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 #include <sys/types.h> 29 #include <sys/cpuset.h> 30 #include <sys/param.h> 31 #include <sys/stat.h> 32 #include <sys/pmc.h> 33 34 #include <assert.h> 35 #include <err.h> 36 #include <errno.h> 37 #include <pmc.h> 38 #include <pmclog.h> 39 #include <stdio.h> 40 #include <stdlib.h> 41 #include <string.h> 42 #include <sysexits.h> 43 44 #include "libpmcstat.h" 45 46 static LIST_HEAD(,pmcstat_string) pmcstat_string_hash[PMCSTAT_NHASH]; 47 48 /* 49 * Intern a copy of string 's', and return a pointer to the 50 * interned structure. 51 */ 52 53 pmcstat_interned_string 54 pmcstat_string_intern(const char *s) 55 { 56 struct pmcstat_string *ps; 57 const struct pmcstat_string *cps; 58 int hash, len; 59 60 if ((cps = pmcstat_string_lookup(s)) != NULL) 61 return (cps); 62 63 hash = pmcstat_string_compute_hash(s); 64 len = strlen(s); 65 66 if ((ps = malloc(sizeof(*ps))) == NULL) 67 err(EX_OSERR, "ERROR: Could not intern string"); 68 ps->ps_len = len; 69 ps->ps_hash = hash; 70 ps->ps_string = strdup(s); 71 LIST_INSERT_HEAD(&pmcstat_string_hash[hash], ps, ps_next); 72 return ((pmcstat_interned_string) ps); 73 } 74 75 const char * 76 pmcstat_string_unintern(pmcstat_interned_string str) 77 { 78 const char *s; 79 80 s = ((const struct pmcstat_string *) str)->ps_string; 81 return (s); 82 } 83 84 /* 85 * Compute a 'hash' value for a string. 86 */ 87 88 int 89 pmcstat_string_compute_hash(const char *s) 90 { 91 unsigned hash; 92 93 for (hash = 2166136261; *s; s++) 94 hash = (hash ^ *s) * 16777619; 95 96 return (hash & PMCSTAT_HASH_MASK); 97 } 98 99 pmcstat_interned_string 100 pmcstat_string_lookup(const char *s) 101 { 102 struct pmcstat_string *ps; 103 int hash, len; 104 105 hash = pmcstat_string_compute_hash(s); 106 len = strlen(s); 107 108 LIST_FOREACH(ps, &pmcstat_string_hash[hash], ps_next) 109 if (ps->ps_len == len && ps->ps_hash == hash && 110 strcmp(ps->ps_string, s) == 0) 111 return (ps); 112 return (NULL); 113 } 114 115 int 116 pmcstat_string_lookup_hash(pmcstat_interned_string s) 117 { 118 const struct pmcstat_string *ps; 119 120 ps = (const struct pmcstat_string *) s; 121 return (ps->ps_hash); 122 } 123 124 /* 125 * Destroy the string table, free'ing up space. 126 */ 127 128 void 129 pmcstat_string_shutdown(void) 130 { 131 int i; 132 struct pmcstat_string *ps, *pstmp; 133 134 for (i = 0; i < PMCSTAT_NHASH; i++) 135 LIST_FOREACH_SAFE(ps, &pmcstat_string_hash[i], ps_next, 136 pstmp) { 137 LIST_REMOVE(ps, ps_next); 138 free(ps->ps_string); 139 free(ps); 140 } 141 } 142 143 /* 144 * Initialize the string interning facility. 145 */ 146 147 void 148 pmcstat_string_initialize(void) 149 { 150 int i; 151 152 for (i = 0; i < PMCSTAT_NHASH; i++) 153 LIST_INIT(&pmcstat_string_hash[i]); 154 } 155