X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Ftag.c;h=13d182925eb3f5a0f4570a8fb717efb3035a5bcf;hb=28c5588e8e1a8d091c5d2275232c35f2968a97fa;hp=b45bcd55d2bf7ce96814bbe9ccafb8d8715503a4;hpb=b63e3bbc18c459073a4b83a26b17c53f34f3dcf2;p=sliver-openvswitch.git

diff --git a/lib/tag.c b/lib/tag.c
index b45bcd55d..13d182925 100644
--- a/lib/tag.c
+++ b/lib/tag.c
@@ -16,10 +16,6 @@
 
 #include <config.h>
 #include "tag.h"
-#include <limits.h>
-
-#define N_TAG_BITS (CHAR_BIT * sizeof(tag_type))
-BUILD_ASSERT_DECL(IS_POW2(N_TAG_BITS));
 
 #define LOG2_N_TAG_BITS (N_TAG_BITS == 32 ? 5 : N_TAG_BITS == 64 ? 6 : 0)
 BUILD_ASSERT_DECL(LOG2_N_TAG_BITS > 0);
@@ -37,3 +33,32 @@ tag_create_deterministic(uint32_t seed)
     y += y >= x;
     return (1u << x) | (1u << y);
 }
+
+/* Initializes 'tracker'. */
+void
+tag_tracker_init(struct tag_tracker *tracker)
+{
+    memset(tracker, 0, sizeof *tracker);
+}
+
+/* Adds 'add' to '*tags' and records the bits added in 'tracker'. */
+void
+tag_tracker_add(struct tag_tracker *tracker, tag_type *tags, tag_type add)
+{
+    *tags |= add;
+    for (; add; add = zero_rightmost_1bit(add)) {
+        tracker->counts[rightmost_1bit_idx(add)]++;
+    }
+}
+
+/* Removes 'sub' from 'tracker' and unsets any bits in '*tags' that no
+ * remaining tag includes. */
+void
+tag_tracker_subtract(struct tag_tracker *tracker, tag_type *tags, tag_type sub)
+{
+    for (; sub; sub = zero_rightmost_1bit(sub)) {
+        if (!--tracker->counts[rightmost_1bit_idx(sub)]) {
+            *tags &= ~rightmost_1bit(sub);
+        }
+    }
+}