UIDFilter.java

package proj.zoie.api;

/**
 * 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 org.apache.lucene.index.AtomicReaderContext;
import org.apache.lucene.index.SegmentReader;
import org.apache.lucene.search.DocIdSet;
import org.apache.lucene.search.Filter;
import org.apache.lucene.util.Bits;

/**
 * Filter implementation based on a list of uids
 */
public class UIDFilter extends Filter {
  private final long[] _filteredIDs;
  private final ZoieSegmentReader<?>[] _subZoieReaders;

  public UIDFilter(long[] filteredIDs, ZoieMultiReader<?> reader) {
    _filteredIDs = filteredIDs;
    _subZoieReaders = reader.getSubReaders();
  }

  @Override
  public DocIdSet getDocIdSet(AtomicReaderContext ctx, Bits acceptDocs) throws IOException {
    SegmentReader reader = (SegmentReader) (ctx.reader());
    int idx = -1;
    for (int i = 0; i < _subZoieReaders.length; ++i) {
      if (_subZoieReaders[i].getSegmentName().equals(reader.getSegmentName())) {
        idx = i;
        break;
      }
    }
    if (idx == -1) {
      throw new IOException("Can't find sub-reader");
    }
    return new UIDDocIdSet(_filteredIDs, _subZoieReaders[idx].getDocIDMapper());
  }
}