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 | 48 ++++++++++++++++++++++++++++++++++++------
1 file changed, 42 insertions(+), 6 deletions(-)
diff --git a/libsepol/src/ebitmap.c b/libsepol/src/ebitmap.c
index 0f9afd62..c9164c5e 100644
--- a/libsepol/src/ebitmap.c
+++ b/libsepol/src/ebitmap.c
@@ -101,14 +101,50 @@ int ebitmap_xor(ebitmap_t *dst, const ebitmap_t *e1, const ebitmap_t *e2)
int ebitmap_not(ebitmap_t *dst, const ebitmap_t *e1, unsigned int maxbit)
{
- unsigned int i;
+ const ebitmap_node_t *n;
+ ebitmap_node_t *new, *prev = NULL;
+ uint32_t startbit, cur_startbit;
+ MAPTYPE map;
+
ebitmap_init(dst);
- for (i=0; i < maxbit; i++) {
- int val = ebitmap_get_bit(e1, i);
- int rc = ebitmap_set_bit(dst, i, !val);
- if (rc < 0)
- return rc;
+
+ n = e1->node;
+ for (cur_startbit = 0; cur_startbit < maxbit; cur_startbit += MAPSIZE) {
+ if (n && n->startbit == cur_startbit) {
+ startbit = n->startbit;
+ map = ~n->map;
+
+ n = n->next;
+ } else {
+ startbit = cur_startbit;
+ map = ~((MAPTYPE) 0);
+ }
+
+ if (maxbit - cur_startbit < MAPSIZE)
+ map &= (((MAPTYPE)1) << (maxbit - cur_startbit)) - 1;
+
+ if (map != 0) {
+ new = malloc(sizeof(ebitmap_node_t));
+ if (!new) {
+ ebitmap_destroy(dst);
+ return -ENOMEM;
+ }
+
+ new->startbit = startbit;
+ new->map = map;
+ new->next = NULL;
+
+ if (prev)
+ prev->next = new;
+ else
+ dst->node = new;
+ prev = new;
+ }
}
+
+ if (prev)
+ dst->highbit = prev->startbit + MAPSIZE;
+
return 0;
}
--
2.36.1
