xref: /386bsd/usr/include/nonstd/bsd/nfs/nfscompress.h (revision a2142627)
1 /*
2  * Copyright (c) 1989 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Rick Macklem at The University of Guelph.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	@(#)nfscompress.h	7.2 (Berkeley) 10/2/90
37  */
38 
39 /*
40  * Definitions for the compression algorithm
41  */
42 #define NFSC_MAX	17
43 #define	NFSCRL		0xe0
44 #define	NFSCRLE(a)	(NFSCRL | ((a) - 2))
45 
46 #define	nfscput(c) \
47 		if (oleft == 0) { \
48 			MGET(om, M_WAIT, MT_DATA); \
49 			if (clget) \
50 				MCLGET(om, M_WAIT); \
51 			om->m_len = 0; \
52 			oleft = M_TRAILINGSPACE(om) - 1; \
53 			*mp = om; \
54 			mp = &om->m_next; \
55 			op = mtod(om, u_char *); \
56 		} else \
57 			oleft--; \
58 		*op++ = (c); \
59 		om->m_len++; \
60 		olen++
61 
62 #define nfscget(c) \
63 		if (ileft == 0) { \
64 			do { \
65 				m = m->m_next; \
66 			} while (m && m->m_len == 0); \
67 			if (m) { \
68 				ileft = m->m_len - 1; \
69 				ip = mtod(m, u_char *); \
70 				(c) = *ip++; \
71 			} else { \
72 				(c) = '\0'; \
73 				noteof = 0; \
74 			} \
75 		} else { \
76 			(c) = *ip++; \
77 			ileft--; \
78 		}
79