[ http://issues.apache.org/jira/browse/LUCENE-584?page=comments#action_12431684 ] Yonik Seeley commented on LUCENE-584: -------------------------------------
Thanks Paul, I like the Matcher/Scorer relation. It looks like no Filters currently return a matcher, so the current patch just lays the groundwork, right? When some filters do start to return a matcher, it looks like support for the 1.4 BooleanScorer needs to be removed, or a check done in IndexSearcher.search() to disable skipping on the scorer if it's in use. I wonder what the performance impact is... for a dense search with a dense bitset filter, it looks like quite a bit of overhead is added (two calls in order to get the next doc, use of nextSetBit() instead of get(), checking "exhausted" each time and checking for -1 to set exhausted). I suppose one can always drop back to using a HitCollector for special cases though. > Decouple Filter from BitSet > --------------------------- > > Key: LUCENE-584 > URL: http://issues.apache.org/jira/browse/LUCENE-584 > Project: Lucene - Java > Issue Type: Improvement > Components: Search > Affects Versions: 2.0.1 > Reporter: Peter Schäfer > Priority: Minor > Attachments: BitsMatcher.java, Filter-20060628.patch, > HitCollector-20060628.patch, IndexSearcher-20060628.patch, > MatchCollector.java, Matcher.java, Matcher20060830.patch, > Scorer-20060628.patch, Searchable-20060628.patch, Searcher-20060628.patch, > SortedVIntList.java, TestSortedVIntList.java > > > {code} > package org.apache.lucene.search; > public abstract class Filter implements java.io.Serializable > { > public abstract AbstractBitSet bits(IndexReader reader) throws IOException; > } > public interface AbstractBitSet > { > public boolean get(int index); > } > {code} > It would be useful if the method =Filter.bits()= returned an abstract > interface, instead of =java.util.BitSet=. > Use case: there is a very large index, and, depending on the user's > privileges, only a small portion of the index is actually visible. > Sparsely populated =java.util.BitSet=s are not efficient and waste lots of > memory. It would be desirable to have an alternative BitSet implementation > with smaller memory footprint. > Though it _is_ possibly to derive classes from =java.util.BitSet=, it was > obviously not designed for that purpose. > That's why I propose to use an interface instead. The default implementation > could still delegate to =java.util.BitSet=. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
