bitmap: implement bitmap_is_subset()

The bitmap_is_subset() function checks if the 'self' bitmap contains any
bitmaps that are not on in the 'other' bitmap. Up until this patch, it
had a declaration, but no implementation or callers. A subsequent patch
will want this function, so implement it here.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Derrick Stolee 2020-12-08 17:04:08 -05:00 committed by Junio C Hamano
parent 6dc5ef759f
commit ed03a58b65
2 changed files with 22 additions and 1 deletions

View File

@ -195,6 +195,27 @@ int bitmap_equals(struct bitmap *self, struct bitmap *other)
return 1;
}
int bitmap_is_subset(struct bitmap *self, struct bitmap *other)
{
size_t common_size, i;
if (self->word_alloc < other->word_alloc)
common_size = self->word_alloc;
else {
common_size = other->word_alloc;
for (i = common_size; i < self->word_alloc; i++) {
if (self->words[i])
return 1;
}
}
for (i = 0; i < common_size; i++) {
if (self->words[i] & ~other->words[i])
return 1;
}
return 0;
}
void bitmap_reset(struct bitmap *bitmap)
{
memset(bitmap->words, 0x0, bitmap->word_alloc * sizeof(eword_t));

View File

@ -180,7 +180,7 @@ int bitmap_get(struct bitmap *self, size_t pos);
void bitmap_reset(struct bitmap *self);
void bitmap_free(struct bitmap *self);
int bitmap_equals(struct bitmap *self, struct bitmap *other);
int bitmap_is_subset(struct bitmap *self, struct bitmap *super);
int bitmap_is_subset(struct bitmap *self, struct bitmap *other);
struct ewah_bitmap * bitmap_to_ewah(struct bitmap *bitmap);
struct bitmap *ewah_to_bitmap(struct ewah_bitmap *ewah);