73 lines
2.6 KiB
C
73 lines
2.6 KiB
C
/* 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
|
|
#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
|