|
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 "Eclipse Public License v1.0" |
|
5 // which accompanies this distribution, and is available |
|
6 // at the URL "http://www.eclipse.org/legal/epl-v10.html". |
|
7 // |
|
8 // Initial Contributors: |
|
9 // Nokia Corporation - initial contribution. |
|
10 // |
|
11 // Contributors: |
|
12 // |
|
13 // Description: |
|
14 // Declaration for Decompression class |
|
15 // |
|
16 // |
|
17 |
|
18 #ifndef __EZDECOMPRESSOR_H__ |
|
19 #define __EZDECOMPRESSOR_H__ |
|
20 |
|
21 #include <e32base.h> |
|
22 #include <ezstream.h> |
|
23 #include <ezbufman.h> |
|
24 |
|
25 /** |
|
26 The CEZDecompressor class provides in-memory de-compression functions, including integrity checks of the compressed data. |
|
27 This version of the library supports only one compression / de-compression method (deflation / inflation). De-compression |
|
28 can be done in a single step (using DecompressL()) if the buffers are large enough (for example if an input file is mmap'ed), |
|
29 or can be done by repeated calls of the InflateL() function. The source data is de-compressed to the target buffer (both source |
|
30 and target contained within the buffer manager argument). |
|
31 |
|
32 Note: In this version of the library a windowBits value of 8 is unsupported due to a problem with the window size being |
|
33 set to 256 bytes. Although a value of 8 will be accepted by the CEZCompressor constructors, as it is being changed |
|
34 internally by Zlib from 8 to 9, it will not be possible to use the same value for decompression. This is because the |
|
35 Zlib functions called by the CEZDecompressor constructors do not make the same change internally and as a result a |
|
36 KEZlibErrData is returned when calling InflateL(). It is therefore advised that for this version of the library |
|
37 windowBits of 9 is used in place of 8. |
|
38 |
|
39 @publishedAll |
|
40 @released |
|
41 */ |
|
42 class CEZDecompressor : public CEZZStream |
|
43 { |
|
44 public: |
|
45 /** Decompression panic values */ |
|
46 enum |
|
47 { |
|
48 EInflateInitlialiserError = EUnexpected + 1, |
|
49 EInflateVersionError, |
|
50 EInflateTerminated, |
|
51 EInflateDictionaryError |
|
52 }; |
|
53 |
|
54 /** Window Bits - the base two logarithm of the window size (the size of the history buffer) */ |
|
55 enum |
|
56 { |
|
57 EMaxWBits = MAX_WBITS |
|
58 }; |
|
59 |
|
60 public: |
|
61 ~CEZDecompressor(); |
|
62 |
|
63 IMPORT_C static CEZDecompressor* NewLC(MEZBufferManager& aInit, TInt aWindowBits = EMaxWBits); |
|
64 IMPORT_C static CEZDecompressor* NewL(MEZBufferManager& aInit, TInt aWindowBits = EMaxWBits); |
|
65 |
|
66 IMPORT_C static CEZDecompressor* NewLC(MEZBufferManager& aInit, const TDesC8& aDictionary, TInt aWindowBits = EMaxWBits); |
|
67 IMPORT_C static CEZDecompressor* NewL(MEZBufferManager& aInit, const TDesC8& aDictionary, TInt aWindowBits = EMaxWBits); |
|
68 |
|
69 |
|
70 IMPORT_C void ResetL(MEZBufferManager& aInit); |
|
71 IMPORT_C TBool InflateL(); |
|
72 |
|
73 IMPORT_C static void DecompressL(TDes8 &aDestination, const TDesC8 &aSource); |
|
74 |
|
75 private: |
|
76 enum TInflationState |
|
77 { |
|
78 ENoFlush, |
|
79 EFinalize, |
|
80 ETerminated |
|
81 }; |
|
82 |
|
83 private: |
|
84 void SetDictionaryL(); |
|
85 CEZDecompressor(MEZBufferManager* aInit); |
|
86 CEZDecompressor(MEZBufferManager* aInit, const TUint8 *aDictionary, TInt aLength); |
|
87 void ConstructL(TInt aWindowBits); |
|
88 |
|
89 private: |
|
90 MEZBufferManager* iBufferInit; |
|
91 TInflationState iInflationState; |
|
92 const TUint8* iDictionary; |
|
93 TInt iDictionaryLength; |
|
94 }; |
|
95 |
|
96 #endif |
|
97 |
|
98 |