xref: /linux/include/linux/decompress/generic.h (revision 498495dba268b20e8eadd7fe93c140c68b6cc9d2)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef DECOMPRESS_GENERIC_H
3 #define DECOMPRESS_GENERIC_H
4 
5 typedef int (*decompress_fn) (unsigned char *inbuf, long len,
6 			      long (*fill)(void*, unsigned long),
7 			      long (*flush)(void*, unsigned long),
8 			      unsigned char *outbuf,
9 			      long *posp,
10 			      void(*error)(char *x));
11 
12 /* inbuf   - input buffer
13  *len     - len of pre-read data in inbuf
14  *fill    - function to fill inbuf when empty
15  *flush   - function to write out outbuf
16  *outbuf  - output buffer
17  *posp    - if non-null, input position (number of bytes read) will be
18  *	  returned here
19  *
20  *If len != 0, inbuf should contain all the necessary input data, and fill
21  *should be NULL
22  *If len = 0, inbuf can be NULL, in which case the decompressor will allocate
23  *the input buffer.  If inbuf != NULL it must be at least XXX_IOBUF_SIZE bytes.
24  *fill will be called (repeatedly...) to read data, at most XXX_IOBUF_SIZE
25  *bytes should be read per call.  Replace XXX with the appropriate decompressor
26  *name, i.e. LZMA_IOBUF_SIZE.
27  *
28  *If flush = NULL, outbuf must be large enough to buffer all the expected
29  *output.  If flush != NULL, the output buffer will be allocated by the
30  *decompressor (outbuf = NULL), and the flush function will be called to
31  *flush the output buffer at the appropriate time (decompressor and stream
32  *dependent).
33  */
34 
35 
36 /* Utility routine to detect the decompression method */
37 decompress_fn decompress_method(const unsigned char *inbuf, long len,
38 				const char **name);
39 
40 #endif
41