Lucene example source code file (TestTopDocsMerge.java)

This example Lucene source code file (TestTopDocsMerge.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Lucene tags/keywords

fielddoc, indexreader, indexsearcher, io, scoredoc, shardsearcher, shardsearcher, sortfield, sortfield, string, topdocs, topdocs, topfielddocs, util, verbose, verbose

The Lucene TestTopDocsMerge.java source code

package org.apache.lucene.search;

/**
 * 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.
 */

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.NumericField;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.RandomIndexWriter;
import org.apache.lucene.index.Term;
import org.apache.lucene.store.Directory;
import org.apache.lucene.util.LuceneTestCase;
import org.apache.lucene.util.ReaderUtil;
import org.apache.lucene.util._TestUtil;

public class TestTopDocsMerge extends LuceneTestCase {

  private static class ShardSearcher {
    private final IndexSearcher subSearcher;

    public ShardSearcher(IndexReader subReader) {
      this.subSearcher = new IndexSearcher(subReader);
    }

    public void search(Weight weight, Collector collector) throws IOException {
      subSearcher.search(weight, null, collector);
    }

    public TopDocs search(Weight weight, int topN) throws IOException {
      return subSearcher.search(weight, null, topN);
    }

    @Override
    public String toString() {
      return "ShardSearcher(" + subSearcher + ")";
    }
  }

  public void testSort() throws Exception {

    IndexReader reader = null;
    Directory dir = null;

    final int numDocs = atLeast(1000);
    //final int numDocs = atLeast(50);

    final String[] tokens = new String[] {"a", "b", "c", "d", "e"};

    if (VERBOSE) {
      System.out.println("TEST: make index");
    }

    {
      dir = newDirectory();
      final RandomIndexWriter w = new RandomIndexWriter(random, dir);
      // w.setDoRandomOptimize(false);

      // w.w.getConfig().setMaxBufferedDocs(atLeast(100));

      final String[] content = new String[atLeast(20)];

      for(int contentIDX=0;contentIDX<content.length;contentIDX++) {
        final StringBuilder sb = new StringBuilder();
        final int numTokens = _TestUtil.nextInt(random, 1, 10);
        for(int tokenIDX=0;tokenIDX<numTokens;tokenIDX++) {
          sb.append(tokens[random.nextInt(tokens.length)]).append(' ');
        }
        content[contentIDX] = sb.toString();
      }

      for(int docIDX=0;docIDX<numDocs;docIDX++) {
        final Document doc = new Document();
        doc.add(newField("string", _TestUtil.randomRealisticUnicodeString(random), Field.Index.NOT_ANALYZED));
        doc.add(newField("text", content[random.nextInt(content.length)], Field.Index.ANALYZED));
        doc.add(new NumericField("float").setFloatValue(random.nextFloat()));
        final int intValue;
        if (random.nextInt(100) == 17) {
          intValue = Integer.MIN_VALUE;
        } else if (random.nextInt(100) == 17) {
          intValue = Integer.MAX_VALUE;
        } else {
          intValue = random.nextInt();
        }
        doc.add(new NumericField("int").setIntValue(intValue));
        if (VERBOSE) {
          System.out.println("  doc=" + doc);
        }
        w.addDocument(doc);
      }

      reader = w.getReader();
      w.close();
    }

    // NOTE: sometimes reader has just one segment, which is
    // important to test
    final IndexSearcher searcher = newSearcher(reader);
    IndexReader[] subReaders = searcher.getIndexReader().getSequentialSubReaders();
    if (subReaders == null) {
      subReaders = new IndexReader[] {searcher.getIndexReader()};
    }
    final ShardSearcher[] subSearchers = new ShardSearcher[subReaders.length];

    for(int searcherIDX=0;searcherIDX<subSearchers.length;searcherIDX++) { 
      subSearchers[searcherIDX] = new ShardSearcher(subReaders[searcherIDX]);
    }

    final List<SortField> sortFields = new ArrayList();
    sortFields.add(new SortField("string", SortField.STRING, true));
    sortFields.add(new SortField("string", SortField.STRING, false));
    sortFields.add(new SortField("int", SortField.INT, true));
    sortFields.add(new SortField("int", SortField.INT, false));
    sortFields.add(new SortField("float", SortField.FLOAT, true));
    sortFields.add(new SortField("float", SortField.FLOAT, false));
    sortFields.add(new SortField(null, SortField.SCORE, true));
    sortFields.add(new SortField(null, SortField.SCORE, false));
    sortFields.add(new SortField(null, SortField.DOC, true));
    sortFields.add(new SortField(null, SortField.DOC, false));

    final int[] docStarts = new int[subSearchers.length];
    int docBase = 0;
    for(int subIDX=0;subIDX<docStarts.length;subIDX++) {
      docStarts[subIDX] = docBase;
      docBase += subReaders[subIDX].maxDoc();
      if (VERBOSE) {
        System.out.println("docStarts[" + subIDX + "]=" + docStarts[subIDX]);
      }
    }

    for(int iter=0;iter<1000*RANDOM_MULTIPLIER;iter++) {

      // TODO: custom FieldComp...
      final Query query = new TermQuery(new Term("text", tokens[random.nextInt(tokens.length)]));

      final Sort sort;
      if (random.nextInt(10) == 4) {
        // Sort by score
        sort = null;
      } else {
        final SortField[] randomSortFields = new SortField[_TestUtil.nextInt(random, 1, 3)];
        for(int sortIDX=0;sortIDX<randomSortFields.length;sortIDX++) {
          randomSortFields[sortIDX] = sortFields.get(random.nextInt(sortFields.size()));
        }
        sort = new Sort(randomSortFields);
      }

      final int numHits = _TestUtil.nextInt(random, 1, numDocs+5);
      //final int numHits = 5;
      
      if (VERBOSE) {
        System.out.println("TEST: search query=" + query + " sort=" + sort + " numHits=" + numHits);
      }

      // First search on whole index:
      final TopDocs topHits;
      if (sort == null) {
        topHits = searcher.search(query, numHits);
      } else {
        final TopFieldCollector c = TopFieldCollector.create(sort, numHits, true, true, true, random.nextBoolean());
        searcher.search(query, c);
        topHits = c.topDocs(0, numHits);
      }

      if (VERBOSE) {
        System.out.println("  top search: " + topHits.totalHits + " totalHits; hits=" + (topHits.scoreDocs == null ? "null" : topHits.scoreDocs.length));
        if (topHits.scoreDocs != null) {
          for(int hitIDX=0;hitIDX<topHits.scoreDocs.length;hitIDX++) {
            final ScoreDoc sd = topHits.scoreDocs[hitIDX];
            System.out.println("    doc=" + sd.doc + " score=" + sd.score);
          }
        }
      }

      // ... then all shards:
      final Weight w = searcher.createNormalizedWeight(query);

      final TopDocs[] shardHits = new TopDocs[subSearchers.length];
      for(int shardIDX=0;shardIDX<subSearchers.length;shardIDX++) {
        final TopDocs subHits;
        final ShardSearcher subSearcher = subSearchers[shardIDX];
        if (sort == null) {
          subHits = subSearcher.search(w, numHits);
        } else {
          final TopFieldCollector c = TopFieldCollector.create(sort, numHits, true, true, true, random.nextBoolean());
          subSearcher.search(w, c);
          subHits = c.topDocs(0, numHits);
        }
        rebaseDocIDs(docStarts[shardIDX], subHits);

        shardHits[shardIDX] = subHits;
        if (VERBOSE) {
          System.out.println("  shard=" + shardIDX + " " + subHits.totalHits + " totalHits hits=" + (subHits.scoreDocs == null ? "null" : subHits.scoreDocs.length));
          if (subHits.scoreDocs != null) {
            for(ScoreDoc sd : subHits.scoreDocs) {
              System.out.println("    doc=" + sd.doc + " score=" + sd.score);
            }
          }
        }
      }

      // Merge:
      final TopDocs mergedHits = TopDocs.merge(sort, numHits, shardHits);

      if (VERBOSE) {
        System.out.println("  mergedHits: " + mergedHits.totalHits + " totalHits; hits=" + (mergedHits.scoreDocs == null ? "null" : mergedHits.scoreDocs.length));
        if (mergedHits.scoreDocs != null) {
          for(int hitIDX=0;hitIDX<mergedHits.scoreDocs.length;hitIDX++) {
            final ScoreDoc sd = mergedHits.scoreDocs[hitIDX];
            System.out.println("    doc=" + sd.doc + " score=" + sd.score);
          }
        }
      }
      if (mergedHits.scoreDocs != null) {
        // Make sure the returned shards are correct:
        for(int hitIDX=0;hitIDX<mergedHits.scoreDocs.length;hitIDX++) {
          final ScoreDoc sd = mergedHits.scoreDocs[hitIDX];
          assertEquals("doc=" + sd.doc + " wrong shard",
                       ReaderUtil.subIndex(sd.doc, docStarts),
                       sd.shardIndex);
        }
      }

      _TestUtil.assertEquals(topHits, mergedHits);
    }
    searcher.close();
    reader.close();
    dir.close();
  }

  private void rebaseDocIDs(int docBase, TopDocs hits) {
    List<Integer> docFieldLocs = new ArrayList();
    if (hits instanceof TopFieldDocs) {
      TopFieldDocs fieldHits = (TopFieldDocs) hits;
      for(int fieldIDX=0;fieldIDX<fieldHits.fields.length;fieldIDX++) {
        if (fieldHits.fields[fieldIDX].getType() == SortField.DOC) {
          docFieldLocs.add(fieldIDX);
        }
      }
    }

    for(int hitIDX=0;hitIDX<hits.scoreDocs.length;hitIDX++) {
      final ScoreDoc sd = hits.scoreDocs[hitIDX];
      sd.doc += docBase;
      if (sd instanceof FieldDoc) {
        final FieldDoc fd = (FieldDoc) sd;
        if (fd.fields != null) {
          for(int idx : docFieldLocs) {
            fd.fields[idx] = Integer.valueOf(((Integer) fd.fields[idx]).intValue() + docBase);
          }
        }
      }
    }
  }
}