the-algorithm/src/java/com/twitter/search/earlybird/search/relevance/scoring/DefaultScoringFunction.java

package com.twitter.search.earlybird.search.relevance.scoring;

import org.apache.lucene.search.Explanation;

import com.twitter.search.common.schema.base.ImmutableSchemaInterface;
import com.twitter.search.earlybird.thrift.ThriftSearchResultsRelevanceStats;

/*
 * A sample scorer, doesn't really do anything, returns the same score for every document.
 */
public class DefaultScoringFunction extends ScoringFunction {
  private float score;

  public DefaultScoringFunction(ImmutableSchemaInterface schema) {
    super(schema);
  }

  @Override
  protected float score(float luceneQueryScore) {
    score = luceneQueryScore;
    return luceneQueryScore;
  }

  @Override
  protected Explanation doExplain(float luceneScore) {
    // just an example - this scoring function will go away soon
    return Explanation.match(luceneScore, "luceneScore=" + luceneScore);
  }

  @Override
  public void updateRelevanceStats(ThriftSearchResultsRelevanceStats relevanceStats) {
    relevanceStats.setNumScored(relevanceStats.getNumScored() + 1);
    if (score == ScoringFunction.SKIP_HIT) {
      relevanceStats.setNumSkipped(relevanceStats.getNumSkipped() + 1);
    }
  }
}