1 files changed, 120 insertions, 0 deletions
diff --git a/libqueue/queue/tq.c b/libqueue/queue/tq.c
new file mode 100644
index 0000000..d55b63a
--- /dev/null
+++ b/libqueue/queue/tq.c
@@ -0,0 +1,120 @@
+/* vim: set ts=4 sw=4 ai:
+ * tq.c -- tail queue implementation derived from NetBSD's queue.h
+ */
+
+#include <stdlib.h>
+#include "tq.h"
+
+struct tqh *tq_new(void)
+{
+	struct tqh *hd;
+
+	hd = malloc(sizeof(*hd));
+	if (hd != NULL)
+		tq_init(hd);
+
+	return hd;
+}
+
+struct tqe *tq_elem_new(void *data)
+{
+	struct tqe *e;
+
+	e = malloc(sizeof(*e));
+	if (e != NULL)
+		e->data = data;
+
+	return e;
+}
+
+void tq_insert_head(struct tqh *hd, struct tqe *e)
+{
+	if ((e->next = hd->first) != NULL)
+		hd->first->pprev = &e->next;
+	else
+		hd->last = &e->next;
+	hd->first = e;
+	e->pprev = &hd->first;
+}
+
+void tq_insert_tail(struct tqh *hd, struct tqe *e)
+{
+	e->next = NULL;
+	e->pprev = hd->last;
+	*hd->last = e;
+	hd->last = &e->next;
+}
+
+void tq_insert_after(struct tqh *hd, struct tqe *e, struct tqe *n)
+{
+	if ((n->next = e->next) != NULL)
+		n->next->pprev = &n->next;
+	else
+		hd->last = &n->next;
+	e->next = n;
+	n->pprev = &e->next;
+}
+
+void tq_insert_before(struct tqh *hd, struct tqe *e, struct tqe *n)
+{
+	n->pprev = e->pprev;
+	n->next = e;
+	*e->pprev = n;
+	e->pprev = &n->next;
+	if (hd->first == e)
+		hd->first = n;
+}
+
+void tq_remove(struct tqh *hd, struct tqe *e)
+{
+	if ((e->next) != NULL)
+		e->next->pprev = e->pprev;
+	else
+		hd->last = e->pprev;
+	*e->pprev = e->next;
+}
+
+void tq_replace(struct tqh *hd, struct tqe *e, struct tqe *n)
+{
+	if ((n->next = e->next) != NULL)
+		n->next->pprev = &n->next;
+	else
+		hd->last = &n->next;
+	n->pprev = e->pprev;
+	*n->pprev = n;
+}
+
+void tq_concat(struct tqh *hd1, struct tqh *hd2)
+{
+	if (hd2->first != NULL) {
+		*hd1->last = hd2->first;
+		hd2->first->pprev = hd1->last;
+		hd1->last = hd2->last;
+		hd2->first = NULL;
+		hd2->last = &hd2->first;
+	}
+}
+
+void tq_cleanup(struct tqh *hd, void (*func)(void *))
+{
+	struct tqe *e, *t;
+
+	tq_foreach_safe(e, hd, t) {
+		tq_remove(hd, e);
+		if (func)
+			func(e->data);
+		free(e);
+	}
+}
+
+struct tqe *tq_find_from_data(struct tqh *hd, const void *data, int (*cmp)(const void *, const void *))
+{
+	struct tqe *e;
+
+	if (hd && !tq_empty(hd))
+		tq_foreach(e, hd)
+			if (e->data && cmp(e->data, data) == 0)
+				return e;
+
+	return NULL;
+}