/* * Portions Copyright (C) 2004 Internet Systems Consortium, Inc. ("ISC") * Portions Copyright (C) 2001 Internet Software Consortium. * Portions Copyright (C) 2001 Nominum, Inc. * * Permission to use, copy, modify, and 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. */ /* $ISC: symtab.c,v 1.3.12.3 2004/03/08 09:05:04 marka Exp $ */ #include #include #include #include #include #include #include #include #include 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; isc_boolean_t case_sensitive; }; isc_result_t isccc_symtab_create(unsigned int size, isccc_symtabundefaction_t undefine_action, void *undefine_arg, isc_boolean_t 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 inline 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; 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); *symtabp = NULL; } static inline unsigned int hash(const char *key, isc_boolean_t 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); } } }