queues.h
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上传日期:2022-05-23
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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; either version 2 of the License, or
- (at your option) any later version.
- 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
- #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)
- typedef int (*queue_compare)(void *,byte *, byte *);
- int init_queue(QUEUE *queue,uint max_elements,uint offset_to_key,
- pbool max_at_top, queue_compare compare,
- void *first_cmp_arg);
- 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,byte *element);
- byte *queue_remove(QUEUE *queue,uint idx);
- void _downheap(QUEUE *queue,uint idx);
- void queue_fix(QUEUE *queue);
- #define is_queue_inited(queue) ((queue)->root != 0)
- #ifdef __cplusplus
- }
- #endif
- #endif