bootstrap: update tarfs driver with libfs support

sys/bootstrap/queue.c

@@ -0,0 +1,138 @@
+#include "queue.h"
+
+size_t queue_length(struct queue *q)
+{
+	size_t i = 0;
+	struct queue_entry *x = q->q_first;
+	while (x) {
+		i++;
+		x = x->qe_next;
+	}
+
+	return i;
+}
+
+void queue_insert_before(
+	struct queue *q,
+	struct queue_entry *entry,
+	struct queue_entry *before)
+{
+	struct queue_entry *x = before->qe_prev;
+	if (x) {
+		x->qe_next = entry;
+	} else {
+		q->q_first = entry;
+	}
+
+	entry->qe_prev = x;
+
+	before->qe_prev = entry;
+	entry->qe_next = before;
+}
+
+void queue_insert_after(
+	struct queue *q,
+	struct queue_entry *entry,
+	struct queue_entry *after)
+{
+	struct queue_entry *x = after->qe_next;
+	if (x) {
+		x->qe_prev = entry;
+	} else {
+		q->q_last = entry;
+	}
+
+	entry->qe_prev = x;
+
+	after->qe_next = entry;
+	entry->qe_prev = after;
+}
+
+void queue_push_front(struct queue *q, struct queue_entry *entry)
+{
+	if (q->q_first) {
+		q->q_first->qe_prev = entry;
+	}
+
+	entry->qe_next = q->q_first;
+	entry->qe_prev = NULL;
+
+	q->q_first = entry;
+
+	if (!q->q_last) {
+		q->q_last = entry;
+	}
+}
+
+void queue_push_back(struct queue *q, struct queue_entry *entry)
+{
+	if (q->q_last) {
+		q->q_last->qe_next = entry;
+	}
+
+	entry->qe_prev = q->q_last;
+	entry->qe_next = NULL;
+
+	q->q_last = entry;
+
+	if (!q->q_first) {
+		q->q_first = entry;
+	}
+}
+
+struct queue_entry *queue_pop_front(struct queue *q)
+{
+	struct queue_entry *x = q->q_first;
+	if (x) {
+		queue_delete(q, x);
+	}
+
+	return x;
+}
+
+struct queue_entry *queue_pop_back(struct queue *q)
+{
+	struct queue_entry *x = q->q_last;
+	if (x) {
+		queue_delete(q, x);
+	}
+
+	return x;
+}
+
+void queue_delete(struct queue *q, struct queue_entry *entry)
+{
+	if (!entry) {
+		return;
+	}
+
+	if (entry == q->q_first) {
+		q->q_first = q->q_first->qe_next;
+	}
+
+	if (entry == q->q_last) {
+		q->q_last = q->q_last->qe_prev;
+	}
+
+	if (entry->qe_next) {
+		entry->qe_next->qe_prev = entry->qe_prev;
+	}
+
+	if (entry->qe_prev) {
+		entry->qe_prev->qe_next = entry->qe_next;
+	}
+
+	entry->qe_next = entry->qe_prev = NULL;
+}
+
+void queue_delete_all(struct queue *q)
+{
+	struct queue_entry *x = q->q_first;
+	while (x) {
+		struct queue_entry *next = x->qe_next;
+		x->qe_next = x->qe_prev = NULL;
+		x = next;
+	}
+
+	q->q_first = q->q_last = NULL;
+}