shubhamvishu commented on code in PR #12868:
URL: https://github.com/apache/lucene/pull/12868#discussion_r1414130332
##########
lucene/codecs/src/java/org/apache/lucene/codecs/bloom/FuzzySet.java:
##########
@@ -150,9 +150,10 @@ private FuzzySet(FixedBitSet filter, int bloomSize, int
hashCount) {
* @return NO or MAYBE
*/
public ContainsResult contains(BytesRef value) {
- long hash = hashFunction.hash(value);
- int msb = (int) (hash >>> Integer.SIZE);
- int lsb = (int) hash;
+ long[] hash = hashFunction.hash128(value);
+
+ int msb = ((int) hash[0] >>> Integer.SIZE) >>> 1 + ((int) hash[1] >>>
Integer.SIZE) >>> 1;
+ int lsb = ((int) hash[0]) >>> 1 + ((int) hash[1]) >>> 1;
Review Comment:
I think operator precedence won't let this expression to do exactly what I
initially intended to but we see better performance with this actually. We
should change it to below(and maybe check the results again?):
```java
int msb = (int) (hash[0] >>> (Integer.SIZE + 1)) + (int) (hash[1] >>>
(Integer.SIZE + 1));
int lsb = ((int) hash[0] >>> 1) + ((int) hash[1] >>> 1);
```
UPDATE : Changing to above expression I see a performance regression of
**2.6%** so I think its fine to keep it as is(?) or is there anything I might
me missing.
##########
lucene/codecs/src/java/org/apache/lucene/codecs/bloom/FuzzySet.java:
##########
@@ -150,9 +150,10 @@ private FuzzySet(FixedBitSet filter, int bloomSize, int
hashCount) {
* @return NO or MAYBE
*/
public ContainsResult contains(BytesRef value) {
- long hash = hashFunction.hash(value);
- int msb = (int) (hash >>> Integer.SIZE);
- int lsb = (int) hash;
+ long[] hash = hashFunction.hash128(value);
+
+ int msb = ((int) hash[0] >>> Integer.SIZE) >>> 1 + ((int) hash[1] >>>
Integer.SIZE) >>> 1;
+ int lsb = ((int) hash[0]) >>> 1 + ((int) hash[1]) >>> 1;
Review Comment:
I think operator precedence won't let this expression to do exactly what I
initially intended to but we see better performance with this actually. We
should change it to below(and maybe check the results again?):
```java
int msb = (int) (hash[0] >>> (Integer.SIZE + 1)) + (int) (hash[1] >>>
(Integer.SIZE + 1));
int lsb = ((int) hash[0] >>> 1) + ((int) hash[1] >>> 1);
```
**UPDATE :** Changing to above expression I see a performance regression of
**2.6%** so I think its fine to keep it as is(?) or is there anything I might
me missing.
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