| /* |
| * 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.iteratortest.testcases; |
| |
| import java.io.IOException; |
| import java.security.SecureRandom; |
| import java.util.Collection; |
| import java.util.Random; |
| import java.util.TreeMap; |
| |
| import org.apache.accumulo.core.data.ByteSequence; |
| import org.apache.accumulo.core.data.Key; |
| import org.apache.accumulo.core.data.Range; |
| import org.apache.accumulo.core.data.Value; |
| import org.apache.accumulo.core.iterators.SortedKeyValueIterator; |
| import org.apache.accumulo.iteratortest.IteratorTestInput; |
| import org.apache.accumulo.iteratortest.IteratorTestOutput; |
| import org.apache.accumulo.iteratortest.IteratorTestUtil; |
| import org.apache.accumulo.iteratortest.environments.SimpleIteratorEnvironment; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Test case that verifies that an iterator can use the generated instance from {@code deepCopy}. |
| */ |
| public class ReSeekTestCase extends OutputVerifyingTestCase { |
| private static final Logger log = LoggerFactory.getLogger(ReSeekTestCase.class); |
| |
| /** |
| * Let N be a random number between [0, RESEEK_INTERVAL). After every Nth entry "returned" to the |
| * client, recreate and reseek the iterator. |
| */ |
| private static final int RESEEK_INTERVAL = 4; |
| |
| private final Random random; |
| |
| public ReSeekTestCase() { |
| this.random = new SecureRandom(); |
| } |
| |
| @Override |
| public IteratorTestOutput test(IteratorTestInput testInput) { |
| final SortedKeyValueIterator<Key,Value> skvi = IteratorTestUtil.instantiateIterator(testInput); |
| final SortedKeyValueIterator<Key,Value> source = IteratorTestUtil.createSource(testInput); |
| |
| try { |
| skvi.init(source, testInput.getIteratorOptions(), new SimpleIteratorEnvironment()); |
| skvi.seek(testInput.getRange(), testInput.getFamilies(), testInput.isInclusive()); |
| return new IteratorTestOutput(consume(skvi, testInput)); |
| } catch (IOException e) { |
| return new IteratorTestOutput(e); |
| } |
| } |
| |
| TreeMap<Key,Value> consume(SortedKeyValueIterator<Key,Value> skvi, IteratorTestInput testInput) |
| throws IOException { |
| final TreeMap<Key,Value> data = new TreeMap<>(); |
| final Range origRange = testInput.getRange(); |
| final Collection<ByteSequence> origFamilies = testInput.getFamilies(); |
| final boolean origInclusive = testInput.isInclusive(); |
| int reseekCount = random.nextInt(RESEEK_INTERVAL); |
| |
| int i = 0; |
| while (skvi.hasTop()) { |
| data.put(new Key(skvi.getTopKey()), new Value(skvi.getTopValue())); |
| |
| /* |
| * One of the trickiest cases in writing iterators: After any result is returned from a |
| * TabletServer to the client, the Iterator in the TabletServer's memory may be torn down. To |
| * preserve the state and guarantee that all records are received, the TabletServer does |
| * remember the last Key it returned to the client. It will recreate the Iterator (stack), and |
| * seek it using an updated Range. This range's start key is set to the last Key returned, |
| * non-inclusive. |
| */ |
| if (i % RESEEK_INTERVAL == reseekCount) { |
| // Last key |
| Key reSeekStartKey = skvi.getTopKey(); |
| |
| // Make a new instance of the iterator |
| skvi = IteratorTestUtil.instantiateIterator(testInput); |
| final SortedKeyValueIterator<Key,Value> sourceCopy = |
| IteratorTestUtil.createSource(testInput); |
| |
| skvi.init(sourceCopy, testInput.getIteratorOptions(), new SimpleIteratorEnvironment()); |
| |
| // The new range, resume where we left off (non-inclusive), with same families filter |
| final Range newRange = |
| new Range(reSeekStartKey, false, origRange.getEndKey(), origRange.isEndKeyInclusive()); |
| log.debug("Re-seeking to {}", newRange); |
| |
| // Seek there |
| skvi.seek(newRange, origFamilies, origInclusive); |
| } else { |
| // Every other time, it's a simple call to next() |
| skvi.next(); |
| } |
| |
| i++; |
| } |
| |
| return data; |
| } |
| |
| } |