1 package nom.tam.fits.compress;
2
3 /*
4 * #%L
5 * nom.tam FITS library
6 * %%
7 * Copyright (C) 1996 - 2024 nom-tam-fits
8 * %%
9 * This is free and unencumbered software released into the public domain.
10 *
11 * Anyone is free to copy, modify, publish, use, compile, sell, or
12 * distribute this software, either in source code form or as a compiled
13 * binary, for any purpose, commercial or non-commercial, and by any
14 * means.
15 *
16 * In jurisdictions that recognize copyright laws, the author or authors
17 * of this software dedicate any and all copyright interest in the
18 * software to the public domain. We make this dedication for the benefit
19 * of the public at large and to the detriment of our heirs and
20 * successors. We intend this dedication to be an overt act of
21 * relinquishment in perpetuity of all present and future rights to this
22 * software under copyright law.
23 *
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
27 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
28 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
29 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
30 * OTHER DEALINGS IN THE SOFTWARE.
31 * #L%
32 */
33
34 import java.io.IOException;
35 import java.io.InputStream;
36
37 import nom.tam.fits.FitsException;
38
39 /**
40 * (<i>for internal use</i>) Input stream decompression interface.
41 */
42 public interface ICompressProvider {
43
44 /**
45 * Decompresses data from an input stream.
46 *
47 * @param in
48 * the input stream containing compressed data
49 * @return a new input stream containing the decompressed data
50 * @throws IOException
51 * if there was an IO error while accessing the input stream
52 * @throws FitsException
53 * if the decompression cannot be performed for some reason that
54 * is not related to the input per se.
55 */
56 InputStream decompress(InputStream in) throws IOException, FitsException;
57
58 /**
59 * Returns the priority of this method. {@link CompressionManager} will use
60 * this to select the 'best' compression class when multiple compression
61 * classes can provide decompression support for a given input stream.
62 * Claases that have a higher priority will be preferred.
63 *
64 * @return the priority of this decompression method vs similar other
65 * compression methods that may be avaialble.
66 * @see CompressionManager
67 */
68 int priority();
69
70 /**
71 * Checks if this compression method can support the magic integer number
72 * that is used to identify the type of compression at the beginning of
73 * compressed files, and is stored as the first 2 bytes of compressed data.
74 *
75 * @param byte1
76 * the first byte of the compressed file
77 * @param byte2
78 * the second byte of the compressed file
79 * @return <code>true</code> if this class can be used to decompress the
80 * given file, or else <code>false</code>.
81 */
82 boolean provides(int byte1, int byte2);
83 }