X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Fhtable%2Fhtable.c;h=b7e65d11966acc96be83dffbb25a273fec153145;hp=f3e529211d5b2456bad5165d3baa848de4314d3d;hb=c321a1d02755a77ae790d6e8976b2ff15edba89d;hpb=0c3590dc33d644f73bb8587db454c491830aaf26;ds=sidebyside

diff --git a/ccan/htable/htable.c b/ccan/htable/htable.c
index f3e52921..b7e65d11 100644
--- a/ccan/htable/htable.c
+++ b/ccan/htable/htable.c
@@ -45,18 +45,10 @@ static inline uintptr_t get_hash_ptr_bits(const struct htable *ht,
 void htable_init(struct htable *ht,
 		 size_t (*rehash)(const void *elem, void *priv), void *priv)
 {
-	ht->bits = 0;
+	struct htable empty = HTABLE_INITIALIZER(empty, NULL, NULL);
+	*ht = empty;
 	ht->rehash = rehash;
 	ht->priv = priv;
-	ht->elems = 0;
-	ht->deleted = 0;
-	ht->max = 0;
-	ht->max_with_deleted = 0;
-	/* This guarantees we enter update_common first add. */
-	ht->common_mask = -1;
-	ht->common_bits = 0;
-	ht->perfect_bit = 0;
-	/* Dummy table until first insert. */
 	ht->table = &ht->perfect_bit;
 }
 
@@ -205,8 +197,17 @@ static COLD void update_common(struct htable *ht, const void *p)
 	uintptr_t maskdiff, bitsdiff;
 
 	if (ht->elems == 0) {
-		ht->common_mask = -1;
-		ht->common_bits = (uintptr_t)p;
+		/* Always reveal one bit of the pointer in the bucket,
+		 * so it's not zero or HTABLE_DELETED (1), even if
+		 * hash happens to be 0.  Assumes (void *)1 is not a
+		 * valid pointer. */
+		for (i = sizeof(uintptr_t)*CHAR_BIT - 1; i > 0; i--) {
+			if ((uintptr_t)p & ((uintptr_t)1 << i))
+				break;
+		}
+
+		ht->common_mask = ~((uintptr_t)1 << i);
+		ht->common_bits = ((uintptr_t)p & ht->common_mask);
 		ht->perfect_bit = 1;
 		return;
 	}