Contrived FieldCache Load Test: Lucene 2.4 VS Lucene 2.9

转载：http://www.lucidimagination.com/blog/2009/09/22/contrived-fieldcache-load-test-lucene-2-4-vs-lucene-2-9/

public class ContrivedFCTest extends TestCase {
  public void testLoadTime() throws Exception {
    Directory dir = FSDirectory.getDirectory(System.getProperty("java.io.tmpdir") + File.separator + "test");
    IndexWriter writer = new IndexWriter (dir, new SimpleAnalyzer(), true, IndexWriter.MaxFieldLength.LIMITED);
    writer.setMergeFactor(37);
    writer.setUseCompoundFile(false);
    for(int i = 0; i < 5000000; i++) {
      Document doc = new Document();
      doc.add (new Field ("field",  "String" + i, Field.Store.NO, Field.Index.NOT_ANALYZED));
      writer.addDocument(doc);
    }
    writer.close();
 
    IndexReader reader = IndexReader.open(dir);
    long start = System.currentTimeMillis();
    FieldCache.DEFAULT.getStrings(reader, "field");
    long end = System.currentTimeMillis();
    System.out.println("load time:" + (end - start)/1000.0f + "s");
  }
}

The results?

Lucene 2.4: 150.726s
Lucene 2.9: 9.695