1 /* $NetBSD: hash.c,v 1.8 2002/01/31 19:36:55 tv Exp $ */ 2 3 /* 4 * Copyright (c) 1994, 1995 Jochen Pohl 5 * All Rights Reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Jochen Pohl for 18 * The NetBSD Project. 19 * 4. The name of the author may not be used to endorse or promote products 20 * derived from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #include <sys/cdefs.h> 35 #if defined(__RCSID) && !defined(lint) 36 __RCSID("$NetBSD: hash.c,v 1.8 2002/01/31 19:36:55 tv Exp $"); 37 #endif 38 39 /* 40 * XXX Really need a generalized hash table package 41 */ 42 43 #include <limits.h> 44 #include <stddef.h> 45 #include <stdlib.h> 46 #include <string.h> 47 48 #include "lint2.h" 49 50 /* pointer to hash table, initialized in inithash() */ 51 static hte_t **htab; 52 53 static int hash(const char *); 54 55 /* 56 * Initialize hash table. 57 */ 58 void 59 _inithash(hte_t ***tablep) 60 { 61 62 if (tablep == NULL) 63 tablep = &htab; 64 65 *tablep = xcalloc(HSHSIZ2, sizeof (hte_t *)); 66 } 67 68 /* 69 * Compute hash value from a string. 70 */ 71 static int 72 hash(const char *s) 73 { 74 u_int v; 75 const u_char *us; 76 77 v = 0; 78 for (us = (const u_char *)s; *us != '\0'; us++) { 79 v = (v << sizeof (v)) + *us; 80 v ^= v >> (sizeof (v) * CHAR_BIT - sizeof (v)); 81 } 82 return (v % HSHSIZ2); 83 } 84 85 /* 86 * Look for a hash table entry. If no hash table entry for the 87 * given name exists and mknew is set, create a new one. 88 */ 89 hte_t * 90 _hsearch(hte_t **table, const char *s, int mknew) 91 { 92 int h; 93 hte_t *hte; 94 95 if (table == NULL) 96 table = htab; 97 98 h = hash(s); 99 for (hte = table[h]; hte != NULL; hte = hte->h_link) { 100 if (strcmp(hte->h_name, s) == 0) 101 break; 102 } 103 104 if (hte != NULL || !mknew) 105 return (hte); 106 107 /* create a new hte */ 108 hte = xmalloc(sizeof (hte_t)); 109 hte->h_name = xstrdup(s); 110 hte->h_used = 0; 111 hte->h_def = 0; 112 hte->h_static = 0; 113 hte->h_syms = NULL; 114 hte->h_lsym = &hte->h_syms; 115 hte->h_calls = NULL; 116 hte->h_lcall = &hte->h_calls; 117 hte->h_usyms = NULL; 118 hte->h_lusym = &hte->h_usyms; 119 hte->h_link = table[h]; 120 hte->h_hte = NULL; 121 table[h] = hte; 122 123 return (hte); 124 } 125 126 /* 127 * Call function f for each name in the hash table. 128 */ 129 void 130 _forall(hte_t **table, void (*f)(hte_t *)) 131 { 132 int i; 133 hte_t *hte; 134 135 if (table == NULL) 136 table = htab; 137 138 for (i = 0; i < HSHSIZ2; i++) { 139 for (hte = table[i]; hte != NULL; hte = hte->h_link) 140 (*f)(hte); 141 } 142 } 143 144 /* 145 * Free all contents of the hash table that this module allocated. 146 */ 147 void 148 _destroyhash(hte_t **table) 149 { 150 int i; 151 hte_t *hte, *nexthte; 152 153 if (table == NULL) 154 err(1, "_destroyhash called on main hash table"); 155 156 for (i = 0; i < HSHSIZ2; i++) { 157 for (hte = table[i]; hte != NULL; hte = nexthte) { 158 free((void *)hte->h_name); 159 nexthte = hte->h_link; 160 free(hte); 161 } 162 } 163 free(table); 164 } 165