git/t/helper/test-prio-queue.c
Derrick Stolee aca4240f6a prio-queue: add 'peek' operation
When consuming a priority queue, it can be convenient to inspect
the next object that will be dequeued without actually dequeueing
it. Our existing library did not have such a 'peek' operation, so
add it as prio_queue_peek().

Add a reference-level comparison in t/helper/test-prio-queue.c
so this method is exercised by t0009-prio-queue.sh. Further, add
a test that checks the behavior when the compare function is NULL
(i.e. the queue becomes a stack).

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-02 12:14:21 +09:00

50 lines
973 B
C

#include "test-tool.h"
#include "cache.h"
#include "prio-queue.h"
static int intcmp(const void *va, const void *vb, void *data)
{
const int *a = va, *b = vb;
return *a - *b;
}
static void show(int *v)
{
if (!v)
printf("NULL\n");
else
printf("%d\n", *v);
free(v);
}
int cmd__prio_queue(int argc, const char **argv)
{
struct prio_queue pq = { intcmp };
while (*++argv) {
if (!strcmp(*argv, "get")) {
void *peek = prio_queue_peek(&pq);
void *get = prio_queue_get(&pq);
if (peek != get)
BUG("peek and get results do not match");
show(get);
} else if (!strcmp(*argv, "dump")) {
void *peek;
void *get;
while ((peek = prio_queue_peek(&pq))) {
get = prio_queue_get(&pq);
if (peek != get)
BUG("peek and get results do not match");
show(get);
}
} else if (!strcmp(*argv, "stack")) {
pq.compare = NULL;
} else {
int *v = malloc(sizeof(*v));
*v = atoi(*argv);
prio_queue_put(&pq, v);
}
}
return 0;
}