1 files changed, 125 insertions, 0 deletions
diff --git a/libapol/src/queue.c b/libapol/src/queue.c
new file mode 100644
index 0000000..1a3de23
--- /dev/null
+++ b/libapol/src/queue.c
@@ -0,0 +1,125 @@
+/**
+ * @file
+ *
+ * This file is a copy of queue.h from NSA's CVS repository.  It has
+ * been modified to follow the setools naming conventions.
+ *
+ * Author : Stephen Smalley (NSA), <sds@epoch.ncsc.mil>
+ *
+ * Implementation of the double-ended queue type.
+ */
+
+#include <stdlib.h>
+#include "queue.h"
+
+apol_queue_t *apol_queue_create(void)
+{
+	apol_queue_t *q;
+
+	q = (apol_queue_t *) malloc(sizeof(apol_queue_t));
+	if (q == NULL)
+		return NULL;
+
+	q->head = q->tail = NULL;
+
+	return q;
+}
+
+int apol_queue_insert(apol_queue_t * q, void *element)
+{
+	apol_queue_node_t *newnode;
+
+	if (!q)
+		return -1;
+
+	newnode = (apol_queue_node_t *) malloc(sizeof(struct apol_queue_node));
+	if (newnode == NULL)
+		return -1;
+
+	newnode->element = element;
+	newnode->next = NULL;
+
+	if (q->head == NULL) {
+		q->head = q->tail = newnode;
+	} else {
+		q->tail->next = newnode;
+		q->tail = newnode;
+	}
+
+	return 0;
+}
+
+int apol_queue_push(apol_queue_t * q, void *element)
+{
+	apol_queue_node_t *newnode;
+
+	if (!q)
+		return -1;
+
+	newnode = (apol_queue_node_t *) malloc(sizeof(apol_queue_node_t));
+	if (newnode == NULL)
+		return -1;
+
+	newnode->element = element;
+	newnode->next = NULL;
+
+	if (q->head == NULL) {
+		q->head = q->tail = newnode;
+	} else {
+		newnode->next = q->head;
+		q->head = newnode;
+	}
+
+	return 0;
+}
+
+void *apol_queue_remove(apol_queue_t * q)
+{
+	apol_queue_node_t *node;
+	void *element;
+
+	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;
+
+	element = node->element;
+	free(node);
+
+	return element;
+}
+
+void *apol_queue_head(apol_queue_t * q)
+{
+	if (!q)
+		return NULL;
+
+	if (q->head == NULL)
+		return NULL;
+
+	return q->head->element;
+}
+
+void apol_queue_destroy(apol_queue_t ** q)
+{
+	apol_queue_node_t *p, *temp;
+
+	if (!q || *q == NULL)
+		return;
+
+	p = (*q)->head;
+	while (p != NULL) {
+		temp = p;
+		p = p->next;
+		free(temp);
+	}
+
+	free(*q);
+	*q = NULL;
+}