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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <stdlib.h>
#include <assert.h>
#include <pthread.h>
#include "sip_hash.h"
/*
* This file implements functions that add, search or remove an object
* from the hash table. The object is opaque to the hash functions. To add
* an object to the hash table, the caller provides the hash table,
* the object and the index into the hash table. To search an object,
* the caller provides the hash table, the digest (opaque), the index into
* the hash table and the function that does the actual match. Similarly,
* for removing an object, the caller provides the hash table, the digest
* (opaque), the index into the hash table and the function that does
* the acutal deletion of the object - if the deletion is successful,
* the object is taken off of the hash table.
*/
/*
* Given an object and the hash index, add it to the given hash table
*/
int
sip_hash_add(sip_hash_t *sip_hash, void *obj, int hindex)
{
sip_hash_obj_t *new_obj;
sip_hash_t *hash_entry;
assert(obj != NULL);
new_obj = (sip_hash_obj_t *)malloc(sizeof (*new_obj));
if (new_obj == NULL)
return (-1);
new_obj->sip_obj = obj;
new_obj->next_obj = NULL;
new_obj->prev_obj = NULL;
hash_entry = &sip_hash[hindex];
(void) pthread_mutex_lock(&hash_entry->sip_hash_mutex);
if (hash_entry->hash_count == 0) {
assert(hash_entry->hash_head == NULL);
assert(hash_entry->hash_tail == NULL);
hash_entry->hash_head = new_obj;
} else {
hash_entry->hash_tail->next_obj = new_obj;
new_obj->prev_obj = hash_entry->hash_tail;
}
hash_entry->hash_tail = new_obj;
hash_entry->hash_count++;
(void) pthread_mutex_unlock(&hash_entry->sip_hash_mutex);
return (0);
}
/*
* Given the hash table, the digest to be searched for, index into the hash
* table and the function to do the actual matching, return the object,
* if found.
*/
void *
sip_hash_find(sip_hash_t *sip_hash, void *digest, int hindex,
boolean_t (*match_func)(void *, void *))
{
int count;
sip_hash_obj_t *tmp;
sip_hash_t *hash_entry;
hash_entry = &sip_hash[hindex];
(void) pthread_mutex_lock(&hash_entry->sip_hash_mutex);
tmp = hash_entry->hash_head;
for (count = 0; count < hash_entry->hash_count; count++) {
if (match_func(tmp->sip_obj, digest)) {
(void) pthread_mutex_unlock(
&hash_entry->sip_hash_mutex);
return (tmp->sip_obj);
}
tmp = tmp->next_obj;
}
(void) pthread_mutex_unlock(&hash_entry->sip_hash_mutex);
return (NULL);
}
/*
* Walk the hash table and invoke func on each object. 'arg' is passed
* to 'func'
*/
void
sip_walk_hash(sip_hash_t *sip_hash, void (*func)(void *, void *), void *arg)
{
sip_hash_t *hash_entry;
int count;
int hcount;
sip_hash_obj_t *tmp;
for (count = 0; count < SIP_HASH_SZ; count++) {
hash_entry = &sip_hash[count];
(void) pthread_mutex_lock(&hash_entry->sip_hash_mutex);
tmp = hash_entry->hash_head;
for (hcount = 0; hcount < hash_entry->hash_count; hcount++) {
assert(tmp->sip_obj != NULL);
func(tmp->sip_obj, arg);
tmp = tmp->next_obj;
}
(void) pthread_mutex_unlock(&hash_entry->sip_hash_mutex);
}
}
/*
* Given the hash table, the digest to be searched for, the index into the
* hash table and the delete function provided to do the actual deletion,
* remove the object from the hash table (i.e. only if the object is deleted).
*/
void
sip_hash_delete(sip_hash_t *sip_hash, void *digest, int hindex,
boolean_t (*del_func)(void *, void *, int *))
{
sip_hash_t *hash_entry;
int count;
sip_hash_obj_t *tmp;
int found;
hash_entry = &sip_hash[hindex];
(void) pthread_mutex_lock(&hash_entry->sip_hash_mutex);
tmp = hash_entry->hash_head;
for (count = 0; count < hash_entry->hash_count; count++) {
if (del_func(tmp->sip_obj, digest, &found)) {
if (tmp == hash_entry->hash_head) {
if (tmp->next_obj != NULL) {
hash_entry->hash_head = tmp->next_obj;
tmp->next_obj->prev_obj = NULL;
} else {
assert(hash_entry->hash_tail ==
hash_entry->hash_head);
hash_entry->hash_head = NULL;
hash_entry->hash_tail = NULL;
}
} else {
sip_hash_obj_t *next = tmp->next_obj;
if (next != NULL) {
tmp->prev_obj->next_obj = next;
next->prev_obj = tmp->prev_obj;
} else {
assert(hash_entry->hash_tail == tmp);
tmp->prev_obj->next_obj = NULL;
hash_entry->hash_tail =
tmp->prev_obj;
}
}
tmp->prev_obj = NULL;
tmp->next_obj = NULL;
free(tmp);
hash_entry->hash_count--;
(void) pthread_mutex_unlock(
&hash_entry->sip_hash_mutex);
return;
/*
* If we found the object, we are done
*/
} else if (found == 1) {
(void) pthread_mutex_unlock(
&hash_entry->sip_hash_mutex);
return;
}
tmp = tmp->next_obj;
}
(void) pthread_mutex_unlock(&hash_entry->sip_hash_mutex);
}
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