Lucene example source code file (DeleteDocTask.java)

This example Lucene source code file (DeleteDocTask.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

default_doc_delete_step, default_doc_delete_step, deletedoctask, deletedoctask, exception, exception, indexreader, override, override, perftask, string

The Lucene DeleteDocTask.java source code

package org.apache.lucene.benchmark.byTask.tasks;

/**
 * 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.benchmark.byTask.PerfRunData;
import org.apache.lucene.index.IndexReader;

/**
 * Delete a document by docid. If no docid param is supplied, deletes doc with
 * <code>id = last-deleted-doc + doc.delete.step.
 */
public class DeleteDocTask extends PerfTask {

  /**
   * Gap between ids of deleted docs, applies when no docid param is provided.
   */
  public static final int DEFAULT_DOC_DELETE_STEP = 8;
  
  public DeleteDocTask(PerfRunData runData) {
    super(runData);
  }

  private int deleteStep = -1;
  private static int lastDeleted = -1;

  private int docid = -1;
  private boolean byStep = true;
  
  @Override
  public int doLogic() throws Exception {
    IndexReader r = getRunData().getIndexReader();
    r.deleteDocument(docid);
    lastDeleted = docid;
    r.decRef();
    return 1; // one work item done here
  }

  /* (non-Javadoc)
   * @see org.apache.lucene.benchmark.byTask.tasks.PerfTask#setup()
   */
  @Override
  public void setup() throws Exception {
    super.setup();
    if (deleteStep<0) {
      deleteStep = getRunData().getConfig().get("doc.delete.step",DEFAULT_DOC_DELETE_STEP);
    }
    // set the docid to be deleted
    docid = (byStep ? lastDeleted + deleteStep : docid);
  }

  @Override
  protected String getLogMessage(int recsCount) {
    return "deleted " + recsCount + " docs, last deleted: " + lastDeleted;
  }
  
  /**
   * Set the params (docid only)
   * @param params docid to delete, or -1 for deleting by delete gap settings.
   */
  @Override
  public void setParams(String params) {
    super.setParams(params);
    docid = (int) Float.parseFloat(params);
    byStep = (docid < 0);
  }
  
  /* (non-Javadoc)
   * @see org.apache.lucene.benchmark.byTask.tasks.PerfTask#supportsParams()
   */
  @Override
  public boolean supportsParams() {
    return true;
  }

}