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1 | ///////////////////////////////////////////////////////////////////////////// | |
2 | // Name: zstream.h | |
3 | // Purpose: interface of wxZlibOutputStream | |
4 | // Author: wxWidgets team | |
5 | // RCS-ID: $Id$ | |
6 | // Licence: wxWindows license | |
7 | ///////////////////////////////////////////////////////////////////////////// | |
8 | ||
9 | ||
10 | /// Compression level | |
11 | enum wxZlibCompressionLevels { | |
12 | wxZ_DEFAULT_COMPRESSION = -1, | |
13 | wxZ_NO_COMPRESSION = 0, | |
14 | wxZ_BEST_SPEED = 1, | |
15 | wxZ_BEST_COMPRESSION = 9 | |
16 | }; | |
17 | ||
18 | /// Flags | |
19 | enum wxZLibFlags { | |
20 | wxZLIB_NO_HEADER = 0, //!< raw deflate stream, no header or checksum | |
21 | wxZLIB_ZLIB = 1, //!< zlib header and checksum | |
22 | wxZLIB_GZIP = 2, //!< gzip header and checksum, requires zlib 1.2.1+ | |
23 | wxZLIB_AUTO = 3 //!< autodetect header zlib or gzip | |
24 | }; | |
25 | ||
26 | ||
27 | /** | |
28 | @class wxZlibOutputStream | |
29 | ||
30 | This stream compresses all data written to it. | |
31 | ||
32 | The compressed output can be in zlib or gzip format. | |
33 | Note that writing the gzip format requires zlib version 1.2.1 or greater | |
34 | (the builtin version does support gzip format). | |
35 | ||
36 | The stream is not seekable, wxOutputStream::SeekO() returns | |
37 | ::wxInvalidOffset. | |
38 | ||
39 | @library{wxbase} | |
40 | @category{archive,streams} | |
41 | ||
42 | @see wxOutputStream, wxZlibInputStream | |
43 | */ | |
44 | class wxZlibOutputStream : public wxFilterOutputStream | |
45 | { | |
46 | public: | |
47 | //@{ | |
48 | /** | |
49 | Creates a new write-only compressed stream. | |
50 | ||
51 | @a level means level of compression. It is number between 0 and 9 | |
52 | (including these values) where 0 means no compression and 9 best but | |
53 | slowest compression. -1 is default value (currently equivalent to 6). | |
54 | ||
55 | If the parent stream is passed as a pointer then the new filter stream | |
56 | takes ownership of it. If it is passed by reference then it does not. | |
57 | ||
58 | The @a flags wxZLIB_ZLIB and wxZLIB_GZIP specify whether the output data | |
59 | will be in zlib or gzip format. wxZLIB_ZLIB is the default. | |
60 | ||
61 | If @a flags is wxZLIB_NO_HEADER, then a raw deflate stream is output | |
62 | without either zlib or gzip headers. This is a lower level mode, which | |
63 | is not usually used directly. It can be used to embed a raw deflate | |
64 | stream in a higher level protocol. | |
65 | ||
66 | The values of the ::wxZlibCompressionLevels and ::wxZLibFlags | |
67 | enumerations can be used. | |
68 | */ | |
69 | wxZlibOutputStream(wxOutputStream& stream, int level = -1, | |
70 | int flags = wxZLIB_ZLIB); | |
71 | wxZlibOutputStream(wxOutputStream* stream, int level = -1, | |
72 | int flags = wxZLIB_ZLIB); | |
73 | //@} | |
74 | ||
75 | /** | |
76 | Returns @true if zlib library in use can handle gzip compressed data. | |
77 | */ | |
78 | static bool CanHandleGZip(); | |
79 | ||
80 | //@{ | |
81 | /** | |
82 | Sets the dictionary to the specified chunk of data. This can improve | |
83 | compression rate but note that the dictionary has to be the same when | |
84 | you deflate the data as when you inflate the data, otherwise you | |
85 | will inflate corrupted data. | |
86 | ||
87 | Returns @true if the dictionary was successfully set. | |
88 | */ | |
89 | bool SetDictionary(const char *data, const size_t datalen); | |
90 | bool SetDictionary(const wxMemoryBuffer &buf); | |
91 | //@} | |
92 | }; | |
93 | ||
94 | ||
95 | ||
96 | /** | |
97 | @class wxZlibInputStream | |
98 | ||
99 | This filter stream decompresses a stream that is in zlib or gzip format. | |
100 | Note that reading the gzip format requires zlib version 1.2.1 or greater, | |
101 | (the builtin version does support gzip format). | |
102 | ||
103 | The stream is not seekable, wxInputStream::SeekI returns ::wxInvalidOffset. | |
104 | Also wxStreamBase::GetSize() is not supported, it always returns 0. | |
105 | ||
106 | @library{wxbase} | |
107 | @category{archive,streams} | |
108 | ||
109 | @see wxInputStream, wxZlibOutputStream. | |
110 | */ | |
111 | class wxZlibInputStream : public wxFilterInputStream | |
112 | { | |
113 | public: | |
114 | //@{ | |
115 | /** | |
116 | If the parent stream is passed as a pointer then the new filter stream | |
117 | takes ownership of it. If it is passed by reference then it does not. | |
118 | ||
119 | The @a flags wxZLIB_ZLIB and wxZLIB_GZIP specify whether the input data | |
120 | is in zlib or gzip format. If wxZLIB_AUTO is used, then zlib will | |
121 | autodetect the stream type, this is the default. | |
122 | ||
123 | If @a flags is wxZLIB_NO_HEADER, then the data is assumed to be a raw | |
124 | deflate stream without either zlib or gzip headers. This is a lower level | |
125 | mode, which is not usually used directly. It can be used to read a raw | |
126 | deflate stream embedded in a higher level protocol. | |
127 | ||
128 | The values of the ::wxZLibFlags enumeration can be used. | |
129 | */ | |
130 | wxZlibInputStream(wxInputStream& stream, int flags = wxZLIB_AUTO); | |
131 | wxZlibInputStream(wxInputStream* stream, int flags = wxZLIB_AUTO); | |
132 | //@} | |
133 | ||
134 | /** | |
135 | Returns @true if zlib library in use can handle gzip compressed data. | |
136 | */ | |
137 | static bool CanHandleGZip(); | |
138 | ||
139 | //@{ | |
140 | /** | |
141 | Sets the dictionary to the specified chunk of data. This can improve | |
142 | compression rate but note that the dictionary has to be the same when | |
143 | you deflate the data as when you inflate the data, otherwise you | |
144 | will inflate corrupted data. | |
145 | ||
146 | Returns @true if the dictionary was successfully set. | |
147 | */ | |
148 | bool SetDictionary(const char *data, const size_t datalen); | |
149 | bool SetDictionary(const wxMemoryBuffer &buf); | |
150 | //@} | |
151 | }; | |
152 |