1 /*- 2 * Copyright (c) 2003-2008 Joseph Koshy 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/types.h> 31 #include <sys/cpuset.h> 32 #include <sys/param.h> 33 #include <sys/stat.h> 34 #include <sys/pmc.h> 35 36 #include <assert.h> 37 #include <err.h> 38 #include <errno.h> 39 #include <pmc.h> 40 #include <pmclog.h> 41 #include <stdio.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <sysexits.h> 45 46 #include "libpmcstat.h" 47 48 static LIST_HEAD(,pmcstat_string) pmcstat_string_hash[PMCSTAT_NHASH]; 49 50 /* 51 * Intern a copy of string 's', and return a pointer to the 52 * interned structure. 53 */ 54 55 pmcstat_interned_string 56 pmcstat_string_intern(const char *s) 57 { 58 struct pmcstat_string *ps; 59 const struct pmcstat_string *cps; 60 int hash, len; 61 62 if ((cps = pmcstat_string_lookup(s)) != NULL) 63 return (cps); 64 65 hash = pmcstat_string_compute_hash(s); 66 len = strlen(s); 67 68 if ((ps = malloc(sizeof(*ps))) == NULL) 69 err(EX_OSERR, "ERROR: Could not intern string"); 70 ps->ps_len = len; 71 ps->ps_hash = hash; 72 ps->ps_string = strdup(s); 73 LIST_INSERT_HEAD(&pmcstat_string_hash[hash], ps, ps_next); 74 return ((pmcstat_interned_string) ps); 75 } 76 77 const char * 78 pmcstat_string_unintern(pmcstat_interned_string str) 79 { 80 const char *s; 81 82 s = ((const struct pmcstat_string *) str)->ps_string; 83 return (s); 84 } 85 86 /* 87 * Compute a 'hash' value for a string. 88 */ 89 90 int 91 pmcstat_string_compute_hash(const char *s) 92 { 93 unsigned hash; 94 95 for (hash = 2166136261; *s; s++) 96 hash = (hash ^ *s) * 16777619; 97 98 return (hash & PMCSTAT_HASH_MASK); 99 } 100 101 pmcstat_interned_string 102 pmcstat_string_lookup(const char *s) 103 { 104 struct pmcstat_string *ps; 105 int hash, len; 106 107 hash = pmcstat_string_compute_hash(s); 108 len = strlen(s); 109 110 LIST_FOREACH(ps, &pmcstat_string_hash[hash], ps_next) 111 if (ps->ps_len == len && ps->ps_hash == hash && 112 strcmp(ps->ps_string, s) == 0) 113 return (ps); 114 return (NULL); 115 } 116 117 int 118 pmcstat_string_lookup_hash(pmcstat_interned_string s) 119 { 120 const struct pmcstat_string *ps; 121 122 ps = (const struct pmcstat_string *) s; 123 return (ps->ps_hash); 124 } 125 126 /* 127 * Destroy the string table, free'ing up space. 128 */ 129 130 void 131 pmcstat_string_shutdown(void) 132 { 133 int i; 134 struct pmcstat_string *ps, *pstmp; 135 136 for (i = 0; i < PMCSTAT_NHASH; i++) 137 LIST_FOREACH_SAFE(ps, &pmcstat_string_hash[i], ps_next, 138 pstmp) { 139 LIST_REMOVE(ps, ps_next); 140 free(ps->ps_string); 141 free(ps); 142 } 143 } 144 145 /* 146 * Initialize the string interning facility. 147 */ 148 149 void 150 pmcstat_string_initialize(void) 151 { 152 int i; 153 154 for (i = 0; i < PMCSTAT_NHASH; i++) 155 LIST_INIT(&pmcstat_string_hash[i]); 156 } 157