void *bt_heap_remove(struct ptr_heap *heap)
{
switch (heap->len) {
case 0:
return NULL;
case 1:
(void) heap_set_len(heap, 0);
return heap->ptrs[0];
}
/* Shrink, replace the current max by previous last entry and heapify */
heap_set_len(heap, heap->len - 1);
/* len changed. previous last entry is at heap->len */
return bt_heap_replace_max(heap, heap->ptrs[heap->len]);
}
void *bt_heap_cherrypick(struct ptr_heap *heap, void *p)
{
size_t pos, len = heap->len;
for (pos = 0; pos < len; pos++)
if (unlikely(heap->ptrs[pos] == p))
goto found;
return NULL;
found:
if (unlikely(heap->len == 1)) {
(void) heap_set_len(heap, 0);
check_heap(heap);
return heap->ptrs[0];
}
/* Replace p with previous last entry and heapify. */
heap_set_len(heap, heap->len - 1);
/* len changed. previous last entry is at heap->len */
heap->ptrs[pos] = heap->ptrs[heap->len];
heapify(heap, pos);
return p;
}
int bt_heap_copy(struct ptr_heap *dst, struct ptr_heap *src)
{
int ret;
ret = bt_heap_init(dst, src->alloc_len, src->gt);
if (ret < 0)
goto end;
ret = heap_set_len(dst, src->len);
if (ret < 0)
goto end;
memcpy(dst->ptrs, src->ptrs, src->len * sizeof(void *));
end:
return ret;
}
void *bt_heap_replace_max(struct ptr_heap *heap, void *p)
{
void *res;
if (unlikely(!heap->len)) {
(void) heap_set_len(heap, 1);
heap->ptrs[0] = p;
check_heap(heap);
return NULL;
}
/* Replace the current max and heapify */
res = heap->ptrs[0];
heap->ptrs[0] = p;
heapify(heap, 0);
return res;
}
void *lttng_heap_replace_max(struct lttng_ptr_heap *heap, void *p)
{
void *res;
if (!heap->len) {
(void) heap_set_len(heap, 1);
heap->ptrs[0] = p;
lttng_check_heap(heap);
return NULL;
}
/* Replace the current max and heapify */
res = heap->ptrs[0];
heap->ptrs[0] = p;
heapify(heap, 0);
return res;
}
int bt_heap_insert(struct ptr_heap *heap, void *p)
{
void **ptrs;
size_t pos;
int ret;
ret = heap_set_len(heap, heap->len + 1);
if (unlikely(ret))
return ret;
ptrs = heap->ptrs;
pos = heap->len - 1;
while (pos > 0 && heap->gt(p, ptrs[parent(pos)])) {
/* Move parent down until we find the right spot */
ptrs[pos] = ptrs[parent(pos)];
pos = parent(pos);
}
ptrs[pos] = p;
check_heap(heap);
return 0;
}
