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Diffstat (limited to 'include/queues.h')
-rw-r--r-- | include/queues.h | 57 |
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 |