Import changeset

1 files changed, 57 insertions, 0 deletions

diff --git a/include/queues.h b/include/queues.h
new file mode 100644
index 00000000000..99001bfbf6d
--- /dev/null
+++ b/include/queues.h
@@ -0,0 +1,57 @@
+/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
+   
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public
+   License as published by the Free Software Foundation; either
+   version 2 of the License, or (at your option) any later version.
+   
+   This library 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
+   Library General Public License for more details.
+   
+   You should have received a copy of the GNU Library General Public
+   License along with this library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+   MA 02111-1307, USA */
+
+/*
+  Code for generell handling of priority Queues.
+  Implemention of queues from "Algoritms in C" by Robert Sedgewick.
+  Copyright Monty Program KB.
+  By monty.
+*/
+
+#ifndef _queues_h
+#define _queues_h
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+typedef struct st_queue {
+  byte **root;
+  void *first_cmp_arg;
+  uint elements;
+  uint max_elements;
+  uint offset_to_key;			/* compare is done on element+offset */
+  int max_at_top;			/* Set if queue_top gives max */
+  int  (*compare)(void *, byte *,byte *);
+} QUEUE;
+
+#define queue_top(queue) ((queue)->root[1])
+#define queue_element(queue,index) ((queue)->root[index+1])
+#define queue_end(queue) ((queue)->root[(queue)->elements])
+#define queue_replaced(queue) _downheap(queue,1)
+
+int init_queue(QUEUE *queue,uint max_elements,uint offset_to_key,
+	       pbool max_at_top, int (*compare)(void *,byte *, byte *),
+	       void *first_cmp_arg);
+void delete_queue(QUEUE *queue);
+void queue_insert(QUEUE *queue,byte *element);
+byte *queue_remove(QUEUE *queue,uint idx);
+void _downheap(QUEUE *queue,uint idx);
+
+#ifdef	__cplusplus
+}
+#endif
+#endif