diff options
| -rw-r--r-- | prio-queue.c | 9 | ||||
| -rw-r--r-- | prio-queue.h | 6 | ||||
| -rw-r--r-- | t/helper/test-prio-queue.c | 26 | ||||
| -rwxr-xr-x | t/t0009-prio-queue.sh | 14 |
4 files changed, 47 insertions, 8 deletions
diff --git a/prio-queue.c b/prio-queue.c index a078451872..d3f488cb05 100644 --- a/prio-queue.c +++ b/prio-queue.c @@ -85,3 +85,12 @@ void *prio_queue_get(struct prio_queue *queue) } return result; } + +void *prio_queue_peek(struct prio_queue *queue) +{ + if (!queue->nr) + return NULL; + if (!queue->compare) + return queue->array[queue->nr - 1].data; + return queue->array[0].data; +} diff --git a/prio-queue.h b/prio-queue.h index d030ec9dd6..682e51867a 100644 --- a/prio-queue.h +++ b/prio-queue.h @@ -46,6 +46,12 @@ extern void prio_queue_put(struct prio_queue *, void *thing); */ extern void *prio_queue_get(struct prio_queue *); +/* + * Gain access to the "thing" that would be returned by + * prio_queue_get, but do not remove it from the queue. + */ +extern void *prio_queue_peek(struct prio_queue *); + extern void clear_prio_queue(struct prio_queue *); /* Reverse the LIFO elements */ diff --git a/t/helper/test-prio-queue.c b/t/helper/test-prio-queue.c index 9807b649b1..5bc9c46ea5 100644 --- a/t/helper/test-prio-queue.c +++ b/t/helper/test-prio-queue.c @@ -22,14 +22,24 @@ int cmd__prio_queue(int argc, const char **argv) struct prio_queue pq = { intcmp }; while (*++argv) { - if (!strcmp(*argv, "get")) - show(prio_queue_get(&pq)); - else if (!strcmp(*argv, "dump")) { - int *v; - while ((v = prio_queue_get(&pq))) - show(v); - } - else { + 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); diff --git a/t/t0009-prio-queue.sh b/t/t0009-prio-queue.sh index e56dfce668..3941ad2528 100755 --- a/t/t0009-prio-queue.sh +++ b/t/t0009-prio-queue.sh @@ -47,4 +47,18 @@ test_expect_success 'notice empty queue' ' test_cmp expect actual ' +cat >expect <<'EOF' +3 +2 +6 +4 +5 +1 +8 +EOF +test_expect_success 'stack order' ' + test-tool prio-queue stack 8 1 5 4 6 2 3 dump >actual && + test_cmp expect actual +' + test_done |