WebSVN – HelenOS-historic – Diff – /uspace/trunk/libadt/generic/hash_table.c


/*
 * Copyright (C) 2006 Jakub Jermar
 * 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */
 
/*
 * This is an implementation of generic chained hash table.
 */
 
#include <hash_table.h>
#include <list.h>
#include <unistd.h>
#include <malloc.h>
#include <assert.h>
#include <stdio.h>
#include <string.h>
 
/** Create chained hash table.
 *
 * @param h Hash table structure. Will be initialized by this call.
 * @param m Number of slots in the hash table.
 * @param max_keys Maximal number of keys needed to identify an item.
 * @param op Hash table operations structure.
 * @return true on success
 */
int hash_table_create(hash_table_t *h, hash_count_t m, hash_count_t max_keys, hash_table_operations_t *op)
{
    hash_count_t i;
 
    assert(h);
    assert(op && op->hash && op->compare);
    assert(max_keys > 0);
   
    h->entry = malloc(m * sizeof(link_t));
    if (!h->entry) {
        printf("cannot allocate memory for hash table\n");
        return false;
    }
    memset((void *) h->entry, 0,  m * sizeof(link_t));
   
    for (i = 0; i < m; i++)
        list_initialize(&h->entry[i]);
   
    h->entries = m;
    h->max_keys = max_keys;
    h->op = op;
    return true;
}
 
/** Insert item into hash table.
 *
 * @param h Hash table.
 * @param hey Array of all keys necessary to compute hash index.
 * @param item Item to be inserted into the hash table.
 */
void hash_table_insert(hash_table_t *h, unsigned long key[], link_t *item)
{
    hash_index_t chain;
 
    assert(item);
    assert(h && h->op && h->op->hash && h->op->compare);
 
    chain = h->op->hash(key);
    assert(chain < h->entries);
   
    list_append(item, &h->entry[chain]);
}
 
/** Search hash table for an item matching keys.
 *
 * @param h Hash table.
 * @param key Array of all keys needed to compute hash index.
 *
 * @return Matching item on success, NULL if there is no such item.
 */
link_t *hash_table_find(hash_table_t *h, unsigned long key[])
{
    link_t *cur;
    hash_index_t chain;
 
    assert(h && h->op && h->op->hash && h->op->compare);
 
    chain = h->op->hash(key);
    assert(chain < h->entries);
   
    /*
     * The hash table is not redundant.
     * Check if the keys are not in place already.
     */
    for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) {
        if (h->op->compare(key, h->max_keys, cur)) {
            /*
             * The entry is there.
             */
            return cur;
        }
    }
   
    return NULL;
}
 
/** Remove all matching items from hash table.
 *
 * For each removed item, h->remove_callback() is called.
 *
 * @param h Hash table.
 * @param key Array of keys that will be compared against items of the hash table.
 * @param keys Number of keys in the 'key' array.
 */
void hash_table_remove(hash_table_t *h, unsigned long key[], hash_count_t keys)
{
    hash_index_t chain;
    link_t *cur;
 
    assert(h && h->op && h->op->hash && h->op->compare && h->op->remove_callback);
    assert(keys <= h->max_keys);
   
    if (keys == h->max_keys) {
 
        /*
         * All keys are known, hash_table_find() can be used to find the entry.
         */
   
        cur = hash_table_find(h, key);
        if (cur) {
            list_remove(cur);
            h->op->remove_callback(cur);
        }
        return;
    }
   
    /*
     * Fewer keys were passed.
     * Any partially matching entries are to be removed.
     */
    for (chain = 0; chain < h->entries; chain++) {
        for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) {
            if (h->op->compare(key, keys, cur)) {
                link_t *hlp;
               
                hlp = cur;
                cur = cur->prev;
               
                list_remove(hlp);
                h->op->remove_callback(hlp);
               
                continue;
            }
        }
    }
}
 

Rev 997	Rev 1202
1	/*	1	/*
2	* Copyright (C) 2006 Jakub Jermar	2	* Copyright (C) 2006 Jakub Jermar
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/*	29	/*
30	* This is an implementation of generic chained hash table.	30	* This is an implementation of generic chained hash table.
31	*/	31	*/
32		32
33	#include <hash_table.h>	33	#include <hash_table.h>
34	#include <list.h>	34	#include <list.h>
35	#include <unistd.h>	35	#include <unistd.h>
36	#include <malloc.h>	36	#include <malloc.h>
37	#include <assert.h>	37	#include <assert.h>
38	#include <stdio.h>	38	#include <stdio.h>
39	#include <string.h>	39	#include <string.h>
40		40
41	/** Create chained hash table.	41	/** Create chained hash table.
42	*	42	*
43	* @param h Hash table structure. Will be initialized by this call.	43	* @param h Hash table structure. Will be initialized by this call.
44	* @param m Number of slots in the hash table.	44	* @param m Number of slots in the hash table.
45	* @param max_keys Maximal number of keys needed to identify an item.	45	* @param max_keys Maximal number of keys needed to identify an item.
46	* @param op Hash table operations structure.	46	* @param op Hash table operations structure.
47	* @return true on success	47	* @return true on success
48	*/	48	*/
49	int hash_table_create(hash_table_t h, hash_count_t m, hash_count_t max_keys, hash_table_operations_t op)	49	int hash_table_create(hash_table_t h, hash_count_t m, hash_count_t max_keys, hash_table_operations_t op)
50	{	50	{
51	hash_count_t i;	51	hash_count_t i;
52		52
53	assert(h);	53	assert(h);
54	assert(op && op->hash && op->compare);	54	assert(op && op->hash && op->compare);
55	assert(max_keys > 0);	55	assert(max_keys > 0);
56		56
57	h->entry = malloc(m * sizeof(link_t *));	57	h->entry = malloc(m * sizeof(link_t));
58	if (!h->entry) {	58	if (!h->entry) {
59	printf("cannot allocate memory for hash table\n");	59	printf("cannot allocate memory for hash table\n");
60	return false;	60	return false;
61	}	61	}
62	memset((void ) h->entry, 0, m sizeof(link_t *));	62	memset((void ) h->entry, 0, m sizeof(link_t));
63		63
64	for (i = 0; i < m; i++)	64	for (i = 0; i < m; i++)
65	list_initialize(&h->entry[i]);	65	list_initialize(&h->entry[i]);
66		66
67	h->entries = m;	67	h->entries = m;
68	h->max_keys = max_keys;	68	h->max_keys = max_keys;
69	h->op = op;	69	h->op = op;
70	return true;	70	return true;
71	}	71	}
72		72
73	/** Insert item into hash table.	73	/** Insert item into hash table.
74	*	74	*
75	* @param h Hash table.	75	* @param h Hash table.
76	* @param hey Array of all keys necessary to compute hash index.	76	* @param hey Array of all keys necessary to compute hash index.
77	* @param item Item to be inserted into the hash table.	77	* @param item Item to be inserted into the hash table.
78	*/	78	*/
79	void hash_table_insert(hash_table_t h, unsigned long key[], link_t item)	79	void hash_table_insert(hash_table_t h, unsigned long key[], link_t item)
80	{	80	{
81	hash_index_t chain;	81	hash_index_t chain;
82		82
83	assert(item);	83	assert(item);
84	assert(h && h->op && h->op->hash && h->op->compare);	84	assert(h && h->op && h->op->hash && h->op->compare);
85		85
86	chain = h->op->hash(key);	86	chain = h->op->hash(key);
87	assert(chain < h->entries);	87	assert(chain < h->entries);
88		88
89	list_append(item, &h->entry[chain]);	89	list_append(item, &h->entry[chain]);
90	}	90	}
91		91
92	/** Search hash table for an item matching keys.	92	/** Search hash table for an item matching keys.
93	*	93	*
94	* @param h Hash table.	94	* @param h Hash table.
95	* @param key Array of all keys needed to compute hash index.	95	* @param key Array of all keys needed to compute hash index.
96	*	96	*
97	* @return Matching item on success, NULL if there is no such item.	97	* @return Matching item on success, NULL if there is no such item.
98	*/	98	*/
99	link_t hash_table_find(hash_table_t h, unsigned long key[])	99	link_t hash_table_find(hash_table_t h, unsigned long key[])
100	{	100	{
101	link_t *cur;	101	link_t *cur;
102	hash_index_t chain;	102	hash_index_t chain;
103		103
104	assert(h && h->op && h->op->hash && h->op->compare);	104	assert(h && h->op && h->op->hash && h->op->compare);
105		105
106	chain = h->op->hash(key);	106	chain = h->op->hash(key);
107	assert(chain < h->entries);	107	assert(chain < h->entries);
108		108
109	/*	109	/*
110	* The hash table is not redundant.	110	* The hash table is not redundant.
111	* Check if the keys are not in place already.	111	* Check if the keys are not in place already.
112	*/	112	*/
113	for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) {	113	for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) {
114	if (h->op->compare(key, h->max_keys, cur)) {	114	if (h->op->compare(key, h->max_keys, cur)) {
115	/*	115	/*
116	* The entry is there.	116	* The entry is there.
117	*/	117	*/
118	return cur;	118	return cur;
119	}	119	}
120	}	120	}
121		121
122	return NULL;	122	return NULL;
123	}	123	}
124		124
125	/** Remove all matching items from hash table.	125	/** Remove all matching items from hash table.
126	*	126	*
127	* For each removed item, h->remove_callback() is called.	127	* For each removed item, h->remove_callback() is called.
128	*	128	*
129	* @param h Hash table.	129	* @param h Hash table.
130	* @param key Array of keys that will be compared against items of the hash table.	130	* @param key Array of keys that will be compared against items of the hash table.
131	* @param keys Number of keys in the 'key' array.	131	* @param keys Number of keys in the 'key' array.
132	*/	132	*/
133	void hash_table_remove(hash_table_t *h, unsigned long key[], hash_count_t keys)	133	void hash_table_remove(hash_table_t *h, unsigned long key[], hash_count_t keys)
134	{	134	{
135	hash_index_t chain;	135	hash_index_t chain;
136	link_t *cur;	136	link_t *cur;
137		137
138	assert(h && h->op && h->op->hash && h->op->compare && h->op->remove_callback);	138	assert(h && h->op && h->op->hash && h->op->compare && h->op->remove_callback);
139	assert(keys <= h->max_keys);	139	assert(keys <= h->max_keys);
140		140
141	if (keys == h->max_keys) {	141	if (keys == h->max_keys) {
142		142
143	/*	143	/*
144	* All keys are known, hash_table_find() can be used to find the entry.	144	* All keys are known, hash_table_find() can be used to find the entry.
145	*/	145	*/
146		146
147	cur = hash_table_find(h, key);	147	cur = hash_table_find(h, key);
148	if (cur) {	148	if (cur) {
149	list_remove(cur);	149	list_remove(cur);
150	h->op->remove_callback(cur);	150	h->op->remove_callback(cur);
151	}	151	}
152	return;	152	return;
153	}	153	}
154		154
155	/*	155	/*
156	* Fewer keys were passed.	156	* Fewer keys were passed.
157	* Any partially matching entries are to be removed.	157	* Any partially matching entries are to be removed.
158	*/	158	*/
159	for (chain = 0; chain < h->entries; chain++) {	159	for (chain = 0; chain < h->entries; chain++) {
160	for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) {	160	for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) {
161	if (h->op->compare(key, keys, cur)) {	161	if (h->op->compare(key, keys, cur)) {
162	link_t *hlp;	162	link_t *hlp;
163		163
164	hlp = cur;	164	hlp = cur;
165	cur = cur->prev;	165	cur = cur->prev;
166		166
167	list_remove(hlp);	167	list_remove(hlp);
168	h->op->remove_callback(hlp);	168	h->op->remove_callback(hlp);
169		169
170	continue;	170	continue;
171	}	171	}
172	}	172	}
173	}	173	}
174	}	174	}
175		175

Subversion Repositories HelenOS-historic

(root)/uspace/trunk/libadt/generic/hash_table.c – Rev 997 → 1202