/* * Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC") * Copyright (C) 1996-2001 Internet Software Consortium. * * 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 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. */ /* $Id: symtab.c,v 1.30 2007/06/19 23:47:17 tbox Exp $ */ /*! \file */ #include #include #include #include #include #include #include typedef struct elt { char * key; unsigned int type; isc_symvalue_t value; LINK(struct elt) link; } elt_t; typedef 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 isc_symtab { /* Unlocked. */ unsigned int magic; isc_mem_t * mctx; unsigned int size; eltlist_t * table; isc_symtabaction_t undefine_action; void * undefine_arg; isc_boolean_t case_sensitive; }; isc_result_t isc_symtab_create(isc_mem_t *mctx, unsigned int size, isc_symtabaction_t undefine_action, void *undefine_arg, isc_boolean_t case_sensitive, isc_symtab_t **symtabp) { isc_symtab_t *symtab; unsigned int i; REQUIRE(mctx != NULL); REQUIRE(symtabp != NULL && *symtabp == NULL); REQUIRE(size > 0); /* Should be prime. */ symtab = (isc_symtab_t *)isc_mem_get(mctx, sizeof(*symtab)); if (symtab == NULL) return (ISC_R_NOMEMORY); symtab->table = (eltlist_t *)isc_mem_get(mctx, size * sizeof(eltlist_t)); if (symtab->table == NULL) { isc_mem_put(mctx, symtab, sizeof(*symtab)); return (ISC_R_NOMEMORY); } for (i = 0; i < size; i++) INIT_LIST(symtab->table[i]); symtab->mctx = mctx; 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); } void isc_symtab_destroy(isc_symtab_t **symtabp) { isc_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 = HEAD(symtab->table[i]); elt != NULL; elt = nelt) { nelt = NEXT(elt, link); if (symtab->undefine_action != NULL) (symtab->undefine_action)(elt->key, elt->type, elt->value, symtab->undefine_arg); isc_mem_put(symtab->mctx, elt, sizeof(*elt)); } } isc_mem_put(symtab->mctx, symtab->table, symtab->size * sizeof(eltlist_t)); symtab->magic = 0; isc_mem_put(symtab->mctx, symtab, sizeof(*symtab)); *symtabp = NULL; } static inline unsigned int hash(const char *key, isc_boolean_t case_sensitive) { const char *s; unsigned int h = 0; int c; /* * This hash function is similar to the one Ousterhout * uses in Tcl. */ if (case_sensitive) { for (s = key; *s != '\0'; s++) { h += (h << 3) + *s; } } else { for (s = key; *s != '\0'; s++) { c = *s; c = tolower((unsigned char)c); h += (h << 3) + c; } } return (h); } #define FIND(s, k, t, b, e) \ b = hash((k), (s)->case_sensitive) % (s)->size; \ if ((s)->case_sensitive) { \ for (e = HEAD((s)->table[b]); e != NULL; e = NEXT(e, link)) { \ if (((t) == 0 || e->type == (t)) && \ strcmp(e->key, (k)) == 0) \ break; \ } \ } else { \ for (e = HEAD((s)->table[b]); e != NULL; e = NEXT(e, link)) { \ if (((t) == 0 || e->type == (t)) && \ strcasecmp(e->key, (k)) == 0) \ break; \ } \ } isc_result_t isc_symtab_lookup(isc_symtab_t *symtab, const char *key, unsigned int type, isc_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 isc_symtab_define(isc_symtab_t *symtab, const char *key, unsigned int type, isc_symvalue_t value, isc_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 != isc_symexists_add && elt != NULL) { if (exists_policy == isc_symexists_reject) return (ISC_R_EXISTS); INSIST(exists_policy == isc_symexists_replace); 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 = (elt_t *)isc_mem_get(symtab->mctx, sizeof(*elt)); if (elt == NULL) return (ISC_R_NOMEMORY); ISC_LINK_INIT(elt, link); } /* * Though the "key" can be const coming in, it is not stored as const * so that the calling program can easily have writable access to * it in its undefine_action function. In the event that it *was* * truly const coming in and then the caller modified it anyway ... * well, don't do that! */ DE_CONST(key, elt->key); elt->type = type; elt->value = value; /* * We prepend so that the most recent definition will be found. */ PREPEND(symtab->table[bucket], elt, link); return (ISC_R_SUCCESS); } isc_result_t isc_symtab_undefine(isc_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); if (symtab->undefine_action != NULL) (symtab->undefine_action)(elt->key, elt->type, elt->value, symtab->undefine_arg); UNLINK(symtab->table[bucket], elt, link); isc_mem_put(symtab->mctx, elt, sizeof(*elt)); return (ISC_R_SUCCESS); }