) 1999-2009 Nokia Corporation and/or its subsidiary(-ies).
1.5 +// All rights reserved.
1.6 +// This component and the accompanying materials are made available
1.7 +// under the terms of "Eclipse Public License v1.0"
1.8 +// which accompanies this distribution, and is available
1.9 +// at the URL "http://www.eclipse.org/legal/epl-v10.html".
1.10 +//
1.11 +// Initial Contributors:
1.12 +// Nokia Corporation - initial contribution.
1.13 +//
1.14 +// Contributors:
1.15 +//
1.16 +// Description:
1.17 +// Declaration for Compression class
1.18 +//
1.19 +//
1.20 +
1.21 +#ifndef __EZCOMPRESSOR_H__
1.22 +#define __EZCOMPRESSOR_H__
1.23 +
1.24 +#include <e32base.h>
1.25 +#include <ezstream.h>
1.26 +#include <ezbufman.h>
1.27 +
1.28 +/**
1.29 +The CEZCompressor class provides in-memory compression functions, including integrity checks of the uncompressed data.
1.30 +This version of the library supports only one compression method (deflation). Compression can be done in a single step
1.31 +(using CompressL()) if the buffers are large enough (for example if an input file is mmap'ed), or can be done by repeated calls
1.32 +of the DeflateL() function. The source data is compressed to the target buffer (both source and target contained within
1.33 +the buffer manager argument), and various other arguments distinguish the different compression settings.
1.34 +
1.35 +Note: In this version of the library a windowBits value of 8 is unsupported due to a problem with the window size being
1.36 +set to 256 bytes. Although a value of 8 will be accepted by the CEZCompressor constructors, as it is being changed
1.37 +internally by Zlib from 8 to 9, it will not be possible to use the same value for decompression. This is because the
1.38 +Zlib functions called by the CEZDecompressor constructors do not make the same change internally and as a result a
1.39 +KEZlibErrData is returned when calling InflateL(). It is therefore advised that for this version of the library
1.40 +windowBits of 9 is used in place of 8.
1.41 +
1.42 +@publishedAll
1.43 +@released
1.44 +*/
1.45 +class CEZCompressor : public CEZZStream
1.46 + {
1.47 +public:
1.48 + /** Compression strategy - used to tune the compression algorithm */
1.49 + enum TStrategy
1.50 + {
1.51 + /** Use for normal data */
1.52 + EDefaultStrategy = Z_DEFAULT_STRATEGY,
1.53 +
1.54 + /** Use for data produced by a filter (or predictor) */
1.55 + EFiltered = Z_FILTERED,
1.56 +
1.57 + /** Force Huffman encoding only (no string match) */
1.58 + EHuffmanOnly = Z_HUFFMAN_ONLY
1.59 + };
1.60 +
1.61 + /** Compression levels */
1.62 + enum
1.63 + {
1.64 + EDefaultCompression = Z_DEFAULT_COMPRESSION,
1.65 + ENoCompression = Z_NO_COMPRESSION,
1.66 + EBestSpeed = Z_BEST_SPEED,
1.67 + EBestCompression = Z_BEST_COMPRESSION
1.68 + };
1.69 +
1.70 + /** Window Bits - the base two logarithm of the window size (the size of the history buffer) */
1.71 + enum
1.72 + {
1.73 + EMaxWBits = MAX_WBITS
1.74 + };
1.75 +
1.76 + /** Memory level - specifies how much memory should be allocated for the internal compression state */
1.77 + enum
1.78 + {
1.79 + EDefMemLevel = MAX_MEM_LEVEL
1.80 + };
1.81 +
1.82 + /** Compression panic values */
1.83 + enum
1.84 + {
1.85 + EDeflateInitlialiserError = EUnexpected + 1,
1.86 + EDeflateTerminated
1.87 + };
1.88 +
1.89 + public:
1.90 + ~CEZCompressor();
1.91 +
1.92 + IMPORT_C static CEZCompressor* NewLC(MEZBufferManager& aInit, TInt aLevel = EDefaultCompression,
1.93 + TInt aWindowBits = EMaxWBits, TInt aMemLevel = EDefMemLevel, TStrategy aStrategy = EDefaultStrategy);
1.94 + IMPORT_C static CEZCompressor* NewL(MEZBufferManager& aInit, TInt aLevel = EDefaultCompression,
1.95 + TInt aWindowBits = EMaxWBits, TInt aMemLevel = EDefMemLevel, TStrategy aStrategy = EDefaultStrategy);
1.96 + IMPORT_C static CEZCompressor* NewLC(MEZBufferManager& aInit, const TDesC8 &aDictionary,
1.97 + TInt aLevel = EDefaultCompression, TInt aWindowBits = EMaxWBits, TInt aMemLevel = EDefMemLevel,
1.98 + TStrategy aStrategy = EDefaultStrategy);
1.99 + IMPORT_C static CEZCompressor* NewL(MEZBufferManager& aInit, const TDesC8 &aDictionary,
1.100 + TInt aLevel = EDefaultCompression, TInt aWindowBits = EMaxWBits, TInt aMemLevel = EDefMemLevel,
1.101 + TStrategy aStrategy = EDefaultStrategy);
1.102 +
1.103 + IMPORT_C void ResetL(MEZBufferManager& aInit);
1.104 +
1.105 + IMPORT_C TBool DeflateL();
1.106 +
1.107 + IMPORT_C static void CompressL(TDes8 &aDestination, const TDesC8 &aSource, TInt aLevel = EDefaultCompression);
1.108 +
1.109 + private:
1.110 + enum TDeflationState
1.111 + {
1.112 + ENoFlush,
1.113 + EFinish,
1.114 + EFinalize,
1.115 + ETerminated
1.116 + };
1.117 +
1.118 + private:
1.119 + CEZCompressor(MEZBufferManager* aInit);
1.120 + void ConstructL(TInt aLevel, const TUint8* aDictionary, TInt aLength, TInt aWindowBits, TInt aMemLevel, TStrategy aStrategy);
1.121 + void ConstructL(TInt aLevel, TInt aWindowBits, TInt aMemLevel, TStrategy aStrategy);
1.122 +
1.123 + private:
1.124 + MEZBufferManager* iBufferInit;
1.125 + TDeflationState iDeflationState;
1.126 + };
1.127 +
1.128 +#endif
1.129 +
1.130 +