X-Git-Url: https://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb2%2Fhash.c;h=69df151e98e8100593d0a5582b8cfd84c09dac05;hp=51874918c62ef4fb53e5581c252e8ace6301de9a;hb=576802602c19ed3cfda98414ffc9b118c2675931;hpb=c5e3f07a30056cb7c3c380bf690f80815ca4b6b1

diff --git a/ccan/tdb2/hash.c b/ccan/tdb2/hash.c
index 51874918..69df151e 100644
--- a/ccan/tdb2/hash.c
+++ b/ccan/tdb2/hash.c
@@ -42,17 +42,19 @@ uint64_t tdb_hash(struct tdb_context *tdb, const void *ptr, size_t len)
 
 uint64_t hash_record(struct tdb_context *tdb, tdb_off_t off)
 {
-	struct tdb_used_record pad, *r;
+	const struct tdb_used_record *r;
 	const void *key;
 	uint64_t klen, hash;
 
-	r = tdb_get(tdb, off, &pad, sizeof(pad));
+	r = tdb_access_read(tdb, off, sizeof(*r), true);
 	if (!r)
 		/* FIXME */
 		return 0;
 
 	klen = rec_key_length(r);
-	key = tdb_access_read(tdb, off + sizeof(pad), klen, false);
+	tdb_access_release(tdb, r);
+
+	key = tdb_access_read(tdb, off + sizeof(*r), klen, false);
 	if (!key)
 		return 0;
 
@@ -87,10 +89,6 @@ static bool match(struct tdb_context *tdb,
 	const unsigned char *rkey;
 	tdb_off_t off;
 
-	/* FIXME: Handle hash value truncated. */
-	if (bits(val, TDB_OFF_HASH_TRUNCATED_BIT, 1))
-		abort();
-
 	/* Desired bucket must match. */
 	if (h->home_bucket != (val & TDB_OFF_HASH_GROUP_MASK))
 		return false;
@@ -123,10 +121,9 @@ static tdb_off_t hbucket_off(tdb_off_t group_start, unsigned bucket)
 		+ (bucket % (1 << TDB_HASH_GROUP_BITS)) * sizeof(tdb_off_t);
 }
 
-/* Truncated hashes can't be all 1: that's how we spot a sub-hash */
 bool is_subhash(tdb_off_t val)
 {
-	return val >> (64-TDB_OFF_UPPER_STEAL) == (1<<TDB_OFF_UPPER_STEAL) - 1;
+	return (val >> TDB_OFF_UPPER_STEAL_SUBHASH_BIT) & 1;
 }
 
 /* FIXME: Guess the depth, don't over-lock! */
@@ -239,8 +236,8 @@ fail:
 /* I wrote a simple test, expanding a hash to 2GB, for the following
  * cases:
  * 1) Expanding all the buckets at once,
- * 2) Expanding the most-populated bucket,
- * 3) Expanding the bucket we wanted to place the new entry ito.
+ * 2) Expanding the bucket we wanted to place the new entry into.
+ * 3) Expanding the most-populated bucket,
  *
  * I measured the worst/average/best density during this process.
  * 1) 3%/16%/30%
@@ -329,7 +326,6 @@ static int add_to_subhash(struct tdb_context *tdb, tdb_off_t subhash,
 	if (hash_used + TDB_SUBLEVEL_HASH_BITS > 64)
 		abort();
 
-	/* FIXME: Do truncated hash bits if we can! */
 	h.h = hash_record(tdb, off);
 	gnum = use_bits(&h, TDB_SUBLEVEL_HASH_BITS-TDB_HASH_GROUP_BITS);
 	h.group_start = subhash	+ sizeof(struct tdb_used_record)
@@ -358,6 +354,7 @@ static int expand_group(struct tdb_context *tdb, struct hash_info *h)
 	if (subhash == TDB_OFF_ERR)
 		return -1;
 
+	add_stat(tdb, alloc_subhash, 1);
 	if (zero_out(tdb, subhash + sizeof(struct tdb_used_record),
 		     sizeof(tdb_off_t) << TDB_SUBLEVEL_HASH_BITS) == -1)
 		return -1;
@@ -377,7 +374,7 @@ static int expand_group(struct tdb_context *tdb, struct hash_info *h)
 	/* assert(num_vals); */
 
 	/* Overwrite expanded bucket with subhash pointer. */
-	h->group[bucket] = subhash | ~((1ULL << (64 - TDB_OFF_UPPER_STEAL))-1);
+	h->group[bucket] = subhash | (1ULL << TDB_OFF_UPPER_STEAL_SUBHASH_BIT);
 
 	/* Put values back. */
 	for (i = 0; i < num_vals; i++) {