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 996	Rev 997
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>
-		39	#include <string.h>
38		40
39	/** Create chained hash table.	41	/** Create chained hash table.
40	*	42	*
41	* @param h Hash table structure. Will be initialized by this call.	43	* @param h Hash table structure. Will be initialized by this call.
42	* @param m Number of slots in the hash table.	44	* @param m Number of slots in the hash table.
43	* @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.
44	* @param op Hash table operations structure.	46	* @param op Hash table operations structure.
-		47	* @return true on success
45	*/	48	*/
46	void 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)
47	{	50	{
48	int i;	51	hash_count_t i;
49		52
50	ASSERT(h);	53	assert(h);
51	ASSERT(op && op->hash && op->compare);	54	assert(op && op->hash && op->compare);
52	ASSERT(max_keys > 0);	55	assert(max_keys > 0);
53		56
54	h->entry = malloc(m * sizeof(link_t *), 0);	57	h->entry = malloc(m * sizeof(link_t *));
55	if (!h->entry) {	58	if (!h->entry) {
56	panic("cannot allocate memory for hash table\n");	59	printf("cannot allocate memory for hash table\n");
-		60	return false;
57	}	61	}
58	memsetb((__address) h->entry, m * sizeof(link_t *), 0);	62	memset((void ) h->entry, 0, m sizeof(link_t *));
59		63
60	for (i = 0; i < m; i++)	64	for (i = 0; i < m; i++)
61	list_initialize(&h->entry[i]);	65	list_initialize(&h->entry[i]);
62		66
63	h->entries = m;	67	h->entries = m;
64	h->max_keys = max_keys;	68	h->max_keys = max_keys;
65	h->op = op;	69	h->op = op;
-		70	return true;
66	}	71	}
67		72
68	/** Insert item into hash table.	73	/** Insert item into hash table.
69	*	74	*
70	* @param h Hash table.	75	* @param h Hash table.
71	* @param hey Array of all keys necessary to compute hash index.	76	* @param hey Array of all keys necessary to compute hash index.
72	* @param item Item to be inserted into the hash table.	77	* @param item Item to be inserted into the hash table.
73	*/	78	*/
74	void hash_table_insert(hash_table_t h, __native key[], link_t item)	79	void hash_table_insert(hash_table_t h, unsigned long key[], link_t item)
75	{	80	{
76	hash_index_t chain;	81	hash_index_t chain;
77		82
78	ASSERT(item);	83	assert(item);
79	ASSERT(h && h->op && h->op->hash && h->op->compare);	84	assert(h && h->op && h->op->hash && h->op->compare);
80		85
81	chain = h->op->hash(key);	86	chain = h->op->hash(key);
82	ASSERT(chain < h->entries);	87	assert(chain < h->entries);
83		88
84	list_append(item, &h->entry[chain]);	89	list_append(item, &h->entry[chain]);
85	}	90	}
86		91
87	/** Search hash table for an item matching keys.	92	/** Search hash table for an item matching keys.
88	*	93	*
89	* @param h Hash table.	94	* @param h Hash table.
90	* @param key Array of all keys needed to compute hash index.	95	* @param key Array of all keys needed to compute hash index.
91	*	96	*
92	* @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.
93	*/	98	*/
94	link_t hash_table_find(hash_table_t h, __native key[])	99	link_t hash_table_find(hash_table_t h, unsigned long key[])
95	{	100	{
96	link_t *cur;	101	link_t *cur;
97	hash_index_t chain;	102	hash_index_t chain;
98		103
99	ASSERT(h && h->op && h->op->hash && h->op->compare);	104	assert(h && h->op && h->op->hash && h->op->compare);
100		105
101	chain = h->op->hash(key);	106	chain = h->op->hash(key);
102	ASSERT(chain < h->entries);	107	assert(chain < h->entries);
103		108
104	/*	109	/*
105	* The hash table is not redundant.	110	* The hash table is not redundant.
106	* Check if the keys are not in place already.	111	* Check if the keys are not in place already.
107	*/	112	*/
108	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) {
109	if (h->op->compare(key, h->max_keys, cur)) {	114	if (h->op->compare(key, h->max_keys, cur)) {
110	/*	115	/*
111	* The entry is there.	116	* The entry is there.
112	*/	117	*/
113	return cur;	118	return cur;
114	}	119	}
115	}	120	}
116		121
117	return NULL;	122	return NULL;
118	}	123	}
119		124
120	/** Remove all matching items from hash table.	125	/** Remove all matching items from hash table.
121	*	126	*
122	* For each removed item, h->remove_callback() is called.	127	* For each removed item, h->remove_callback() is called.
123	*	128	*
124	* @param h Hash table.	129	* @param h Hash table.
125	* @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.
126	* @param keys Number of keys in the 'key' array.	131	* @param keys Number of keys in the 'key' array.
127	*/	132	*/
128	void hash_table_remove(hash_table_t *h, __native key[], hash_count_t keys)	133	void hash_table_remove(hash_table_t *h, unsigned long key[], hash_count_t keys)
129	{	134	{
130	hash_index_t chain;	135	hash_index_t chain;
131	link_t *cur;	136	link_t *cur;
132		137
133	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);
134	ASSERT(keys <= h->max_keys);	139	assert(keys <= h->max_keys);
135		140
136	if (keys == h->max_keys) {	141	if (keys == h->max_keys) {
137		142
138	/*	143	/*
139	* 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.
140	*/	145	*/
141		146
142	cur = hash_table_find(h, key);	147	cur = hash_table_find(h, key);
143	if (cur) {	148	if (cur) {
144	list_remove(cur);	149	list_remove(cur);
145	h->op->remove_callback(cur);	150	h->op->remove_callback(cur);
146	}	151	}
147	return;	152	return;
148	}	153	}
149		154
150	/*	155	/*
151	* Fewer keys were passed.	156	* Fewer keys were passed.
152	* Any partially matching entries are to be removed.	157	* Any partially matching entries are to be removed.
153	*/	158	*/
154	for (chain = 0; chain < h->entries; chain++) {	159	for (chain = 0; chain < h->entries; chain++) {
155	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) {
156	if (h->op->compare(key, keys, cur)) {	161	if (h->op->compare(key, keys, cur)) {
157	link_t *hlp;	162	link_t *hlp;
158		163
159	hlp = cur;	164	hlp = cur;
160	cur = cur->prev;	165	cur = cur->prev;
161		166
162	list_remove(hlp);	167	list_remove(hlp);
163	h->op->remove_callback(hlp);	168	h->op->remove_callback(hlp);
164		169
165	continue;	170	continue;
166	}	171	}
167	}	172	}
168	}	173	}
169	}	174	}
170		175

Subversion Repositories HelenOS-historic

(root)/uspace/trunk/libadt/generic/hash_table.c – Rev 996 → 997