1 | // |
2 | // InflatingStream.h |
3 | // |
4 | // Library: Foundation |
5 | // Package: Streams |
6 | // Module: ZLibStream |
7 | // |
8 | // Definition of the InflatingInputStream and InflatingOutputStream classes. |
9 | // |
10 | // Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH. |
11 | // and Contributors. |
12 | // |
13 | // SPDX-License-Identifier: BSL-1.0 |
14 | // |
15 | |
16 | |
17 | #ifndef Foundation_InflatingStream_INCLUDED |
18 | #define Foundation_InflatingStream_INCLUDED |
19 | |
20 | |
21 | #include "Poco/Foundation.h" |
22 | #include "Poco/BufferedStreamBuf.h" |
23 | #include <istream> |
24 | #include <ostream> |
25 | #if defined(POCO_UNBUNDLED_ZLIB) |
26 | #include <zlib.h> |
27 | #else |
28 | #include "Poco/zlib.h" |
29 | #endif |
30 | |
31 | |
32 | namespace Poco { |
33 | |
34 | |
35 | class Foundation_API InflatingStreamBuf: public BufferedStreamBuf |
36 | /// This is the streambuf class used by InflatingInputStream and InflatingOutputStream. |
37 | /// The actual work is delegated to zlib (see http://zlib.net). |
38 | /// Both zlib (deflate) streams and gzip streams are supported. |
39 | /// Output streams should always call close() to ensure |
40 | /// proper completion of decompression. |
41 | { |
42 | public: |
43 | enum StreamType |
44 | { |
45 | STREAM_ZLIB, /// Expect a zlib header, use Adler-32 checksum. |
46 | STREAM_GZIP, /// Expect a gzip header, use CRC-32 checksum. |
47 | STREAM_ZIP /// STREAM_ZIP is handled as STREAM_ZLIB, except that we do not check the ADLER32 value (must be checked by caller) |
48 | }; |
49 | |
50 | InflatingStreamBuf(std::istream& istr, StreamType type); |
51 | /// Creates an InflatingStreamBuf for expanding the compressed data read from |
52 | /// the give input stream. |
53 | |
54 | InflatingStreamBuf(std::istream& istr, int windowBits); |
55 | /// Creates an InflatingStreamBuf for expanding the compressed data read from |
56 | /// the given input stream. |
57 | /// |
58 | /// Please refer to the zlib documentation of inflateInit2() for a description |
59 | /// of the windowBits parameter. |
60 | |
61 | InflatingStreamBuf(std::ostream& ostr, StreamType type); |
62 | /// Creates an InflatingStreamBuf for expanding the compressed data passed through |
63 | /// and forwarding it to the given output stream. |
64 | |
65 | InflatingStreamBuf(std::ostream& ostr, int windowBits); |
66 | /// Creates an InflatingStreamBuf for expanding the compressed data passed through |
67 | /// and forwarding it to the given output stream. |
68 | /// |
69 | /// Please refer to the zlib documentation of inflateInit2() for a description |
70 | /// of the windowBits parameter. |
71 | |
72 | ~InflatingStreamBuf(); |
73 | /// Destroys the InflatingStreamBuf. |
74 | |
75 | int close(); |
76 | /// Finishes up the stream. |
77 | /// |
78 | /// Must be called when inflating to an output stream. |
79 | |
80 | void reset(); |
81 | /// Resets the stream buffer. |
82 | |
83 | protected: |
84 | int readFromDevice(char* buffer, std::streamsize length); |
85 | int writeToDevice(const char* buffer, std::streamsize length); |
86 | int sync(); |
87 | |
88 | private: |
89 | enum |
90 | { |
91 | STREAM_BUFFER_SIZE = 1024, |
92 | INFLATE_BUFFER_SIZE = 32768 |
93 | }; |
94 | |
95 | std::istream* _pIstr; |
96 | std::ostream* _pOstr; |
97 | char* _buffer; |
98 | z_stream _zstr; |
99 | bool _eof; |
100 | bool _check; |
101 | }; |
102 | |
103 | |
104 | class Foundation_API InflatingIOS: public virtual std::ios |
105 | /// The base class for InflatingOutputStream and InflatingInputStream. |
106 | /// |
107 | /// This class is needed to ensure the correct initialization |
108 | /// order of the stream buffer and base classes. |
109 | { |
110 | public: |
111 | InflatingIOS(std::ostream& ostr, InflatingStreamBuf::StreamType type = InflatingStreamBuf::STREAM_ZLIB); |
112 | /// Creates an InflatingIOS for expanding the compressed data passed through |
113 | /// and forwarding it to the given output stream. |
114 | |
115 | InflatingIOS(std::ostream& ostr, int windowBits); |
116 | /// Creates an InflatingIOS for expanding the compressed data passed through |
117 | /// and forwarding it to the given output stream. |
118 | /// |
119 | /// Please refer to the zlib documentation of inflateInit2() for a description |
120 | /// of the windowBits parameter. |
121 | |
122 | InflatingIOS(std::istream& istr, InflatingStreamBuf::StreamType type = InflatingStreamBuf::STREAM_ZLIB); |
123 | /// Creates an InflatingIOS for expanding the compressed data read from |
124 | /// the given input stream. |
125 | |
126 | InflatingIOS(std::istream& istr, int windowBits); |
127 | /// Creates an InflatingIOS for expanding the compressed data read from |
128 | /// the given input stream. |
129 | /// |
130 | /// Please refer to the zlib documentation of inflateInit2() for a description |
131 | /// of the windowBits parameter. |
132 | |
133 | ~InflatingIOS(); |
134 | /// Destroys the InflatingIOS. |
135 | |
136 | InflatingStreamBuf* rdbuf(); |
137 | /// Returns a pointer to the underlying stream buffer. |
138 | |
139 | protected: |
140 | InflatingStreamBuf _buf; |
141 | }; |
142 | |
143 | |
144 | class Foundation_API InflatingOutputStream: public std::ostream, public InflatingIOS |
145 | /// This stream decompresses all data passing through it |
146 | /// using zlib's inflate algorithm. |
147 | /// |
148 | /// After all data has been written to the stream, close() |
149 | /// must be called to ensure completion of decompression. |
150 | { |
151 | public: |
152 | InflatingOutputStream(std::ostream& ostr, InflatingStreamBuf::StreamType type = InflatingStreamBuf::STREAM_ZLIB); |
153 | /// Creates an InflatingOutputStream for expanding the compressed data passed through |
154 | /// and forwarding it to the given output stream. |
155 | |
156 | InflatingOutputStream(std::ostream& ostr, int windowBits); |
157 | /// Creates an InflatingOutputStream for expanding the compressed data passed through |
158 | /// and forwarding it to the given output stream. |
159 | /// |
160 | /// Please refer to the zlib documentation of inflateInit2() for a description |
161 | /// of the windowBits parameter. |
162 | |
163 | ~InflatingOutputStream(); |
164 | /// Destroys the InflatingOutputStream. |
165 | |
166 | int close(); |
167 | /// Finishes up the stream. |
168 | /// |
169 | /// Must be called to ensure all data is properly written to |
170 | /// the target output stream. |
171 | }; |
172 | |
173 | |
174 | class Foundation_API InflatingInputStream: public std::istream, public InflatingIOS |
175 | /// This stream decompresses all data passing through it |
176 | /// using zlib's inflate algorithm. |
177 | /// Example: |
178 | /// std::ifstream istr("data.gz", std::ios::binary); |
179 | /// InflatingInputStream inflater(istr, InflatingStreamBuf::STREAM_GZIP); |
180 | /// std::string data; |
181 | /// inflater >> data; |
182 | /// |
183 | /// The underlying input stream can contain more than one gzip/deflate stream. |
184 | /// After a gzip/deflate stream has been processed, reset() can be called |
185 | /// to inflate the next stream. |
186 | { |
187 | public: |
188 | InflatingInputStream(std::istream& istr, InflatingStreamBuf::StreamType type = InflatingStreamBuf::STREAM_ZLIB); |
189 | /// Creates an InflatingInputStream for expanding the compressed data read from |
190 | /// the given input stream. |
191 | |
192 | InflatingInputStream(std::istream& istr, int windowBits); |
193 | /// Creates an InflatingInputStream for expanding the compressed data read from |
194 | /// the given input stream. |
195 | /// |
196 | /// Please refer to the zlib documentation of inflateInit2() for a description |
197 | /// of the windowBits parameter. |
198 | |
199 | ~InflatingInputStream(); |
200 | /// Destroys the InflatingInputStream. |
201 | |
202 | void reset(); |
203 | /// Resets the zlib machinery so that another zlib stream can be read from |
204 | /// the same underlying input stream. |
205 | }; |
206 | |
207 | |
208 | } // namespace Poco |
209 | |
210 | |
211 | #endif // Foundation_InflatingStream_INCLUDED |
212 | |