core/src/main/java/org/apache/accumulo/testing/core/randomwalk/shard/DeleteWord.java

/*
 * 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.
 */
package org.apache.accumulo.testing.core.randomwalk.shard;

import java.util.ArrayList;
import java.util.Map.Entry;
import java.util.Properties;
import java.util.Random;

import org.apache.accumulo.core.client.BatchScanner;
import org.apache.accumulo.core.client.BatchWriter;
import org.apache.accumulo.core.client.Scanner;
import org.apache.accumulo.core.data.Key;
import org.apache.accumulo.core.data.Mutation;
import org.apache.accumulo.core.data.Range;
import org.apache.accumulo.core.data.Value;
import org.apache.accumulo.core.security.Authorizations;
import org.apache.accumulo.testing.core.randomwalk.RandWalkEnv;
import org.apache.accumulo.testing.core.randomwalk.State;
import org.apache.accumulo.testing.core.randomwalk.Test;
import org.apache.hadoop.io.Text;

/**
 * Delete all documents containing a particular word.
 *
 */

public class DeleteWord extends Test {

  @Override
  public void visit(State state, RandWalkEnv env, Properties props) throws Exception {
    String indexTableName = (String) state.get("indexTableName");
    String docTableName = (String) state.get("docTableName");
    int numPartitions = (Integer) state.get("numPartitions");
    Random rand = (Random) state.get("rand");

    String wordToDelete = Insert.generateRandomWord(rand);

    // use index to find all documents containing word
    Scanner scanner = env.getAccumuloClient().createScanner(indexTableName, Authorizations.EMPTY);
    scanner.fetchColumnFamily(new Text(wordToDelete));

    ArrayList<Range> documentsToDelete = new ArrayList<>();

    for (Entry<Key,Value> entry : scanner)
      documentsToDelete.add(new Range(entry.getKey().getColumnQualifier()));

    if (documentsToDelete.size() > 0) {
      // use a batch scanner to fetch all documents
      BatchScanner bscanner = env.getAccumuloClient().createBatchScanner(docTableName, Authorizations.EMPTY, 8);
      bscanner.setRanges(documentsToDelete);

      BatchWriter ibw = env.getMultiTableBatchWriter().getBatchWriter(indexTableName);
      BatchWriter dbw = env.getMultiTableBatchWriter().getBatchWriter(docTableName);

      int count = 0;

      for (Entry<Key,Value> entry : bscanner) {
        String docID = entry.getKey().getRow().toString();
        String doc = entry.getValue().toString();

        Insert.unindexDocument(ibw, doc, docID, numPartitions);

        Mutation m = new Mutation(docID);
        m.putDelete("doc", "");

        dbw.addMutation(m);
        count++;
      }

      bscanner.close();

      env.getMultiTableBatchWriter().flush();

      if (count != documentsToDelete.size()) {
        throw new Exception("Batch scanner did not return expected number of docs " + count + " " + documentsToDelete.size());
      }
    }

    log.debug("Deleted " + documentsToDelete.size() + " documents containing " + wordToDelete);
  }

}