WebSVN – HelenOS-historic – Diff – /kernel/trunk/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.
 */
 
/*
 * This is an implementation of generic chained hash table.
 */
 
#include <adt/hash_table.h>
#include <adt/list.h>
#include <typedefs.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)
{
    ASSERT(h);
    ASSERT(op && op->hash && op->compare);
    ASSERT(max_keys > 0);
   
    h->entry = malloc(m * sizeof(link_t *), 0);
    if (!h->entry) {
        panic("cannot allocate memory for hash table\n");
    }
    memsetb((__address) h->entry, m * sizeof(link_t *), 0);
   
    h->entries = m;
    h->max_keys = max_keys;
    h->op = op;
}
 
/** 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, __native 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, __native 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);
   
    /*
     * 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, __native 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 814	Rev 822
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 <adt/hash_table.h>	33	#include <adt/hash_table.h>
34	#include <adt/list.h>	34	#include <adt/list.h>
35	#include <typedefs.h>	35	#include <typedefs.h>
36	#include <arch/types.h>	36	#include <arch/types.h>
37	#include <debug.h>	37	#include <debug.h>
38	#include <mm/slab.h>	38	#include <mm/slab.h>
39	#include <memstr.h>	39	#include <memstr.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	*/	47	*/
48	void hash_table_create(hash_table_t h, count_t m, count_t max_keys, hash_table_operations_t op)	48	void hash_table_create(hash_table_t h, count_t m, count_t max_keys, hash_table_operations_t op)
49	{	49	{
50	ASSERT(h);	50	ASSERT(h);
51	ASSERT(op && op->hash && op->compare);	51	ASSERT(op && op->hash && op->compare);
52	ASSERT(max_keys > 0);	52	ASSERT(max_keys > 0);
53		53
54	h->entry = malloc(m * sizeof(link_t *));	54	h->entry = malloc(m * sizeof(link_t *), 0);
55	if (!h->entry) {	55	if (!h->entry) {
56	panic("cannot allocate memory for hash table\n");	56	panic("cannot allocate memory for hash table\n");
57	}	57	}
58	memsetb((__address) h->entry, m * sizeof(link_t *), 0);	58	memsetb((__address) h->entry, m * sizeof(link_t *), 0);
59		59
60	h->entries = m;	60	h->entries = m;
61	h->max_keys = max_keys;	61	h->max_keys = max_keys;
62	h->op = op;	62	h->op = op;
63	}	63	}
64		64
65	/** Insert item into hash table.	65	/** Insert item into hash table.
66	*	66	*
67	* @param h Hash table.	67	* @param h Hash table.
68	* @param hey Array of all keys necessary to compute hash index.	68	* @param hey Array of all keys necessary to compute hash index.
69	* @param item Item to be inserted into the hash table.	69	* @param item Item to be inserted into the hash table.
70	*/	70	*/
71	void hash_table_insert(hash_table_t h, __native key[], link_t item)	71	void hash_table_insert(hash_table_t h, __native key[], link_t item)
72	{	72	{
73	index_t chain;	73	index_t chain;
74		74
75	ASSERT(item);	75	ASSERT(item);
76	ASSERT(h && h->op && h->op->hash && h->op->compare);	76	ASSERT(h && h->op && h->op->hash && h->op->compare);
77		77
78	chain = h->op->hash(key);	78	chain = h->op->hash(key);
79	ASSERT(chain < h->entries);	79	ASSERT(chain < h->entries);
80		80
81	list_append(item, &h->entry[chain]);	81	list_append(item, &h->entry[chain]);
82	}	82	}
83		83
84	/** Search hash table for an item matching keys.	84	/** Search hash table for an item matching keys.
85	*	85	*
86	* @param h Hash table.	86	* @param h Hash table.
87	* @param key Array of all keys needed to compute hash index.	87	* @param key Array of all keys needed to compute hash index.
88	*	88	*
89	* @return Matching item on success, NULL if there is no such item.	89	* @return Matching item on success, NULL if there is no such item.
90	*/	90	*/
91	link_t hash_table_find(hash_table_t h, __native key[])	91	link_t hash_table_find(hash_table_t h, __native key[])
92	{	92	{
93	link_t *cur;	93	link_t *cur;
94	index_t chain;	94	index_t chain;
95		95
96	ASSERT(h && h->op && h->op->hash && h->op->compare);	96	ASSERT(h && h->op && h->op->hash && h->op->compare);
97		97
98	chain = h->op->hash(key);	98	chain = h->op->hash(key);
99	ASSERT(chain < h->entries);	99	ASSERT(chain < h->entries);
100		100
101	/*	101	/*
102	* The hash table is not redundant.	102	* The hash table is not redundant.
103	* Check if the keys are not in place already.	103	* Check if the keys are not in place already.
104	*/	104	*/
105	for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) {	105	for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) {
106	if (h->op->compare(key, h->max_keys, cur)) {	106	if (h->op->compare(key, h->max_keys, cur)) {
107	/*	107	/*
108	* The entry is there.	108	* The entry is there.
109	*/	109	*/
110	return cur;	110	return cur;
111	}	111	}
112	}	112	}
113		113
114	return NULL;	114	return NULL;
115	}	115	}
116		116
117	/** Remove all matching items from hash table.	117	/** Remove all matching items from hash table.
118	*	118	*
119	* For each removed item, h->remove_callback() is called.	119	* For each removed item, h->remove_callback() is called.
120	*	120	*
121	* @param h Hash table.	121	* @param h Hash table.
122	* @param key Array of keys that will be compared against items of the hash table.	122	* @param key Array of keys that will be compared against items of the hash table.
123	* @param keys Number of keys in the 'key' array.	123	* @param keys Number of keys in the 'key' array.
124	*/	124	*/
125	void hash_table_remove(hash_table_t *h, __native key[], count_t keys)	125	void hash_table_remove(hash_table_t *h, __native key[], count_t keys)
126	{	126	{
127	index_t chain;	127	index_t chain;
128	link_t *cur;	128	link_t *cur;
129		129
130	ASSERT(h && h->op && h->op->hash && h->op->compare && h->op->remove_callback);	130	ASSERT(h && h->op && h->op->hash && h->op->compare && h->op->remove_callback);
131	ASSERT(keys <= h->max_keys);	131	ASSERT(keys <= h->max_keys);
132		132
133	if (keys == h->max_keys) {	133	if (keys == h->max_keys) {
134		134
135	/*	135	/*
136	* All keys are known, hash_table_find() can be used to find the entry.	136	* All keys are known, hash_table_find() can be used to find the entry.
137	*/	137	*/
138		138
139	cur = hash_table_find(h, key);	139	cur = hash_table_find(h, key);
140	if (cur) {	140	if (cur) {
141	list_remove(cur);	141	list_remove(cur);
142	h->op->remove_callback(cur);	142	h->op->remove_callback(cur);
143	}	143	}
144	return;	144	return;
145	}	145	}
146		146
147	/*	147	/*
148	* Fewer keys were passed.	148	* Fewer keys were passed.
149	* Any partially matching entries are to be removed.	149	* Any partially matching entries are to be removed.
150	*/	150	*/
151	for (chain = 0; chain < h->entries; chain++) {	151	for (chain = 0; chain < h->entries; chain++) {
152	for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) {	152	for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) {
153	if (h->op->compare(key, keys, cur)) {	153	if (h->op->compare(key, keys, cur)) {
154	link_t *hlp;	154	link_t *hlp;
155		155
156	hlp = cur;	156	hlp = cur;
157	cur = cur->prev;	157	cur = cur->prev;
158		158
159	list_remove(hlp);	159	list_remove(hlp);
160	h->op->remove_callback(hlp);	160	h->op->remove_callback(hlp);
161		161
162	continue;	162	continue;
163	}	163	}
164	}	164	}
165	}	165	}
166	}	166	}
167		167

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/generic/src/adt/hash_table.c – Rev 814 → 822