initial commit

core/queue.c

@@ -0,0 +1,196 @@
+#include <blue/core/queue.h>
+
+size_t b_queue_length(struct b_queue *q)
+{
+	size_t i = 0;
+	struct b_queue_entry *x = q->q_first;
+	while (x) {
+		i++;
+		x = x->qe_next;
+	}
+
+	return i;
+}
+
+void b_queue_insert_before(
+	struct b_queue *q, struct b_queue_entry *entry, struct b_queue_entry *before)
+{
+	struct b_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 b_queue_insert_after(
+	struct b_queue *q, struct b_queue_entry *entry, struct b_queue_entry *after)
+{
+	struct b_queue_entry *x = after->qe_next;
+	if (x) {
+		x->qe_prev = entry;
+	} else {
+		q->q_last = entry;
+	}
+
+	entry->qe_next = x;
+
+	after->qe_next = entry;
+	entry->qe_prev = after;
+}
+
+void b_queue_push_front(struct b_queue *q, struct b_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 b_queue_push_back(struct b_queue *q, struct b_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 b_queue_entry *b_queue_pop_front(struct b_queue *q)
+{
+	struct b_queue_entry *x = q->q_first;
+	if (x) {
+		b_queue_delete(q, x);
+	}
+
+	return x;
+}
+
+struct b_queue_entry *b_queue_pop_back(struct b_queue *q)
+{
+	struct b_queue_entry *x = q->q_last;
+	if (x) {
+		b_queue_delete(q, x);
+	}
+
+	return x;
+}
+
+void b_queue_delete(struct b_queue *q, struct b_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 b_queue_delete_all(struct b_queue *q)
+{
+	struct b_queue_entry *x = q->q_first;
+	while (x) {
+		struct b_queue_entry *next = x->qe_next;
+		x->qe_next = x->qe_prev = NULL;
+		x = next;
+	}
+
+	q->q_first = q->q_last = NULL;
+}
+
+static bool queue_iterator_next(struct b_iterator *it)
+{
+	return b_queue_iterator_next((struct b_queue_iterator *)it);
+}
+
+static b_status queue_iterator_erase(struct b_iterator *it)
+{
+	return b_queue_iterator_erase((struct b_queue_iterator *)it);
+}
+
+static bool queue_iterator_is_valid(const struct b_iterator *it)
+{
+	return b_queue_iterator_is_valid((const struct b_queue_iterator *)it);
+}
+
+static const b_iterator_ops queue_iterator_ops = {
+	.it_next = queue_iterator_next,
+	.it_erase = queue_iterator_erase,
+	.it_close = NULL,
+	.it_is_valid = queue_iterator_is_valid,
+};
+
+int b_queue_iterator_begin(const struct b_queue *q, struct b_queue_iterator *it)
+{
+	it->_q = (struct b_queue *)q;
+	it->_base.it_ops = &queue_iterator_ops;
+	it->entry = q->q_first;
+	it->i = 0;
+
+	return 0;
+}
+
+bool b_queue_iterator_next(struct b_queue_iterator *it)
+{
+	if (!it->entry) {
+		return false;
+	}
+
+	it->entry = it->entry->qe_next;
+	it->i++;
+
+	return it->entry != NULL;
+}
+
+b_status b_queue_iterator_erase(struct b_queue_iterator *it)
+{
+	if (!it->entry) {
+		return B_ERR_OUT_OF_BOUNDS;
+	}
+
+	struct b_queue_entry *next = it->entry->qe_next;
+	b_queue_delete(it->_q, it->entry);
+	it->entry = next;
+
+	return B_SUCCESS;
+}
+
+bool b_queue_iterator_is_valid(const struct b_queue_iterator *it)
+{
+	return it->entry != NULL;
+}