On Tue, Jul 12, 2022 at 12:09 PM Christian Göttsche
<cgzones@xxxxxxxxxxxxxx> wrote:
>
> Iterate on nodes instead of single bits to save node resolution for each
> single bit.
>
> Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
> ---
> libsepol/src/ebitmap.c | 42 +++++++++++++++++++++++++++++++++++-------
> 1 file changed, 35 insertions(+), 7 deletions(-)
>
> diff --git a/libsepol/src/ebitmap.c b/libsepol/src/ebitmap.c
> index 6a63e559..c3d706e9 100644
> --- a/libsepol/src/ebitmap.c
> +++ b/libsepol/src/ebitmap.c
> @@ -74,15 +74,43 @@ int ebitmap_union(ebitmap_t * dst, const ebitmap_t * e1)
>
> int ebitmap_and(ebitmap_t *dst, const ebitmap_t *e1, const ebitmap_t *e2)
> {
> - unsigned int i, length = min(ebitmap_length(e1), ebitmap_length(e2));
> + const ebitmap_node_t *n1, *n2;
> + ebitmap_node_t *new, *prev = NULL;
> +
> ebitmap_init(dst);
> - for (i=0; i < length; i++) {
> - if (ebitmap_get_bit(e1, i) && ebitmap_get_bit(e2, i)) {
> - int rc = ebitmap_set_bit(dst, i, 1);
> - if (rc < 0)
> - return rc;
> - }
> +
> + n1 = e1->node;
> + n2 = e2->node;
> + while (n1 && n2) {
> + if (n1->startbit == n2->startbit) {
> + if (n1->map & n2->map) {
> + new = malloc(sizeof(ebitmap_node_t));
> + if (!new) {
> + ebitmap_destroy(dst);
> + return -ENOMEM;
> + }
> + new->startbit = n1->startbit;
> + new->map = n1->map & n2->map;
> + new->next = NULL;
> +
> + if (prev)
> + prev->next = new;
> + else
> + dst->node = new;
> + prev = new;
> + }
> +
> + n1 = n1->next;
> + n2 = n2->next;
> + } else if (n1->startbit > n2->startbit)
> + n2 = n2->next;
> + else
> + n1 = n1->next;
I would like to see braces around the last two clauses.
Thanks,
Jim
> }
> +
> + if (prev)
> + dst->highbit = prev->startbit + MAPSIZE;
> +
> return 0;
> }
>
> --
> 2.36.1
>
