[hibernate-issues] [Hibernate-JIRA] Commented: (HSEARCH-610) AndDocIdSet makeDocIdSetOnAgreedBits() returns wrong values

[ http://opensource.atlassian.com/projects/hibernate/browse/HSEARCH-610?pag... ] Hardy Ferentschik commented on HSEARCH-610: ------------------------------------------- The problem is that the {{DocIdSetIterator}} returned by {{SortedVIntList}} behaves differently when {{advance(int target)}} compared to the iterators returned by {{DocIdBitSet}} and {{OpenBitSet}}. Lets take the example from test test. Assume the following doc id are in the set 0, 5, 6 and 10. We get the {{DocIdSetIterator}} from the {{DocIdBitSet}} and we call {{next()}} until we point to the third element ({{iterator.docID() == 6}}. Now we call {{iterator.advance(6)}}. The algorithm in {{AndDocIdSet}} assumes that the advance call will return 6, basically not moving to another element. This is also how {{DocIdBitSet}} and {{OpenBitSet}} behave. {{DocIdSetIterator}}, however, returns 10. The question is who is right. The {{DocIdSetIterator.advance}} javadoc says: {quote} Advances to the first beyond the current whose document number is greater than or equal to _target_ {quote} It also shows some pseudo code: {code} int advance(int target) { int doc; while ((doc = nextDoc()) < target) { } return doc; } {code} Reading this documentation I would think {{SortedVIntList}} behaves correctly, but I think {{OpenBitSet}} is the more commonly used. I am surprised that no one has noticed this before. On our {{AndDocIdSet}} side we can actually cater for this problem by comparing {{iterator.docID() == targetPosition}} before we call {{advance}}. If they match we don't have to call advance at all, because the iterator is already at the right position. Need to follow up with the Lucene guys as well. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://opensource.atlassian.com/projects/hibernate/secure/Administrators.... - For more information on JIRA, see: http://www.atlassian.com/software/jira