latest sources commit

deps/mysqllite/include/internal/queues.h

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+/* Copyright (C) 2000 MySQL AB
+
+   This program 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; version 2 of the License.
+
+   This program 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, 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
+
+#include "my_global.h"                          /* uchar */
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+typedef struct st_queue {
+  uchar **root;
+  void *first_cmp_arg;
+  uint elements;
+  uint max_elements;
+  uint offset_to_key;	/* compare is done on element+offset */
+  int max_at_top;	/* Normally 1, set to -1 if queue_top gives max */
+  int  (*compare)(void *, uchar *,uchar *);
+  uint auto_extent;
+} 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)
+#define queue_set_cmp_arg(queue, set_arg) (queue)->first_cmp_arg= set_arg
+#define queue_set_max_at_top(queue, set_arg) \
+  (queue)->max_at_top= set_arg ? -1 : 1
+typedef int (*queue_compare)(void *,uchar *, uchar *);
+
+int init_queue(QUEUE *queue,uint max_elements,uint offset_to_key,
+	       pbool max_at_top, queue_compare compare,
+	       void *first_cmp_arg);
+int init_queue_ex(QUEUE *queue,uint max_elements,uint offset_to_key,
+	       pbool max_at_top, queue_compare compare,
+	       void *first_cmp_arg, uint auto_extent);
+int reinit_queue(QUEUE *queue,uint max_elements,uint offset_to_key,
+                 pbool max_at_top, queue_compare compare,
+                 void *first_cmp_arg);
+int resize_queue(QUEUE *queue, uint max_elements);
+void delete_queue(QUEUE *queue);
+void queue_insert(QUEUE *queue,uchar *element);
+int queue_insert_safe(QUEUE *queue, uchar *element);
+uchar *queue_remove(QUEUE *queue,uint idx);
+#define queue_remove_all(queue) { (queue)->elements= 0; }
+#define queue_is_full(queue) (queue->elements == queue->max_elements)
+void _downheap(QUEUE *queue,uint idx);
+void queue_fix(QUEUE *queue);
+#define is_queue_inited(queue) ((queue)->root != 0)
+
+#ifdef	__cplusplus
+}
+#endif
+#endif