Here's a diff to ConstantScoreQuery that optionally folds in norms (minus explain() functionality right now). Should it be added, or do the differences warrant a new Query class, or if kept together, should ConstantScoreQuery be renamed since it's not quite so constant?
-Yonik Now hiring -- http://forms.cnet.com/slink?231706 --- src/java/org/apache/lucene/search/ConstantScoreQuery.java (revision 344312) +++ src/java/org/apache/lucene/search/ConstantScoreQuery.java (working copy) @@ -23,16 +23,29 @@ /** * A query that wraps a filter and simply returns a constant score equal to the - * query boost for every document in the filter. + * query boost for every document in the filter. Field boosts and field length + * normalization factors may be enabled by providing a field to use. * * @author yonik * @version $Id$ */ public class ConstantScoreQuery extends Query { - protected final Filter filter; + protected Filter filter; + protected String field; - public ConstantScoreQuery(Filter filter) { + /** + * @param filter the set of documents to produce a score for + * @param field If non-null, this field's norms are + * multiplied into the score, effectively enabling index time field boosts + * and field length normalization. + */ + public ConstantScoreQuery(Filter filter, String field) { this.filter=filter; + this.field = field; + } + + public ConstantScoreQuery(Filter filter) { + this(filter, null); } public Query rewrite(IndexReader reader) throws IOException { @@ -67,7 +80,9 @@ } public Scorer scorer(IndexReader reader) throws IOException { - return new ConstantScorer(getSimilarity(searcher), reader, this); + return new ConstantScorer(getSimilarity(searcher), reader, this, + (field!=null && reader.hasNorms(field)) ? reader.norms(field) : null + ); } public Explanation explain(IndexReader reader, int doc) throws IOException { @@ -95,12 +110,16 @@ protected class ConstantScorer extends Scorer { final BitSet bits; final float theScore; + final byte[] norms; + final float[] normDecoder = Similarity.getNormDecoder(); + int doc=-1; - public ConstantScorer(Similarity similarity, IndexReader reader, Weight w) throws IOException { + public ConstantScorer(Similarity similarity, IndexReader reader, Weight w, byte[] norms) throws IOException { super(similarity); theScore = w.getValue(); bits = filter.bits(reader); + this.norms = norms; } public boolean next() throws IOException { @@ -113,7 +132,7 @@ } public float score() throws IOException { - return theScore; + return norms==null ? theScore : theScore*normDecoder[norms[doc]&0xFF]; } public boolean skipTo(int target) throws IOException { --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
