/*
* 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.test;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.Random;
import org.apache.accumulo.core.client.ConditionalWriter;
import org.apache.accumulo.core.data.ConditionalMutation;
/**
* A writer that will sometimes return unknown. When it returns unknown the condition may or may not have been written.
*/
public class FaultyConditionalWriter implements ConditionalWriter {
private ConditionalWriter cw;
private double up;
private Random rand;
private double wp;
public FaultyConditionalWriter(ConditionalWriter cw, double unknownProbability, double writeProbability) {
this.cw = cw;
this.up = unknownProbability;
this.wp = writeProbability;
this.rand = new Random();
}
public Iterator<Result> write(Iterator<ConditionalMutation> mutations) {
ArrayList<Result> resultList = new ArrayList<Result>();
ArrayList<ConditionalMutation> writes = new ArrayList<ConditionalMutation>();
while (mutations.hasNext()) {
ConditionalMutation cm = mutations.next();
if (rand.nextDouble() <= up && rand.nextDouble() > wp)
resultList.add(new Result(Status.UNKNOWN, cm, null));
else
writes.add(cm);
}
if (writes.size() > 0) {
Iterator<Result> results = cw.write(writes.iterator());
while (results.hasNext()) {
Result result = results.next();
if (rand.nextDouble() <= up && rand.nextDouble() <= wp)
result = new Result(Status.UNKNOWN, result.getMutation(), result.getTabletServer());
resultList.add(result);
}
}
return resultList.iterator();
}
public Result write(ConditionalMutation mutation) {
return write(Collections.singleton(mutation).iterator()).next();
}
@Override
public void close() {
cw.close();
}
}