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/*
* Copyright (c) 1999 The University of Utah and the Flux Group.
* All rights reserved.
*
* Contributed by the Computer Security Research division,
* INFOSEC Research and Technology Office, NSA.
*
* This file is part of the Flux OSKit. The OSKit is free software, also known
* as "open source;" you can redistribute it and/or modify it under the terms
* of the GNU General Public License (GPL), version 2, as published by the Free
* Software Foundation (FSF). To explore alternate licensing terms, contact
* the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
*
* The OSKit is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GPL for more details. You should have
* received a copy of the GPL along with the OSKit; see the file COPYING. If
* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
*/
/* FLASK */
/*
* queue.c
*
* Implementation of a generic queue type.
*/
#include "queue.h"
queue_t
queue_create(void)
{
queue_t q;
q = (queue_t) MALLOC(sizeof(struct queue_info_t));
if (q == NULL)
return NULL;
q->head = q->tail = NULL;
return q;
}
int
queue_insert(queue_t q, queue_element_t e)
{
queue_node_ptr_t newnode;
if (!q)
return -1;
newnode = (queue_node_ptr_t) MALLOC(sizeof(struct queue_node_t));
if (newnode == NULL)
return -1;
newnode->element = e;
newnode->next = NULL;
if (q->head == NULL) {
q->head = q->tail = newnode;
} else {
q->tail->next = newnode;
q->tail = newnode;
}
return 0;
}
int
queue_push(queue_t q, queue_element_t e)
{
queue_node_ptr_t newnode;
if (!q)
return -1;
newnode = (queue_node_ptr_t) MALLOC(sizeof(struct queue_node_t));
if (newnode == NULL)
return -1;
newnode->element = e;
newnode->next = NULL;
if (q->head == NULL) {
q->head = q->tail = newnode;
} else {
newnode->next = q->head;
q->head = newnode;
}
return 0;
}
queue_element_t
queue_remove(queue_t q)
{
queue_node_ptr_t node;
queue_element_t e;
if (!q)
return NULL;
if (q->head == NULL)
return NULL;
node = q->head;
q->head = q->head->next;
if (q->head == NULL)
q->tail = NULL;
e = node->element;
FREE(node, sizeof(struct queue_node_t));
return e;
}
queue_element_t
queue_head(queue_t q)
{
if (!q)
return NULL;
if (q->head == NULL)
return NULL;
return q->head->element;
}
void
queue_destroy(queue_t q)
{
queue_node_ptr_t p, temp;
if (!q)
return;
p = q->head;
while (p != NULL) {
temp = p;
p = p->next;
FREE(temp, sizeof(struct queue_node_t));
}
FREE(q, sizeof(struct queue_info_t));
}
int queue_map(queue_t q, int (*f) (queue_element_t, void *), void *vp) {
queue_node_ptr_t p;
int ret;
if (!q)
return 0;
p = q->head;
while (p != NULL) {
ret = f(p->element, vp);
if (ret)
return ret;
p = p->next;
}
return 0;
}
void
queue_map_remove_on_error(queue_t q,
int (*f) (queue_element_t, void *),
void (*g) (queue_element_t, void *),
void *vp)
{
queue_node_ptr_t p, last, temp;
int ret;
if (!q)
return;
last = NULL;
p = q->head;
while (p != NULL) {
ret = f(p->element, vp);
if (ret) {
if (last) {
last->next = p->next;
if (last->next == NULL)
q->tail = last;
} else {
q->head = p->next;
if (q->head == NULL)
q->tail = NULL;
}
temp = p;
p = p->next;
g(temp->element, vp);
FREE(temp, sizeof(struct queue_node_t));
} else {
last = p;
p = p->next;
}
}
return;
}
/* FLASK */
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