1 files changed, 103 insertions, 0 deletions
diff --git a/libqueue/queue/dl.c b/libqueue/queue/dl.c
new file mode 100644
index 0000000..65e024d
--- /dev/null
+++ b/libqueue/queue/dl.c
@@ -0,0 +1,103 @@
+/* vim: set ts=4 sw=4 ai:
+ * dl.c -- doubly linked list implementation derived from NetBSD's queue.h
+ */
+
+#include <stdlib.h>
+#include "dl.h"
+
+struct dlh *dl_new(void)
+{
+	struct dlh *hd;
+
+	hd = malloc(sizeof(*hd));
+	if (hd != NULL)
+		dl_init(hd);
+
+	return hd;
+}
+
+struct dle *dl_elem_new(void *data)
+{
+	struct dle *e;
+
+	e = malloc(sizeof(*e));
+	if (e != NULL)
+		e->data = data;
+
+	return e;
+}
+
+void dl_insert_after(struct dle *e, struct dle *n)
+{
+	if ((n->next = e->next) != NULL)
+		 e->next->pprev = &n->next;
+	e->next = n;
+	n->pprev = &e->next;
+}
+
+void dl_insert_before(struct dle *e, struct dle *n)
+{
+	n->pprev = e->pprev;
+	n->next = e;
+	*e->pprev = n;
+	e->pprev = &n->next;
+}
+
+void dl_insert_head(struct dlh *hd, struct dle *e)
+{
+ 	if ((e->next = hd->first) != NULL)
+		hd->first->pprev = &e->next;
+	hd->first = e;
+	e->pprev = &hd->first;
+}
+
+void dl_remove(struct dlh *hd, struct dle *e)
+{
+	if (e->next != NULL)
+		e->next->pprev = e->pprev;
+	*e->pprev = e->next;
+}
+
+void dl_replace(struct dle *e1, struct dle *e2)
+{
+ 	if ((e2->next = e1->next) != NULL)
+		e2->next->pprev = &e2->next;
+	e2->pprev = e1->pprev;
+
+	*e2->pprev = e2;
+}
+
+void dlist_move(struct dlh *hd1, struct dlh *hd2)
+{
+ 	hd2->first = NULL;
+	if (!(hd1->first == NULL))
+	{
+		hd2->first = hd1->first;
+		hd2->first->pprev = &hd2->first;
+		hd1->first = NULL;
+	}
+}
+
+void dl_cleanup(struct dlh *hd, void (*func)(void *))
+{
+	struct dle *e, *t;
+
+	dl_foreach_safe(e, hd, t) {
+		dl_remove(hd, e);
+		if (func)
+			func(e->data);
+		free(e);
+	}
+}
+
+struct dle *dl_find_from_data(struct dlh *hd, const void *data, int (*cmp)(const void *, const void *))
+{
+	struct dle *e;
+
+	if (hd && !dl_empty(hd))
+		dl_foreach(e, hd)
+			if (e->data && cmp(e->data, data) == 0)
+				return e;
+
+	return NULL;
+}