tag: Reintroduce tag library.

[sliver-openvswitch.git] / lib / tag.c

diff --git a/lib/tag.c b/lib/tag.c
index f064d17..b45bcd5 100644 (file)
--- a/lib/tag.c
+++ b/lib/tag.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010, 2011 Nicira, Inc.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2013 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,9 +17,6 @@
 #include <config.h>
 #include "tag.h"
 #include <limits.h>
-#include "random.h"
-#include "type-props.h"
-#include "util.h"
 
 #define N_TAG_BITS (CHAR_BIT * sizeof(tag_type))
 BUILD_ASSERT_DECL(IS_POW2(N_TAG_BITS));
@@ -27,19 +24,6 @@ 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);
 
-/* Returns a randomly selected tag. */
-tag_type
-tag_create_random(void)
-{
-    int x, y;
-    do {
-        uint16_t r = random_uint16();
-        x = r & (N_TAG_BITS - 1);
-        y = r >> (16 - LOG2_N_TAG_BITS);
-    } while (x == y);
-    return (1u << x) | (1u << y);
-}
-
 /* Returns a tag deterministically generated from 'seed'.
  *
  * 'seed' should have data in all of its bits; if it has data only in its
@@ -53,65 +37,3 @@ tag_create_deterministic(uint32_t seed)
     y += y >= x;
     return (1u << x) | (1u << y);
 }
-
-/* Initializes 'set' as an empty tag set. */
-void
-tag_set_init(struct tag_set *set)
-{
-    memset(set, 0, sizeof *set);
-}
-
-static bool
-tag_is_worth_adding(const struct tag_set *set, tag_type tag)
-{
-    if (!tag) {
-        /* Nothing to add. */
-        return false;
-    } else if ((set->total & tag) != tag) {
-        /* 'set' doesn't have all the bits in 'tag', so we need to add it. */
-        return true;
-    } else {
-        /* We can drop it if some member of 'set' already includes all of the
-         * 1-bits in 'tag'.  (tag_set_intersects() does a different test:
-         * whether some member of 'set' has at least two 1-bit in common with
-         * 'tag'.) */
-        int i;
-
-        for (i = 0; i < TAG_SET_SIZE; i++) {
-            if ((set->tags[i] & tag) == tag) {
-                return false;
-            }
-        }
-        return true;
-    }
-}
-
-/* Adds 'tag' to 'set'. */
-void
-tag_set_add(struct tag_set *set, tag_type tag)
-{
-    if (tag_is_worth_adding(set, tag)) {
-        /* XXX We could do better by finding the set member to which we would
-         * add the fewest number of 1-bits.  This would reduce the amount of
-         * ambiguity, since e.g. three 1-bits match 3 * 2 / 2 = 3 unique tags
-         * whereas four 1-bits match 4 * 3 / 2 = 6 unique tags. */
-        tag_type *t = &set->tags[set->n++ % TAG_SET_SIZE];
-        *t |= tag;
-        if (*t == TYPE_MAXIMUM(tag_type)) {
-            set->tags[0] = *t;
-        }
-
-        set->total |= tag;
-    }
-}
-
-/* Adds all the tags in 'other' to 'set'. */
-void
-tag_set_union(struct tag_set *set, const struct tag_set *other)
-{
-    size_t i;
-
-    for (i = 0; i < TAG_SET_SIZE; i++) {
-        tag_set_add(set, other->tags[i]);
-    }
-}