1 files changed, 110 insertions, 0 deletions
diff --git a/libqueue/queue/sq.c b/libqueue/queue/sq.c
new file mode 100644
index 0000000..66b396a
--- /dev/null
+++ b/libqueue/queue/sq.c
@@ -0,0 +1,110 @@
+/* vim: set ts=4 sw=4 ai:
+ * sq.c -- simple queue implementation derived from NetBSD's queue.h
+ */
+
+#include <stdlib.h>
+#include "sq.h"
+
+struct sqh *sq_new(void)
+{
+	struct sqh *hd;
+
+	hd = malloc(sizeof(*hd));
+	if (hd != NULL)
+		sq_init(hd);
+
+	return hd;
+}
+
+struct sqe *sq_elem_new(void *data)
+{
+	struct sqe *e;
+
+	e = malloc(sizeof(*e));
+	if (e != NULL)
+		e->data = data;
+
+	return e;
+}
+
+void sq_insert_head(struct sqh *hd, struct sqe *e)
+{
+	if ((e->next = hd->first) == NULL)
+		hd->last = &e->next;
+		
+	hd->first = e;
+}
+
+void sq_insert_tail(struct sqh *hd, struct sqe *e)
+{
+	e->next = NULL;
+	*hd->last = e;
+	hd->last = &e->next;
+}
+
+void sq_insert_after(struct sqh *hd, struct sqe *e, struct sqe *n)
+{
+	if ((n->next = e->next) == NULL)
+		hd->last = &n->next;
+	e->next = n;
+}
+
+void sq_remove_head(struct sqh *hd)
+{
+	if ((hd->first = hd->first->next) == NULL)
+		hd->last = &hd->first;
+}
+
+void sq_remove_after(struct sqh *hd, struct sqe *e)
+{
+	if ((e->next = e->next->next) == NULL)
+		hd->last = &e->next;
+}
+
+void sq_remove(struct sqh *hd, struct sqe *e)
+{
+	if (hd->first == e) {
+		if ((hd->first = hd->first->next) == NULL)
+			hd->last = &hd->first;
+	}
+	else {
+		struct sqe *cur = hd->first;
+		while (cur->next != e)
+			cur = cur->next;
+		if ((cur->next = cur->next->next) == NULL)
+			hd->last = &cur->next;
+	}
+}
+
+void sq_concat(struct sqh *hd1, struct sqh *hd2)
+{
+	if (!(hd2->first == NULL)) {
+		*hd1->last = hd2->first;
+		hd1->last = hd2->last;
+		hd2->first = NULL;
+		hd2->last = &hd2->first;
+	}
+}
+
+void sq_cleanup(struct sqh *hd, void (*func)(void *))
+{
+	struct sqe *e, *t;
+
+	sq_foreach_safe(e, hd, t) {
+		sq_remove(hd, e);
+		if (func)
+			func(e->data);
+		free(e);
+	}
+}
+struct sqe *sq_find_from_data(struct sqh *hd, const void *data, int (*cmp)(const void *, const void *))
+{
+	struct sqe *e;
+
+	if (hd && !sq_empty(hd))
+		sq_foreach(e, hd)
+			if (e->data && cmp(e->data, data) == 0)
+				return e;
+
+	return NULL;
+}