diff options
Diffstat (limited to 'ecp/src/htable/hashtable.c')
| -rwxr-xr-x | ecp/src/htable/hashtable.c | 222 |
1 files changed, 130 insertions, 92 deletions
diff --git a/ecp/src/htable/hashtable.c b/ecp/src/htable/hashtable.c index de15827..1891f1b 100755 --- a/ecp/src/htable/hashtable.c +++ b/ecp/src/htable/hashtable.c @@ -2,80 +2,93 @@ #include "hashtable.h" #include "hashtable_private.h" +#include <stdlib.h> #include <stdio.h> #include <string.h> #include <math.h> -/* -Credit for primes table: Aaron Krowne - http://br.endernet.org/~akrowne/ - http://planetmath.org/encyclopedia/GoodHashTablePrimes.html -*/ -static 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]); -const float max_load_factor = 0.65; +#define MAX_LOAD_FACTOR 0.65F /*****************************************************************************/ struct hashtable * -create_hashtable(unsigned int minsize, - unsigned int (*hash_fn) (void*), - int (*eq_fn) (void*,void*), - void *(*malloc_fn) (size_t), - void *(*realloc_fn) (void*,size_t), - void (*free_fn) (void*)) +hashtable_create(unsigned int minsize, + unsigned int (*hashf) (void*), + int (*eqf) (void*,void*)) { - struct hashtable *h = NULL; - unsigned int pindex, size = primes[0]; - - /* Check requested hashtable isn't too large */ - if (minsize > (1u << 30)) return NULL; + 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); +} - malloc_fn = malloc_fn ? malloc_fn : malloc; - realloc_fn = realloc_fn ? realloc_fn : realloc; - free_fn = free_fn ? free_fn : free; - h = malloc_fn(sizeof(struct hashtable)); - if (NULL == h) return NULL; - memset(h, 0, sizeof(struct hashtable)); - +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; } + if (primes[pindex] >= minsize) { size = primes[pindex]; break; } } - h->fn_malloc = malloc_fn; - h->fn_realloc = realloc_fn; - h->fn_free = free_fn; - h->tablelength = size; - h->primeindex = pindex; - h->entrycount = 0; - h->fn_hash = hash_fn; - h->fn_eq = eq_fn; - h->loadlimit = (unsigned int) ceil(size * max_load_factor); - h->table = malloc_fn(sizeof(struct entry *) * size); - if (NULL == h->table) { free_fn(h); return NULL; } /*oom*/ - memset(h->table, 0, size * sizeof(struct entry *)); - return h; + 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) { - /* Aim to protect against poor hash functions by adding logic here - * - logic taken from java 1.4 hashtable source */ - unsigned int i = h->fn_hash(k); - i += ~(i << 9); - i ^= ((i >> 14) | (i << 18)); /* >>> */ - i += (i << 4); - i ^= ((i >> 10) | (i << 22)); /* >>> */ - return i; + return h->hashfn(k); } /*****************************************************************************/ @@ -87,11 +100,11 @@ hashtable_expand(struct hashtable *h) 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 (h->primeindex == (prime_table_length - 1)) return 0; - newsize = primes[++(h->primeindex)]; + if (0 == newsize) return 0; - newtable = h->fn_malloc(sizeof(struct entry *) * newsize); + newtable = (struct entry **)malloc(sizeof(struct entry*) * newsize); if (NULL != newtable) { memset(newtable, 0, newsize * sizeof(struct entry *)); @@ -105,14 +118,15 @@ hashtable_expand(struct hashtable *h) newtable[index] = e; } } - h->fn_free(h->table); + free(h->table); h->table = newtable; } /* Plan B: realloc instead */ - else + else { - newtable = h->fn_realloc(h->table, newsize * sizeof(struct entry *)); - if (NULL == newtable) { (h->primeindex)--; return 0; } + 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++) { @@ -132,7 +146,7 @@ hashtable_expand(struct hashtable *h) } } h->tablelength = newsize; - h->loadlimit = (unsigned int) ceil(newsize * max_load_factor); + h->loadlimit = (unsigned int) ceil(newsize * MAX_LOAD_FACTOR); return -1; } @@ -147,8 +161,6 @@ hashtable_count(struct hashtable *h) int hashtable_insert(struct hashtable *h, void *k, void *v) { - /* This method allows duplicate keys - but they shouldn't be used */ - unsigned int index; struct entry *e; if (++(h->entrycount) > h->loadlimit) { @@ -158,15 +170,23 @@ hashtable_insert(struct hashtable *h, void *k, void *v) * element may be ok. Next time we insert, we'll try expanding again.*/ hashtable_expand(h); } - e = h->fn_malloc(sizeof(struct entry)); + 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; - return -1; } /*****************************************************************************/ @@ -181,24 +201,34 @@ hashtable_search(struct hashtable *h, void *k) while (NULL != e) { /* Check hash value to short circuit heavier comparison */ - if ((hashvalue == e->h) && (h->fn_eq(k, e->k))) return e->v; + if ((hashvalue == e->h) && (h->eqfn(k, e->k))) return e->v; e = e->next; } return NULL; } /*****************************************************************************/ -void * /* returns value associated with key --- modified by majstor */ +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; - struct entry **pE; void *v; - unsigned int hashvalue, index; + e = hashtable_remove_static(h,k); + 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]); @@ -206,14 +236,11 @@ hashtable_remove(struct hashtable *h, void *k) while (NULL != e) { /* Check hash value to short circuit heavier comparison */ - if ((hashvalue == e->h) && (h->fn_eq(k, e->k))) + if ((hashvalue == e->h) && (h->eqfn(k, e->k))) { *pE = e->next; h->entrycount--; - v = e->v; - if (h->fn_free_k) h->fn_free_k(e->k); - h->fn_free(e); - return v; + return e->v; } pE = &(e->next); e = e->next; @@ -222,44 +249,55 @@ hashtable_remove(struct hashtable *h, void *k) } /*****************************************************************************/ -/* destroy --- modified by majstor */ +/* destroy */ void -hashtable_destroy(struct hashtable *h) +hashtable_destroy(struct hashtable *h, int free_values) { unsigned int i; struct entry *e, *f; struct entry **table = h->table; - - for (i = 0; i < h->tablelength; i++) + if (free_values) { - e = table[i]; - while (NULL != e) - { f = e; e = e->next; if (h->fn_free_k) h->fn_free_k(f->k); if (h->fn_free_v) h->fn_free_v(f->v); h->fn_free(f); } + 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); } + } } - h->fn_free(h->table); - h->fn_free(h); + 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 |