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#include "cache.h"
#include "commit.h"
#include "prio-queue.h"
void prio_queue_reverse(struct prio_queue *queue)
{
int i, j;
if (queue->compare != NULL)
die("BUG: prio_queue_reverse() on non-LIFO queue");
for (i = 0; i <= (j = (queue->nr - 1) - i); i++) {
struct commit *swap = queue->array[i];
queue->array[i] = queue->array[j];
queue->array[j] = swap;
}
}
void clear_prio_queue(struct prio_queue *queue)
{
free(queue->array);
queue->nr = 0;
queue->alloc = 0;
queue->array = NULL;
}
void prio_queue_put(struct prio_queue *queue, void *thing)
{
prio_queue_compare_fn compare = queue->compare;
int ix, parent;
/* Append at the end */
ALLOC_GROW(queue->array, queue->nr + 1, queue->alloc);
queue->array[queue->nr++] = thing;
if (!compare)
return; /* LIFO */
/* Bubble up the new one */
for (ix = queue->nr - 1; ix; ix = parent) {
parent = (ix - 1) / 2;
if (compare(queue->array[parent], queue->array[ix],
queue->cb_data) <= 0)
break;
thing = queue->array[parent];
queue->array[parent] = queue->array[ix];
queue->array[ix] = thing;
}
}
void *prio_queue_get(struct prio_queue *queue)
{
void *result, *swap;
int ix, child;
prio_queue_compare_fn compare = queue->compare;
if (!queue->nr)
return NULL;
if (!compare)
return queue->array[--queue->nr]; /* LIFO */
result = queue->array[0];
if (!--queue->nr)
return result;
queue->array[0] = queue->array[queue->nr];
/* Push down the one at the root */
for (ix = 0; ix * 2 + 1 < queue->nr; ix = child) {
child = ix * 2 + 1; /* left */
if ((child + 1 < queue->nr) &&
(compare(queue->array[child], queue->array[child + 1],
queue->cb_data) >= 0))
child++; /* use right child */
if (compare(queue->array[ix], queue->array[child],
queue->cb_data) <= 0)
break;
swap = queue->array[child];
queue->array[child] = queue->array[ix];
queue->array[ix] = swap;
}
return result;
}
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