summaryrefslogtreecommitdiff
path: root/ecp/src/htable/hashtable.c
diff options
context:
space:
mode:
Diffstat (limited to 'ecp/src/htable/hashtable.c')
-rwxr-xr-xecp/src/htable/hashtable.c313
1 files changed, 0 insertions, 313 deletions
diff --git a/ecp/src/htable/hashtable.c b/ecp/src/htable/hashtable.c
deleted file mode 100755
index 36c8a6d..0000000
--- a/ecp/src/htable/hashtable.c
+++ /dev/null
@@ -1,313 +0,0 @@
-/* Copyright (C) 2004 Christopher Clark <firstname.lastname@cl.cam.ac.uk> */
-
-#include "hashtable.h"
-#include "hashtable_private.h"
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <math.h>
-
-#define MAX_LOAD_FACTOR 0.65F
-
-/*****************************************************************************/
-struct hashtable *
-hashtable_create(unsigned int minsize,
- unsigned int (*hashf) (void*),
- int (*eqf) (void*,void*))
-{
- struct hashtable *h;
- struct entry **t;
- unsigned int size;
- size = hashtable_prime_size(minsize);
- if (0 == size) return NULL;
- h = (struct hashtable *)malloc(sizeof(struct hashtable));
- if (NULL == h) return NULL; /*oom*/
- t = (struct entry **)malloc(sizeof(struct entry*) * size);
- if (NULL == t) { free(h); return NULL; } /*oom*/
- hashtable_create_static(h,t,size,hashf,eqf);
- return h;
-}
-
-/*****************************************************************************/
-void
-hashtable_create_static(struct hashtable *h, struct entry **t,
- unsigned int size,
- unsigned int (*hashf) (void*),
- int (*eqf) (void*,void*))
-{
- memset(t, 0, size * sizeof(struct entry *));
- h->table = t;
- h->tablelength = size;
- h->entrycount = 0;
- h->hashfn = hashf;
- h->eqfn = eqf;
- h->loadlimit = (unsigned int) ceil(size * MAX_LOAD_FACTOR);
-}
-
-unsigned int
-hashtable_prime_size(unsigned int minsize)
-{
- /*
- Credit for primes table: Aaron Krowne
- http://br.endernet.org/~akrowne/
- http://planetmath.org/encyclopedia/GoodHashTablePrimes.html
- */
- const unsigned int primes[] = {
- 53, 97, 193, 389,
- 769, 1543, 3079, 6151,
- 12289, 24593, 49157, 98317,
- 196613, 393241, 786433, 1572869,
- 3145739, 6291469, 12582917, 25165843,
- 50331653, 100663319, 201326611, 402653189,
- 805306457, 1610612741
- };
- const unsigned int prime_table_length = sizeof(primes)/sizeof(primes[0]);
- unsigned int pindex, size = 0;
- /* Check requested hashtable isn't too large */
- if (minsize > (1u << 30)) return 0;
- /* Enforce size as prime */
- for (pindex=0; pindex < prime_table_length; pindex++) {
- if (primes[pindex] >= minsize) { size = primes[pindex]; break; }
- }
- return size;
-}
-
-/*****************************************************************************/
-/* key - return the key of the (key,value) pair from hash table entry */
-/* value - return the value of the (key,value) pair from hash table entry */
-
-void *
-hashtable_entry_key(struct entry *e)
-{ return e->k; }
-
-void *
-hashtable_entry_value(struct entry *e)
-{ return e->v; }
-
-/*****************************************************************************/
-unsigned int
-hashtable_hash(struct hashtable *h, void *k)
-{
- return h->hashfn(k);
-}
-
-/*****************************************************************************/
-static int
-hashtable_expand(struct hashtable *h)
-{
- /* Double the size of the table to accomodate more entries */
- struct entry **newtable;
- struct entry *e;
- struct entry **pE;
- unsigned int newsize, i, index;
- newsize = hashtable_prime_size(h->tablelength + 1);
- /* Check we're not hitting max capacity */
- if (0 == newsize) return 0;
-
- newtable = (struct entry **)malloc(sizeof(struct entry*) * newsize);
- if (NULL != newtable)
- {
- memset(newtable, 0, newsize * sizeof(struct entry *));
- /* This algorithm is not 'stable'. ie. it reverses the list
- * when it transfers entries between the tables */
- for (i = 0; i < h->tablelength; i++) {
- while (NULL != (e = h->table[i])) {
- h->table[i] = e->next;
- index = indexFor(newsize,e->h);
- e->next = newtable[index];
- newtable[index] = e;
- }
- }
- free(h->table);
- h->table = newtable;
- }
- /* Plan B: realloc instead */
- else
- {
- newtable = (struct entry **)
- realloc(h->table, newsize * sizeof(struct entry *));
- if (NULL == newtable) return 0;
- h->table = newtable;
- memset(newtable[h->tablelength], 0, newsize - h->tablelength);
- for (i = 0; i < h->tablelength; i++) {
- for (pE = &(newtable[i]), e = *pE; e != NULL; e = *pE) {
- index = indexFor(newsize,e->h);
- if (index == i)
- {
- pE = &(e->next);
- }
- else
- {
- *pE = e->next;
- e->next = newtable[index];
- newtable[index] = e;
- }
- }
- }
- }
- h->tablelength = newsize;
- h->loadlimit = (unsigned int) ceil(newsize * MAX_LOAD_FACTOR);
- return -1;
-}
-
-/*****************************************************************************/
-unsigned int
-hashtable_count(struct hashtable *h)
-{
- return h->entrycount;
-}
-
-/*****************************************************************************/
-int
-hashtable_insert(struct hashtable *h, void *k, void *v)
-{
- struct entry *e;
- if (++(h->entrycount) > h->loadlimit)
- {
- /* Ignore the return value. If expand fails, we should
- * still try cramming just this value into the existing table
- * -- we may not have memory for a larger table, but one more
- * element may be ok. Next time we insert, we'll try expanding again.*/
- hashtable_expand(h);
- }
- e = (struct entry *)malloc(sizeof(struct entry));
- if (NULL == e) { --(h->entrycount); return 0; } /*oom*/
- hashtable_insert_static(h,e,k,v);
- return -1;
-}
-
-void
-hashtable_insert_static(struct hashtable *h, struct entry *e, void *k, void *v)
-{
- /* This method allows duplicate keys - but they shouldn't be used */
- unsigned int index;
- e->h = hashtable_hash(h,k);
- index = indexFor(h->tablelength,e->h);
- e->k = k;
- e->v = v;
- e->next = h->table[index];
- h->table[index] = e;
-}
-
-/*****************************************************************************/
-void * /* returns value associated with key */
-hashtable_search(struct hashtable *h, void *k)
-{
- struct entry *e;
- unsigned int hashvalue, index;
- hashvalue = hashtable_hash(h,k);
- index = indexFor(h->tablelength,hashvalue);
- e = h->table[index];
- while (NULL != e)
- {
- /* Check hash value to short circuit heavier comparison */
- if ((hashvalue == e->h) && (h->eqfn(k, e->k))) return e->v;
- e = e->next;
- }
- return NULL;
-}
-
-/*****************************************************************************/
-void * /* returns value associated with key */
-hashtable_remove(struct hashtable *h, void *k)
-{
- /* TODO: consider compacting the table when the load factor drops enough,
- * or provide a 'compact' method. */
-
- struct entry *e;
- void *v;
- e = hashtable_remove_static(h,k);
- if (NULL == e) return NULL;
- v = e->v;
- freekey(e->k);
- free(e);
- return v;
-}
-
-struct entry * /* returns hash table entry associated with key */
-hashtable_remove_static(struct hashtable *h, void *k)
-{
- struct entry *e;
- struct entry **pE;
- unsigned int hashvalue, index;
- hashvalue = hashtable_hash(h,k);
- index = indexFor(h->tablelength,hashvalue);
- pE = &(h->table[index]);
- e = *pE;
- while (NULL != e)
- {
- /* Check hash value to short circuit heavier comparison */
- if ((hashvalue == e->h) && (h->eqfn(k, e->k)))
- {
- *pE = e->next;
- h->entrycount--;
- return e;
- }
- pE = &(e->next);
- e = e->next;
- }
- return NULL;
-}
-
-/*****************************************************************************/
-/* destroy */
-void
-hashtable_destroy(struct hashtable *h, int free_values)
-{
- unsigned int i;
- struct entry *e, *f;
- struct entry **table = h->table;
- if (free_values)
- {
- for (i = 0; i < h->tablelength; i++)
- {
- e = table[i];
- while (NULL != e)
- { f = e; e = e->next; freekey(f->k); free(f->v); free(f); }
- }
- }
- else
- {
- for (i = 0; i < h->tablelength; i++)
- {
- e = table[i];
- while (NULL != e)
- { f = e; e = e->next; freekey(f->k); free(f); }
- }
- }
- free(h->table);
- free(h);
-}
-
-/*
- * Copyright (c) 2002, Christopher Clark
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * * Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- *
- * * Neither the name of the original author; nor the names of any contributors
- * may be used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
- * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
- * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
- * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
- * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-*/
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-10 14:38:05 +0000