xref: /illumos-gate/usr/src/lib/libpkg/common/nhash.c (revision 8119dad84d6416f13557b0ba8e2aaf9064cbcfd3)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 
28 #include <stdio.h>
29 #include <string.h>
30 #include <stdlib.h>
31 #include <strings.h>
32 #include "pkglib.h"
33 #include "nhash.h"
34 #include "pkglocale.h"
35 
36 #ifndef _KERNEL
37 #define	bcopy(a, b, c)	(void) memmove(b, a, c)
38 #define	bcmp		memcmp
39 #define	bzero(a, c)	(void) memset(a, '\0', c)
40 #else	/* _KERNEL */
41 #define	malloc		bkmem_alloc
42 #endif	/* _KERNEL */
43 
44 #define	VERIFY_HASH_REALLOC
45 
46 static int
47 BCMP(void *str1, void *str2, int len)
48 {
49 	return (bcmp((char *)str1, (char *)str2, len));
50 }
51 
52 static int
53 HASH(void *datap, int datalen, int hsz)
54 {
55 	char	*cp;
56 	char	*np;
57 	int	hv = 0;
58 
59 	/* determine starting and ending positions */
60 
61 	cp = (char *)datap;
62 	np =  ((char *)cp + datalen);
63 
64 	/* compute hash over all characters from start to end */
65 
66 	while (cp != np) {
67 		hv += ((int)*cp++);
68 	}
69 
70 	/* return computed hash */
71 
72 	return (hv % hsz);
73 }
74 
75 int
76 init_cache(Cache **cp, int hsz, int bsz,
77 	    int (*hfunc)(void *, int, int), int (*cfunc)(void *, void *, int))
78 {
79 	if ((*cp = (Cache *) malloc(sizeof (**cp))) == NULL) {
80 		(void) fprintf(stderr, pkg_gt("malloc(Cache **cp)"));
81 		return (-1);
82 	}
83 	if (((*cp)->bp =
84 	    (Bucket *) malloc(sizeof (*(*cp)->bp) * hsz)) == NULL) {
85 		(void) fprintf(stderr, pkg_gt("malloc(Bucket cp->bp)"));
86 		return (-1);
87 	}
88 
89 	(*cp)->hsz = hsz;
90 	(*cp)->bsz = bsz;
91 
92 	bzero((*cp)->bp, sizeof (*(*cp)->bp) * hsz);
93 
94 	if (hfunc != (int (*)()) NULL) {
95 		(*cp)->hfunc = hfunc;
96 	} else {
97 		(*cp)->hfunc = HASH;
98 	}
99 
100 	if (cfunc != (int (*)()) NULL) {
101 		(*cp)->cfunc = cfunc;
102 	} else {
103 		(*cp)->cfunc = BCMP;
104 	}
105 	return (0);
106 }
107 
108 int
109 add_cache(Cache *cp, Item *itemp)
110 {
111 	Bucket *bp;
112 	Item **titempp;
113 
114 	/*
115 	 * If cp is NULL, then init_cache() wasn't called. Quietly return the
116 	 * error code and let the caller deal with it.
117 	 */
118 	if (cp == NULL)
119 		return (-1);
120 
121 	bp = &cp->bp[(*cp->hfunc)(itemp->key, itemp->keyl, cp->hsz)];
122 	if (bp->nent >= bp->nalloc) {
123 		if (bp->nalloc == 0) {
124 			bp->itempp =
125 			    (Item **) malloc(sizeof (*bp->itempp) * cp->bsz);
126 		} else {
127 #ifdef	VERIFY_HASH_REALLOC
128 			(void) fprintf(stderr,
129 			    pkg_gt("realloc(%d) bucket=%d\n"),
130 			    bp->nalloc + cp->bsz,
131 			    (*cp->hfunc)(itemp->key, itemp->keyl, cp->hsz));
132 #endif	/* VERIFY_HASH_REALLOC */
133 			if ((titempp =
134 			    (Item **) malloc(sizeof (*bp->itempp) *
135 			    (bp->nalloc + cp->bsz))) != NULL) {
136 				bcopy((char *)bp->itempp, (char *)titempp,
137 				    (sizeof (*bp->itempp) * bp->nalloc));
138 #ifdef _KERNEL
139 				bkmem_free(bp->itempp,
140 					(sizeof (*bp->itempp) * bp->nalloc));
141 #else	/* !_KERNEL */
142 				free(bp->itempp);
143 #endif	/* _KERNEL */
144 				bp->itempp = titempp;
145 			} else
146 				bp->itempp = NULL;
147 		}
148 		if (bp->itempp == NULL) {
149 			(void) fprintf(stderr,
150 			    pkg_gt("add_cache(): out of memory\n"));
151 			return (-1);
152 		}
153 		bp->nalloc += cp->bsz;
154 	}
155 	bp->itempp[bp->nent] = itemp;
156 	bp->nent++;
157 	return (0);
158 }
159 
160 Item *
161 lookup_cache(Cache *cp, void *datap, int datalen)
162 {
163 	int	i;
164 	Bucket *bp;
165 
166 	/*
167 	 * If cp is NULL, then init_cache() wasn't called. Quietly return the
168 	 * error code and let the caller deal with it.
169 	 */
170 	if (cp == NULL) {
171 	    return (Null_Item);
172 	}
173 
174 	bp = &cp->bp[(*cp->hfunc)(datap, datalen, cp->hsz)];
175 
176 	for (i = 0; i < bp->nent; i++) {
177 		if (!(*cp->cfunc)((void *)bp->itempp[i]->key, datap, datalen)) {
178 			return (bp->itempp[i]);
179 		}
180 	}
181 	return (Null_Item);
182 }
183