/* Fixed size hash table with internal linking. Copyright (C) 2000, 2001, 2002, 2004, 2005 Red Hat, Inc. This file is part of Red Hat elfutils. Written by Ulrich Drepper , 2000. Red Hat elfutils is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. Red Hat elfutils is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with Red Hat elfutils; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. In addition, as a special exception, Red Hat, Inc. gives You the additional right to link the code of Red Hat elfutils with code licensed under any Open Source Initiative certified open source license (http://www.opensource.org/licenses/index.php) which requires the distribution of source code with any binary distribution and to distribute linked combinations of the two. Non-GPL Code permitted under this exception must only link to the code of Red Hat elfutils through those well defined interfaces identified in the file named EXCEPTION found in the source code files (the "Approved Interfaces"). The files of Non-GPL Code may instantiate templates or use macros or inline functions from the Approved Interfaces without causing the resulting work to be covered by the GNU General Public License. Only Red Hat, Inc. may make changes or additions to the list of Approved Interfaces. Red Hat's grant of this exception is conditioned upon your not adding any new exceptions. If you wish to add a new Approved Interface or exception, please contact Red Hat. You must obey the GNU General Public License in all respects for all of the Red Hat elfutils code and other code used in conjunction with Red Hat elfutils except the Non-GPL Code covered by this exception. If you modify this file, you may extend this exception to your version of the file, but you are not obligated to do so. If you do not wish to provide this exception without modification, you must delete this exception statement from your version and license this file solely under the GPL without exception. Red Hat elfutils is an included package of the Open Invention Network. An included package of the Open Invention Network is a package for which Open Invention Network licensees cross-license their patents. No patent license is granted, either expressly or impliedly, by designation as an included package. Should you wish to participate in the Open Invention Network licensing program, please visit www.openinventionnetwork.com . */ #include #include #include #include #include #include #define CONCAT(t1,t2) __CONCAT (t1,t2) /* Before including this file the following macros must be defined: TYPE data type of the hash table entries HASHFCT name of the hashing function to use HASHTYPE type used for the hashing value COMPARE comparison function taking two pointers to TYPE objects CLASS can be defined to `static' to avoid exporting the functions PREFIX prefix to be used for function and data type names STORE_POINTER if defined the table stores a pointer and not an element of type TYPE INSERT_HASH if defined alternate insert function which takes a hash value is defined NO_FINI_FCT if defined the fini function is not defined */ /* Defined separately. */ extern size_t next_prime (size_t seed); /* Set default values. */ #ifndef HASHTYPE # define HASHTYPE size_t #endif #ifndef CLASS # define CLASS #endif #ifndef PREFIX # define PREFIX #endif /* The data structure. */ struct CONCAT(PREFIX,fshash) { size_t nslots; struct CONCAT(PREFIX,fshashent) { HASHTYPE hval; #ifdef STORE_POINTER # define ENTRYP(el) (el).entry TYPE *entry; #else # define ENTRYP(el) &(el).entry TYPE entry; #endif } table[0]; }; /* Constructor for the hashing table. */ CLASS struct CONCAT(PREFIX,fshash) * CONCAT(PREFIX,fshash_init) (size_t nelems) { struct CONCAT(PREFIX,fshash) *result; /* We choose a size for the hashing table 150% over the number of entries. This will guarantee short medium search lengths. */ const size_t max_size_t = ~((size_t) 0); if (nelems >= (max_size_t / 3) * 2) { errno = EINVAL; return NULL; } /* Adjust the size to be used for the hashing table. */ nelems = next_prime (MAX ((nelems * 3) / 2, 10)); /* Allocate the data structure for the result. */ result = (struct CONCAT(PREFIX,fshash) *) xcalloc (sizeof (struct CONCAT(PREFIX,fshash)) + (nelems + 1) * sizeof (struct CONCAT(PREFIX,fshashent)), 1); if (result == NULL) return NULL; result->nslots = nelems; return result; } #ifndef NO_FINI_FCT CLASS void CONCAT(PREFIX,fshash_fini) (struct CONCAT(PREFIX,fshash) *htab) { free (htab); } #endif static struct CONCAT(PREFIX,fshashent) * CONCAT(PREFIX,fshash_lookup) (struct CONCAT(PREFIX,fshash) *htab, HASHTYPE hval, TYPE *data) { size_t idx = 1 + hval % htab->nslots; if (htab->table[idx].hval != 0) { HASHTYPE hash; /* See whether this is the same entry. */ if (htab->table[idx].hval == hval && COMPARE (data, ENTRYP (htab->table[idx])) == 0) return &htab->table[idx]; /* Second hash function as suggested in [Knuth]. */ hash = 1 + hval % (htab->nslots - 2); do { if (idx <= hash) idx = htab->nslots + idx - hash; else idx -= hash; if (htab->table[idx].hval == hval && COMPARE (data, ENTRYP(htab->table[idx])) == 0) return &htab->table[idx]; } while (htab->table[idx].hval != 0); } return &htab->table[idx]; } CLASS int __attribute__ ((unused)) CONCAT(PREFIX,fshash_insert) (struct CONCAT(PREFIX,fshash) *htab, const char *str, size_t len __attribute__ ((unused)), TYPE *data) { HASHTYPE hval = HASHFCT (str, len ?: strlen (str)); struct CONCAT(PREFIX,fshashent) *slot; slot = CONCAT(PREFIX,fshash_lookup) (htab, hval, data); if (slot->hval != 0) /* We don't want to overwrite the old value. */ return -1; slot->hval = hval; #ifdef STORE_POINTER slot->entry = data; #else slot->entry = *data; #endif return 0; } #ifdef INSERT_HASH CLASS int __attribute__ ((unused)) CONCAT(PREFIX,fshash_insert_hash) (struct CONCAT(PREFIX,fshash) *htab, HASHTYPE hval, TYPE *data) { struct CONCAT(PREFIX,fshashent) *slot; slot = CONCAT(PREFIX,fshash_lookup) (htab, hval, data); if (slot->hval != 0) /* We don't want to overwrite the old value. */ return -1; slot->hval = hval; #ifdef STORE_POINTER slot->entry = data; #else slot->entry = *data; #endif return 0; } #endif CLASS int __attribute__ ((unused)) CONCAT(PREFIX,fshash_overwrite) (struct CONCAT(PREFIX,fshash) *htab, const char *str, size_t len __attribute__ ((unused)), TYPE *data) { HASHTYPE hval = HASHFCT (str, len ?: strlen (str)); struct CONCAT(PREFIX,fshashent) *slot; slot = CONCAT(PREFIX,fshash_lookup) (htab, hval, data); slot->hval = hval; #ifdef STORE_POINTER slot->entry = data; #else slot->entry = *data; #endif return 0; } CLASS const TYPE * CONCAT(PREFIX,fshash_find) (const struct CONCAT(PREFIX,fshash) *htab, const char *str, size_t len __attribute__ ((unused)), TYPE *data) { HASHTYPE hval = HASHFCT (str, len ?: strlen (str)); struct CONCAT(PREFIX,fshashent) *slot; slot = CONCAT(PREFIX,fshash_lookup) ((struct CONCAT(PREFIX,fshash) *) htab, hval, data); if (slot->hval == 0) /* Not found. */ return NULL; return ENTRYP(*slot); } /* Unset the macros we expect. */ #undef TYPE #undef HASHFCT #undef HASHTYPE #undef COMPARE #undef CLASS #undef PREFIX #undef INSERT_HASH #undef STORE_POINTER #undef NO_FINI_FCT