diff options
Diffstat (limited to 'mysys/queues.c')
| -rw-r--r-- | mysys/queues.c | 69 |
1 files changed, 60 insertions, 9 deletions
diff --git a/mysys/queues.c b/mysys/queues.c index 93d4c303f22..ecf1058af41 100644 --- a/mysys/queues.c +++ b/mysys/queues.c @@ -24,7 +24,26 @@ #include <queues.h> -/* Init queue */ +/* + Init queue + + SYNOPSIS + init_queue() + queue Queue to initialise + max_elements Max elements that will be put in queue + offset_to_key Offset to key in element stored in queue + Used when sending pointers to compare function + max_at_top Set to 1 if you want biggest element on top. + compare Compare function for elements, takes 3 arguments. + first_cmp_arg First argument to compare function + + NOTES + Will allocate max_element pointers for queue array + + RETURN + 0 ok + 1 Could not allocate memory +*/ int init_queue(QUEUE *queue, uint max_elements, uint offset_to_key, pbool max_at_top, int (*compare) (void *, byte *, byte *), @@ -43,13 +62,32 @@ int init_queue(QUEUE *queue, uint max_elements, uint offset_to_key, DBUG_RETURN(0); } + /* - Reinitialize queue for new usage; + Reinitialize queue for other usage + + SYNOPSIS + reinit_queue() + queue Queue to initialise + max_elements Max elements that will be put in queue + offset_to_key Offset to key in element stored in queue + Used when sending pointers to compare function + max_at_top Set to 1 if you want biggest element on top. + compare Compare function for elements, takes 3 arguments. + first_cmp_arg First argument to compare function + + NOTES + This will delete all elements from the queue. If you don't want this, + use resize_queue() instead. + + RETURN + 0 ok + EE_OUTOFMEMORY Wrong max_elements */ int reinit_queue(QUEUE *queue, uint max_elements, uint offset_to_key, - pbool max_at_top, int (*compare) (void *, byte *, byte *), - void *first_cmp_arg) + pbool max_at_top, int (*compare) (void *, byte *, byte *), + void *first_cmp_arg) { DBUG_ENTER("reinit_queue"); queue->elements=0; @@ -96,6 +134,20 @@ int resize_queue(QUEUE *queue, uint max_elements) } +/* + Delete queue + + SYNOPSIS + delete_queue() + queue Queue to delete + + IMPLEMENTATION + Just free allocated memory. + + NOTES + Can be called safely multiple times +*/ + void delete_queue(QUEUE *queue) { DBUG_ENTER("delete_queue"); @@ -146,7 +198,7 @@ byte *queue_remove(register QUEUE *queue, uint idx) return 0; #endif { - byte *element=queue->root[++idx]; /* Intern index starts from 1 */ + byte *element=queue->root[++idx]; /* Intern index starts from 1 */ queue->root[idx]=queue->root[queue->elements--]; _downheap(queue,idx); return element; @@ -156,8 +208,7 @@ byte *queue_remove(register QUEUE *queue, uint idx) /* Fix when element on top has been replaced */ #ifndef queue_replaced -void queue_replaced(queue) -QUEUE *queue; +void queue_replaced(QUEUE *queue) { _downheap(queue,1); } @@ -199,8 +250,8 @@ void _downheap(register QUEUE *queue, uint idx) static int queue_fix_cmp(QUEUE *queue, void **a, void **b) { return queue->compare(queue->first_cmp_arg, - (char*) (*a)+queue->offset_to_key, - (char*) (*b)+queue->offset_to_key); + (byte*) (*a)+queue->offset_to_key, + (byte*) (*b)+queue->offset_to_key); } /* |