content: package org.apache.solr.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 org.apache.lucene.index.IndexReader;
  import org.apache.lucene.search.Collector;
  import org.apache.lucene.search.Scorer;
  import org.apache.lucene.util.OpenBitSet;
  
  import java.io.IOException;
  
  /**
   *
   */
  public class DocSetDelegateCollector extends DocSetCollector {
    final Collector collector;
  
    public DocSetDelegateCollector(int smallSetSize, int maxDoc, Collector collector) {
      super(smallSetSize, maxDoc);
      this.collector = collector;
    }
  
    @Override
    public void collect(int doc) throws IOException {
      collector.collect(doc);
  
      doc += base;
      // optimistically collect the first docs in an array
      // in case the total number will be small enough to represent
      // as a small set like SortedIntDocSet instead...
      // Storing in this array will be quicker to convert
      // than scanning through a potentially huge bit vector.
      // FUTURE: when search methods all start returning docs in order, maybe
      // we could have a ListDocSet() and use the collected array directly.
      if (pos < scratch.length) {
        scratch[pos]=doc;
      } else {
        // this conditional could be removed if BitSet was preallocated, but that
        // would take up more memory, and add more GC time...
        if (bits==null) bits = new OpenBitSet(maxDoc);
        bits.fastSet(doc);
      }
  
      pos++;
    }
  
    @Override
    public DocSet getDocSet() {
      if (pos<=scratch.length) {
        // assumes docs were collected in sorted order!
        return new SortedIntDocSet(scratch, pos);
      } else {
        // set the bits for ids that were collected in the array
        for (int i=0; i<scratch.length; i++) bits.fastSet(scratch[i]);
        return new BitDocSet(bits,pos);
      }
    }
  
    @Override
    public void setScorer(Scorer scorer) throws IOException {
      collector.setScorer(scorer);
    }
  
    @Override
    public void setNextReader(IndexReader indexReader, int docBase) throws IOException {
      collector.setNextReader(indexReader, docBase);
      this.base = docBase;
    }
  }
  