FieldFacetAccumulator.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.solr.analytics.accumulator.facet;

import java.io.IOException;

import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.index.NumericDocValues;
import org.apache.lucene.index.SortedDocValues;
import org.apache.lucene.index.SortedSetDocValues;
import org.apache.lucene.util.BytesRef;
import org.apache.solr.analytics.accumulator.FacetingAccumulator;
import org.apache.solr.analytics.accumulator.ValueAccumulator;
import org.apache.solr.analytics.util.AnalyticsParsers.NumericParser;
import org.apache.solr.analytics.util.AnalyticsParsers.Parser;
import org.apache.solr.analytics.util.AnalyticsParsers;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.schema.DateValueFieldType;
import org.apache.solr.schema.SchemaField;
import org.apache.solr.search.SolrIndexSearcher;

/**
 * An Accumulator that manages the faceting for fieldFacets.
 * Collects the field facet values.
 */
public class FieldFacetAccumulator extends ValueAccumulator {
  protected final Parser parser;
  protected final FacetValueAccumulator parent;
  protected final String name;
  protected final SolrIndexSearcher searcher;
  protected final SchemaField schemaField;
  protected final boolean multiValued;
  protected final boolean numField;
  protected final boolean dateField;
  protected SortedSetDocValues setValues;
  protected SortedDocValues sortValues;
  protected NumericDocValues numValues;
  
  public FieldFacetAccumulator(SolrIndexSearcher searcher, FacetValueAccumulator parent, SchemaField schemaField) throws IOException {  
    if( !schemaField.hasDocValues() ){
      throw new IOException("Field '"+schemaField.getName()+"' does not have docValues and therefore cannot be faceted over.");
    }
    this.searcher = searcher;
    this.schemaField = schemaField;
    this.name = schemaField.getName();
    this.multiValued = schemaField.multiValued();
    this.numField = schemaField.getType().getNumberType()!=null;
    this.dateField = schemaField.getType() instanceof DateValueFieldType;
    this.parent = parent;  
    this.parser = AnalyticsParsers.getParser(schemaField.getType().getClass());
  }

  public static FieldFacetAccumulator create(SolrIndexSearcher searcher, FacetValueAccumulator parent, SchemaField facetField) throws IOException{
    return new FieldFacetAccumulator(searcher,parent,facetField);
  }

  /**
   * Move to the next set of documents to add to the field facet.
   */
  @Override
  protected void doSetNextReader(LeafReaderContext context) throws IOException {
    if (multiValued) {
      setValues = context.reader().getSortedSetDocValues(name);
    } else {
      if (numField) {
        numValues = context.reader().getNumericDocValues(name);
      } else {
        sortValues = context.reader().getSortedDocValues(name);
      }
    }
  }

  /**
   * Tell the FacetingAccumulator to collect the doc with the 
   * given fieldFacet and value(s).
   */
  @Override
  public void collect(int doc) throws IOException {
    if (multiValued) {
      boolean exists = false;
      if (setValues!=null) {
        if (doc > setValues.docID()) {
          setValues.advance(doc);
        }
        if (doc == setValues.docID()) {
          int term;
          while ((term = (int)setValues.nextOrd()) != SortedSetDocValues.NO_MORE_ORDS) {
            exists = true;
            final BytesRef value = setValues.lookupOrd(term);
            parent.collectField(doc, name, parser.parse(value) );
          }
        }
      }
      if (!exists) {
        parent.collectField(doc, name, FacetingAccumulator.MISSING_VALUE );
      }
    } else {
      if(numField){
        if(numValues != null) {
          int valuesDocID = numValues.docID();
          if (valuesDocID < doc) {
            valuesDocID = numValues.advance(doc);
          }
          if (valuesDocID == doc) {
            parent.collectField(doc, name, ((NumericParser)parser).parseNum(numValues.longValue()));
          } else {
            parent.collectField(doc, name, FacetingAccumulator.MISSING_VALUE );
          }
        } else {
          parent.collectField(doc, name, FacetingAccumulator.MISSING_VALUE );
        }
      } else {
        if(sortValues != null) {
          if (doc > sortValues.docID()) {
            sortValues.advance(doc);
          }
          if (doc == sortValues.docID()) {
            parent.collectField(doc, name, parser.parse(sortValues.lookupOrd(sortValues.ordValue())) );
          } else {
            parent.collectField(doc, name, FacetingAccumulator.MISSING_VALUE );
          }
        } else {
          parent.collectField(doc, name, FacetingAccumulator.MISSING_VALUE );
        }
      }
    }
  }

  @Override
  public void compute() {}
 
  @Override
  public NamedList<?> export() { return null; }

  @Override
  public boolean needsScores() {
    return true; // TODO: is this true?
  }
}