WebSVN – HelenOS – Diff – /trunk/kernel/generic/src/adt/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.
 */
 
/** @addtogroup genericadt
 * @{
 */
 
/**
 * @file
 * @brief   Implementation of generic chained hash table.
 *
 * This file contains implementation of generic chained hash table.
 */
 
#include <adt/hash_table.h>
#include <adt/list.h>
#include <arch/types.h>
#include <debug.h>
#include <mm/slab.h>
#include <memstr.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.
 */
void hash_table_create(hash_table_t *h, count_t m, count_t max_keys, hash_table_operations_t *op)
{
    index_t i;
 
    ASSERT(h);
    ASSERT(op && op->hash && op->compare);
    ASSERT(max_keys > 0);
   
    h->entry = (link_t *) malloc(m * sizeof(link_t), 0);
    if (!h->entry) {
        panic("Cannot allocate memory for hash table.");
    }
    memsetb(h->entry, m * sizeof(link_t), 0);
   
    for (i = 0; i < m; i++)
        list_initialize(&h->entry[i]);
   
    h->entries = m;
    h->max_keys = max_keys;
    h->op = op;
}
 
/** Insert item into hash table.
 *
 * @param h Hash table.
 * @param key 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, unative_t key[], link_t *item)
{
    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, unative_t key[])
{
    link_t *cur;
    index_t chain;
 
    ASSERT(h && h->op && h->op->hash && h->op->compare);
 
    chain = h->op->hash(key);
    ASSERT(chain < h->entries);
   
    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, unative_t key[], count_t keys)
{
    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 3104	Rev 3790
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	/** @addtogroup genericadt	29	/** @addtogroup genericadt
30	* @{	30	* @{
31	*/	31	*/
32		32
33	/**	33	/**
34	* @file	34	* @file
35	* @brief Implementation of generic chained hash table.	35	* @brief Implementation of generic chained hash table.
36	*	36	*
37	* This file contains implementation of generic chained hash table.	37	* This file contains implementation of generic chained hash table.
38	*/	38	*/
39		39
40	#include <adt/hash_table.h>	40	#include <adt/hash_table.h>
41	#include <adt/list.h>	41	#include <adt/list.h>
42	#include <arch/types.h>	42	#include <arch/types.h>
43	#include <debug.h>	43	#include <debug.h>
44	#include <mm/slab.h>	44	#include <mm/slab.h>
45	#include <memstr.h>	45	#include <memstr.h>
46		46
47	/** Create chained hash table.	47	/** Create chained hash table.
48	*	48	*
49	* @param h Hash table structure. Will be initialized by this call.	49	* @param h Hash table structure. Will be initialized by this call.
50	* @param m Number of slots in the hash table.	50	* @param m Number of slots in the hash table.
51	* @param max_keys Maximal number of keys needed to identify an item.	51	* @param max_keys Maximal number of keys needed to identify an item.
52	* @param op Hash table operations structure.	52	* @param op Hash table operations structure.
53	*/	53	*/
54	void hash_table_create(hash_table_t h, count_t m, count_t max_keys, hash_table_operations_t op)	54	void hash_table_create(hash_table_t h, count_t m, count_t max_keys, hash_table_operations_t op)
55	{	55	{
56	index_t i;	56	index_t i;
57		57
58	ASSERT(h);	58	ASSERT(h);
59	ASSERT(op && op->hash && op->compare);	59	ASSERT(op && op->hash && op->compare);
60	ASSERT(max_keys > 0);	60	ASSERT(max_keys > 0);
61		61
62	h->entry = (link_t ) malloc(m sizeof(link_t), 0);	62	h->entry = (link_t ) malloc(m sizeof(link_t), 0);
63	if (!h->entry) {	63	if (!h->entry) {
64	panic("cannot allocate memory for hash table\n");	64	panic("Cannot allocate memory for hash table.");
65	}	65	}
66	memsetb(h->entry, m * sizeof(link_t), 0);	66	memsetb(h->entry, m * sizeof(link_t), 0);
67		67
68	for (i = 0; i < m; i++)	68	for (i = 0; i < m; i++)
69	list_initialize(&h->entry[i]);	69	list_initialize(&h->entry[i]);
70		70
71	h->entries = m;	71	h->entries = m;
72	h->max_keys = max_keys;	72	h->max_keys = max_keys;
73	h->op = op;	73	h->op = op;
74	}	74	}
75		75
76	/** Insert item into hash table.	76	/** Insert item into hash table.
77	*	77	*
78	* @param h Hash table.	78	* @param h Hash table.
79	* @param key Array of all keys necessary to compute hash index.	79	* @param key Array of all keys necessary to compute hash index.
80	* @param item Item to be inserted into the hash table.	80	* @param item Item to be inserted into the hash table.
81	*/	81	*/
82	void hash_table_insert(hash_table_t h, unative_t key[], link_t item)	82	void hash_table_insert(hash_table_t h, unative_t key[], link_t item)
83	{	83	{
84	index_t chain;	84	index_t chain;
85		85
86	ASSERT(item);	86	ASSERT(item);
87	ASSERT(h && h->op && h->op->hash && h->op->compare);	87	ASSERT(h && h->op && h->op->hash && h->op->compare);
88		88
89	chain = h->op->hash(key);	89	chain = h->op->hash(key);
90	ASSERT(chain < h->entries);	90	ASSERT(chain < h->entries);
91		91
92	list_append(item, &h->entry[chain]);	92	list_append(item, &h->entry[chain]);
93	}	93	}
94		94
95	/** Search hash table for an item matching keys.	95	/** Search hash table for an item matching keys.
96	*	96	*
97	* @param h Hash table.	97	* @param h Hash table.
98	* @param key Array of all keys needed to compute hash index.	98	* @param key Array of all keys needed to compute hash index.
99	*	99	*
100	* @return Matching item on success, NULL if there is no such item.	100	* @return Matching item on success, NULL if there is no such item.
101	*/	101	*/
102	link_t hash_table_find(hash_table_t h, unative_t key[])	102	link_t hash_table_find(hash_table_t h, unative_t key[])
103	{	103	{
104	link_t *cur;	104	link_t *cur;
105	index_t chain;	105	index_t chain;
106		106
107	ASSERT(h && h->op && h->op->hash && h->op->compare);	107	ASSERT(h && h->op && h->op->hash && h->op->compare);
108		108
109	chain = h->op->hash(key);	109	chain = h->op->hash(key);
110	ASSERT(chain < h->entries);	110	ASSERT(chain < h->entries);
111		111
112	for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) {	112	for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) {
113	if (h->op->compare(key, h->max_keys, cur)) {	113	if (h->op->compare(key, h->max_keys, cur)) {
114	/*	114	/*
115	* The entry is there.	115	* The entry is there.
116	*/	116	*/
117	return cur;	117	return cur;
118	}	118	}
119	}	119	}
120		120
121	return NULL;	121	return NULL;
122	}	122	}
123		123
124	/** Remove all matching items from hash table.	124	/** Remove all matching items from hash table.
125	*	125	*
126	* For each removed item, h->remove_callback() is called.	126	* For each removed item, h->remove_callback() is called.
127	*	127	*
128	* @param h Hash table.	128	* @param h Hash table.
129	* @param key Array of keys that will be compared against items of the hash table.	129	* @param key Array of keys that will be compared against items of the hash table.
130	* @param keys Number of keys in the key array.	130	* @param keys Number of keys in the key array.
131	*/	131	*/
132	void hash_table_remove(hash_table_t *h, unative_t key[], count_t keys)	132	void hash_table_remove(hash_table_t *h, unative_t key[], count_t keys)
133	{	133	{
134	index_t chain;	134	index_t chain;
135	link_t *cur;	135	link_t *cur;
136		136
137	ASSERT(h && h->op && h->op->hash && h->op->compare && h->op->remove_callback);	137	ASSERT(h && h->op && h->op->hash && h->op->compare && h->op->remove_callback);
138	ASSERT(keys <= h->max_keys);	138	ASSERT(keys <= h->max_keys);
139		139
140	if (keys == h->max_keys) {	140	if (keys == h->max_keys) {
141		141
142	/*	142	/*
143	* All keys are known, hash_table_find() can be used to find the entry.	143	* All keys are known, hash_table_find() can be used to find the entry.
144	*/	144	*/
145		145
146	cur = hash_table_find(h, key);	146	cur = hash_table_find(h, key);
147	if (cur) {	147	if (cur) {
148	list_remove(cur);	148	list_remove(cur);
149	h->op->remove_callback(cur);	149	h->op->remove_callback(cur);
150	}	150	}
151	return;	151	return;
152	}	152	}
153		153
154	/*	154	/*
155	* Fewer keys were passed.	155	* Fewer keys were passed.
156	* Any partially matching entries are to be removed.	156	* Any partially matching entries are to be removed.
157	*/	157	*/
158	for (chain = 0; chain < h->entries; chain++) {	158	for (chain = 0; chain < h->entries; chain++) {
159	for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) {	159	for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) {
160	if (h->op->compare(key, keys, cur)) {	160	if (h->op->compare(key, keys, cur)) {
161	link_t *hlp;	161	link_t *hlp;
162		162
163	hlp = cur;	163	hlp = cur;
164	cur = cur->prev;	164	cur = cur->prev;
165		165
166	list_remove(hlp);	166	list_remove(hlp);
167	h->op->remove_callback(hlp);	167	h->op->remove_callback(hlp);
168		168
169	continue;	169	continue;
170	}	170	}
171	}	171	}
172	}	172	}
173	}	173	}
174		174
175	/** @}	175	/** @}
176	*/	176	*/
177		177

Subversion Repositories HelenOS

(root)/trunk/kernel/generic/src/adt/hash_table.c – Rev 3104 → 3790