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+/* 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