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-rw-r--r--lib/isccc/symtab.c293
1 files changed, 293 insertions, 0 deletions
diff --git a/lib/isccc/symtab.c b/lib/isccc/symtab.c
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+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0 AND ISC
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*! \file */
+
+#include <ctype.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+#include <isc/assertions.h>
+#include <isc/magic.h>
+#include <isc/string.h>
+
+#include <isccc/result.h>
+#include <isccc/symtab.h>
+#include <isccc/util.h>
+
+typedef struct elt {
+ char *key;
+ unsigned int type;
+ isccc_symvalue_t value;
+ ISC_LINK(struct elt) link;
+} elt_t;
+
+typedef ISC_LIST(elt_t) eltlist_t;
+
+#define SYMTAB_MAGIC ISC_MAGIC('S', 'y', 'm', 'T')
+#define VALID_SYMTAB(st) ISC_MAGIC_VALID(st, SYMTAB_MAGIC)
+
+struct isccc_symtab {
+ unsigned int magic;
+ unsigned int size;
+ eltlist_t *table;
+ isccc_symtabundefaction_t undefine_action;
+ void *undefine_arg;
+ bool case_sensitive;
+};
+
+isc_result_t
+isccc_symtab_create(unsigned int size,
+ isccc_symtabundefaction_t undefine_action,
+ void *undefine_arg, bool case_sensitive,
+ isccc_symtab_t **symtabp) {
+ isccc_symtab_t *symtab;
+ unsigned int i;
+
+ REQUIRE(symtabp != NULL && *symtabp == NULL);
+ REQUIRE(size > 0); /* Should be prime. */
+
+ symtab = malloc(sizeof(*symtab));
+ if (symtab == NULL) {
+ return (ISC_R_NOMEMORY);
+ }
+ symtab->table = malloc(size * sizeof(eltlist_t));
+ if (symtab->table == NULL) {
+ free(symtab);
+ return (ISC_R_NOMEMORY);
+ }
+ for (i = 0; i < size; i++) {
+ ISC_LIST_INIT(symtab->table[i]);
+ }
+ symtab->size = size;
+ symtab->undefine_action = undefine_action;
+ symtab->undefine_arg = undefine_arg;
+ symtab->case_sensitive = case_sensitive;
+ symtab->magic = SYMTAB_MAGIC;
+
+ *symtabp = symtab;
+
+ return (ISC_R_SUCCESS);
+}
+
+static void
+free_elt(isccc_symtab_t *symtab, unsigned int bucket, elt_t *elt) {
+ ISC_LIST_UNLINK(symtab->table[bucket], elt, link);
+ if (symtab->undefine_action != NULL) {
+ (symtab->undefine_action)(elt->key, elt->type, elt->value,
+ symtab->undefine_arg);
+ }
+ free(elt);
+}
+
+void
+isccc_symtab_destroy(isccc_symtab_t **symtabp) {
+ isccc_symtab_t *symtab;
+ unsigned int i;
+ elt_t *elt, *nelt;
+
+ REQUIRE(symtabp != NULL);
+ symtab = *symtabp;
+ *symtabp = NULL;
+ REQUIRE(VALID_SYMTAB(symtab));
+
+ for (i = 0; i < symtab->size; i++) {
+ for (elt = ISC_LIST_HEAD(symtab->table[i]); elt != NULL;
+ elt = nelt)
+ {
+ nelt = ISC_LIST_NEXT(elt, link);
+ free_elt(symtab, i, elt);
+ }
+ }
+ free(symtab->table);
+ symtab->magic = 0;
+ free(symtab);
+}
+
+static unsigned int
+hash(const char *key, bool case_sensitive) {
+ const char *s;
+ unsigned int h = 0;
+ unsigned int g;
+ int c;
+
+ /*
+ * P. J. Weinberger's hash function, adapted from p. 436 of
+ * _Compilers: Principles, Techniques, and Tools_, Aho, Sethi
+ * and Ullman, Addison-Wesley, 1986, ISBN 0-201-10088-6.
+ */
+
+ if (case_sensitive) {
+ for (s = key; *s != '\0'; s++) {
+ h = (h << 4) + *s;
+ if ((g = (h & 0xf0000000)) != 0) {
+ h = h ^ (g >> 24);
+ h = h ^ g;
+ }
+ }
+ } else {
+ for (s = key; *s != '\0'; s++) {
+ c = *s;
+ c = tolower((unsigned char)c);
+ h = (h << 4) + c;
+ if ((g = (h & 0xf0000000)) != 0) {
+ h = h ^ (g >> 24);
+ h = h ^ g;
+ }
+ }
+ }
+
+ return (h);
+}
+
+#define FIND(s, k, t, b, e) \
+ b = hash((k), (s)->case_sensitive) % (s)->size; \
+ if ((s)->case_sensitive) { \
+ for (e = ISC_LIST_HEAD((s)->table[b]); e != NULL; \
+ e = ISC_LIST_NEXT(e, link)) \
+ { \
+ if (((t) == 0 || e->type == (t)) && \
+ strcmp(e->key, (k)) == 0) \
+ break; \
+ } \
+ } else { \
+ for (e = ISC_LIST_HEAD((s)->table[b]); e != NULL; \
+ e = ISC_LIST_NEXT(e, link)) \
+ { \
+ if (((t) == 0 || e->type == (t)) && \
+ strcasecmp(e->key, (k)) == 0) \
+ break; \
+ } \
+ }
+
+isc_result_t
+isccc_symtab_lookup(isccc_symtab_t *symtab, const char *key, unsigned int type,
+ isccc_symvalue_t *value) {
+ unsigned int bucket;
+ elt_t *elt;
+
+ REQUIRE(VALID_SYMTAB(symtab));
+ REQUIRE(key != NULL);
+
+ FIND(symtab, key, type, bucket, elt);
+
+ if (elt == NULL) {
+ return (ISC_R_NOTFOUND);
+ }
+
+ if (value != NULL) {
+ *value = elt->value;
+ }
+
+ return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isccc_symtab_define(isccc_symtab_t *symtab, char *key, unsigned int type,
+ isccc_symvalue_t value, isccc_symexists_t exists_policy) {
+ unsigned int bucket;
+ elt_t *elt;
+
+ REQUIRE(VALID_SYMTAB(symtab));
+ REQUIRE(key != NULL);
+ REQUIRE(type != 0);
+
+ FIND(symtab, key, type, bucket, elt);
+
+ if (exists_policy != isccc_symexists_add && elt != NULL) {
+ if (exists_policy == isccc_symexists_reject) {
+ return (ISC_R_EXISTS);
+ }
+ INSIST(exists_policy == isccc_symexists_replace);
+ ISC_LIST_UNLINK(symtab->table[bucket], elt, link);
+ if (symtab->undefine_action != NULL) {
+ (symtab->undefine_action)(elt->key, elt->type,
+ elt->value,
+ symtab->undefine_arg);
+ }
+ } else {
+ elt = malloc(sizeof(*elt));
+ if (elt == NULL) {
+ return (ISC_R_NOMEMORY);
+ }
+ ISC_LINK_INIT(elt, link);
+ }
+
+ elt->key = key;
+ elt->type = type;
+ elt->value = value;
+
+ /*
+ * We prepend so that the most recent definition will be found.
+ */
+ ISC_LIST_PREPEND(symtab->table[bucket], elt, link);
+
+ return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isccc_symtab_undefine(isccc_symtab_t *symtab, const char *key,
+ unsigned int type) {
+ unsigned int bucket;
+ elt_t *elt;
+
+ REQUIRE(VALID_SYMTAB(symtab));
+ REQUIRE(key != NULL);
+
+ FIND(symtab, key, type, bucket, elt);
+
+ if (elt == NULL) {
+ return (ISC_R_NOTFOUND);
+ }
+
+ free_elt(symtab, bucket, elt);
+
+ return (ISC_R_SUCCESS);
+}
+
+void
+isccc_symtab_foreach(isccc_symtab_t *symtab, isccc_symtabforeachaction_t action,
+ void *arg) {
+ unsigned int i;
+ elt_t *elt, *nelt;
+
+ REQUIRE(VALID_SYMTAB(symtab));
+ REQUIRE(action != NULL);
+
+ for (i = 0; i < symtab->size; i++) {
+ for (elt = ISC_LIST_HEAD(symtab->table[i]); elt != NULL;
+ elt = nelt)
+ {
+ nelt = ISC_LIST_NEXT(elt, link);
+ if ((action)(elt->key, elt->type, elt->value, arg)) {
+ free_elt(symtab, i, elt);
+ }
+ }
+ }
+}
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