1 files changed, 126 insertions, 0 deletions
diff --git a/lib/dpkg/pkg-queue.c b/lib/dpkg/pkg-queue.c
new file mode 100644
index 0000000..a807f1e
--- /dev/null
+++ b/lib/dpkg/pkg-queue.c
@@ -0,0 +1,126 @@
+/*
+ * libdpkg - Debian packaging suite library routines
+ * pkg-queue.c - primitives for pkg queue handling
+ *
+ * Copyright © 2010 Guillem Jover <guillem@debian.org>
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <compat.h>
+
+#include <stdlib.h>
+
+#include <dpkg/dpkg-db.h>
+#include <dpkg/pkg-queue.h>
+
+/**
+ * Initialize a package queue.
+ *
+ * @param queue The queue to initialize.
+ */
+void
+pkg_queue_init(struct pkg_queue *queue)
+{
+	queue->head = NULL;
+	queue->tail = NULL;
+	queue->length = 0;
+}
+
+/**
+ * Destroy a package queue.
+ *
+ * It frees the contained package list and resets the queue members.
+ *
+ * @param queue The queue to destroy.
+ */
+void
+pkg_queue_destroy(struct pkg_queue *queue)
+{
+	pkg_list_free(queue->head);
+	pkg_queue_init(queue);
+}
+
+/**
+ * Check if a package queue is empty.
+ *
+ * @param queue The queue to check.
+ *
+ * @return A boolean value.
+ */
+int
+pkg_queue_is_empty(struct pkg_queue *queue)
+{
+	return (queue->head == NULL);
+}
+
+/**
+ * Push a new node containing pkginfo to the tail of the queue.
+ *
+ * @param queue The queue to insert to.
+ * @param pkg The package to use fo the new node.
+ *
+ * @return The newly inserted pkg_list node.
+ */
+struct pkg_list *
+pkg_queue_push(struct pkg_queue *queue, struct pkginfo *pkg)
+{
+	struct pkg_list *node;
+
+	node = pkg_list_new(pkg, NULL);
+
+	if (queue->tail == NULL)
+		queue->head = node;
+	else
+		queue->tail->next = node;
+
+	queue->tail = node;
+
+	queue->length++;
+
+	return node;
+}
+
+/**
+ * Pop a node containing pkginfo from the head of the queue.
+ *
+ * This removes and frees the node from the queue, effectively reducing its
+ * size.
+ *
+ * @param queue The queue to remove from.
+ *
+ * @return The pkginfo from the removed node, or NULL if the queue was empty.
+ */
+struct pkginfo *
+pkg_queue_pop(struct pkg_queue *queue)
+{
+	struct pkg_list *node;
+	struct pkginfo *pkg;
+
+	if (pkg_queue_is_empty(queue))
+		return NULL;
+
+	node = queue->head;
+	pkg = node->pkg;
+
+	queue->head = node->next;
+	if (queue->head == NULL)
+		queue->tail = NULL;
+
+	free(node);
+	queue->length--;
+
+	return pkg;
+}