NoopReaderCache.java

package proj.zoie.impl.indexing;

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

import org.apache.log4j.Logger;
import org.apache.lucene.index.IndexReader;

import proj.zoie.api.IndexReaderFactory;
import proj.zoie.api.ZoieException;
import proj.zoie.api.ZoieMultiReader;

public class NoopReaderCache<R extends IndexReader> extends AbstractReaderCache<R> {
  private static final Logger log = Logger.getLogger(NoopReaderCache.class);
  private volatile boolean alreadyShutdown = false;
  private final IndexReaderFactory<R> _readerfactory;

  public NoopReaderCache(IndexReaderFactory<R> readerfactory) {
    _readerfactory = readerfactory;
  }

  @Override
  public List<ZoieMultiReader<R>> getIndexReaders() {
    if (!alreadyShutdown) {
      try {
        return _readerfactory.getIndexReaders();
      } catch (IOException e) {
        log.error("getIndexReaders", e);
      }
    }
    return new ArrayList<ZoieMultiReader<R>>(0);
  }

  @Override
  public void returnIndexReaders(List<ZoieMultiReader<R>> readers) {
    _readerfactory.returnIndexReaders(readers);
  }

  @Override
  public void refreshCache(long timeout) throws ZoieException {
  }

  @Override
  public void shutdown() {
    alreadyShutdown = true;
  }

  @Override
  public void start() {
  }

  @Override
  public long getFreshness() {
    return 0;
  }

  @Override
  public void setFreshness(long freshness) {
  }

  public static ReaderCacheFactory FACTORY = new ReaderCacheFactory() {

    @Override
    public <R extends IndexReader> AbstractReaderCache<R> newInstance(
        IndexReaderFactory<R> readerfactory) {
      return new NoopReaderCache<R>(readerfactory);
    }
  };
}