Add an initializer for ebitmaps that sets all bits in a given range to
save node traversals for each bit to set, compared to calling
ebitmap_init() followed by iterating ebitmap_set_bit().
Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
---
v2:
use braces for all if-else branches when used for at least one of them
---
libsepol/include/sepol/policydb/ebitmap.h | 1 +
libsepol/src/ebitmap.c | 49 +++++++++++++++++++++++
libsepol/tests/test-ebitmap.c | 32 +++++++++++++++
3 files changed, 82 insertions(+)
diff --git a/libsepol/include/sepol/policydb/ebitmap.h b/libsepol/include/sepol/policydb/ebitmap.h
index 81d0c7a6..85b7ccfb 100644
--- a/libsepol/include/sepol/policydb/ebitmap.h
+++ b/libsepol/include/sepol/policydb/ebitmap.h
@@ -94,6 +94,7 @@ extern int ebitmap_contains(const ebitmap_t * e1, const ebitmap_t * e2);
extern int ebitmap_match_any(const ebitmap_t *e1, const ebitmap_t *e2);
extern int ebitmap_get_bit(const ebitmap_t * e, unsigned int bit);
extern int ebitmap_set_bit(ebitmap_t * e, unsigned int bit, int value);
+extern int ebitmap_init_range(ebitmap_t * e, unsigned int minbit, unsigned int maxbit);
extern unsigned int ebitmap_highest_set_bit(const ebitmap_t * e);
extern void ebitmap_destroy(ebitmap_t * e);
extern int ebitmap_read(ebitmap_t * e, void *fp);
diff --git a/libsepol/src/ebitmap.c b/libsepol/src/ebitmap.c
index bd98c0f8..0f9afd62 100644
--- a/libsepol/src/ebitmap.c
+++ b/libsepol/src/ebitmap.c
@@ -349,6 +349,55 @@ int ebitmap_set_bit(ebitmap_t * e, unsigned int bit, int value)
return 0;
}
+int ebitmap_init_range(ebitmap_t * e, unsigned int minbit, unsigned int maxbit)
+{
+ ebitmap_node_t *new, *prev = NULL;
+ uint32_t minstartbit = minbit & ~(MAPSIZE - 1);
+ uint32_t maxstartbit = maxbit & ~(MAPSIZE - 1);
+ uint32_t minhighbit = minstartbit + MAPSIZE;
+ uint32_t maxhighbit = maxstartbit + MAPSIZE;
+ uint32_t startbit;
+ MAPTYPE mask;
+
+ ebitmap_init(e);
+
+ if (minbit > maxbit)
+ return -EINVAL;
+
+ if (minhighbit == 0 || maxhighbit == 0)
+ return -EOVERFLOW;
+
+ for (startbit = minstartbit; startbit <= maxstartbit; startbit += MAPSIZE) {
+ new = malloc(sizeof(ebitmap_node_t));
+ if (!new)
+ return -ENOMEM;
+
+ new->next = NULL;
+ new->startbit = startbit;
+
+ if (startbit != minstartbit && startbit != maxstartbit) {
+ new->map = ~((MAPTYPE)0);
+ } else if (startbit != maxstartbit) {
+ new->map = ~((MAPTYPE)0) << (minbit - startbit);
+ } else if (startbit != minstartbit) {
+ new->map = ~((MAPTYPE)0) >> (MAPSIZE - (maxbit - startbit + 1));
+ } else {
+ mask = ~((MAPTYPE)0) >> (MAPSIZE - (maxbit - minbit + 1));
+ new->map = (mask << (minbit - startbit));
+ }
+
+ if (prev)
+ prev->next = new;
+ else
+ e->node = new;
+ prev = new;
+ }
+
+ e->highbit = maxhighbit;
+
+ return 0;
+}
+
unsigned int ebitmap_highest_set_bit(const ebitmap_t * e)
{
const ebitmap_node_t *n;
diff --git a/libsepol/tests/test-ebitmap.c b/libsepol/tests/test-ebitmap.c
index fad5bd75..8774555e 100644
--- a/libsepol/tests/test-ebitmap.c
+++ b/libsepol/tests/test-ebitmap.c
@@ -253,6 +253,37 @@ static void test_ebitmap_set_and_get(void)
ebitmap_destroy(&e);
}
+static void test_ebitmap_init_range(void)
+{
+ ebitmap_t e1, e2, e3, e4, e5, e6;
+
+ CU_ASSERT_EQUAL(ebitmap_init_range(&e1, 0, 0), 0);
+ CU_ASSERT_EQUAL(ebitmap_highest_set_bit(&e1), 0);
+ CU_ASSERT_EQUAL(ebitmap_cardinality(&e1), 1);
+
+ CU_ASSERT_EQUAL(ebitmap_init_range(&e2, 0, 5), 0);
+ CU_ASSERT_EQUAL(ebitmap_highest_set_bit(&e2), 5);
+ CU_ASSERT_EQUAL(ebitmap_cardinality(&e2), 6);
+
+ CU_ASSERT_EQUAL(ebitmap_init_range(&e3, 20, 100), 0);
+ CU_ASSERT_EQUAL(ebitmap_highest_set_bit(&e3), 100);
+ CU_ASSERT_EQUAL(ebitmap_cardinality(&e3), 81);
+
+ CU_ASSERT_EQUAL(ebitmap_init_range(&e4, 100, 400), 0);
+ CU_ASSERT_EQUAL(ebitmap_highest_set_bit(&e4), 400);
+ CU_ASSERT_EQUAL(ebitmap_cardinality(&e4), 301);
+
+ CU_ASSERT_EQUAL(ebitmap_init_range(&e5, 10, 5), -EINVAL);
+ CU_ASSERT_EQUAL(ebitmap_init_range(&e6, 0, UINT32_MAX), -EOVERFLOW);
+
+ ebitmap_destroy(&e6);
+ ebitmap_destroy(&e5);
+ ebitmap_destroy(&e4);
+ ebitmap_destroy(&e3);
+ ebitmap_destroy(&e2);
+ ebitmap_destroy(&e1);
+}
+
static void test_ebitmap_or(void)
{
ebitmap_t e1, e2, e3, e4;
@@ -1038,6 +1069,7 @@ int ebitmap_add_tests(CU_pSuite suite)
ADD_TEST(ebitmap_init_destroy);
ADD_TEST(ebitmap_cmp);
ADD_TEST(ebitmap_set_and_get);
+ ADD_TEST(ebitmap_init_range);
ADD_TEST(ebitmap_or);
ADD_TEST(ebitmap_and);
ADD_TEST(ebitmap_xor);
--
2.36.1
