/*
* 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.flink.runtime.operators.resettable;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.NoSuchElementException;
import org.apache.flink.api.common.typeutils.TypeSerializer;
import org.apache.flink.api.common.typeutils.base.IntValueSerializer;
import org.apache.flink.runtime.io.disk.iomanager.IOManager;
import org.apache.flink.runtime.jobgraph.tasks.AbstractInvokable;
import org.apache.flink.runtime.memorymanager.DefaultMemoryManager;
import org.apache.flink.runtime.memorymanager.MemoryManager;
import org.apache.flink.runtime.operators.testutils.DummyInvokable;
import org.apache.flink.types.IntValue;
import org.junit.Assert;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
public class SpillingResettableIteratorTest {
private static final int NUM_TESTRECORDS = 50000;
private static final int MEMORY_CAPACITY = 10 * 1024 * 1024;
private final AbstractInvokable memOwner = new DummyInvokable();
private IOManager ioman;
private MemoryManager memman;
private Iterator<IntValue> reader;
private final TypeSerializer<IntValue> serializer = new IntValueSerializer();
@Before
public void startup() {
// set up IO and memory manager
this.memman = new DefaultMemoryManager(MEMORY_CAPACITY, 32 * 1024);
this.ioman = new IOManager();
// create test objects
ArrayList<IntValue> objects = new ArrayList<IntValue>(NUM_TESTRECORDS);
for (int i = 0; i < NUM_TESTRECORDS; ++i) {
IntValue tmp = new IntValue(i);
objects.add(tmp);
}
this.reader = objects.iterator();
}
@After
public void shutdown() {
this.ioman.shutdown();
if (!this.ioman.isProperlyShutDown()) {
Assert.fail("I/O Manager Shutdown was not completed properly.");
}
this.ioman = null;
if (!this.memman.verifyEmpty()) {
Assert.fail("A memory leak has occurred: Not all memory was properly returned to the memory manager.");
}
this.memman.shutdown();
this.memman = null;
}
/**
* Tests the resettable iterator with too few memory, so that the data
* has to be written to disk.
*/
@Test
public void testResettableIterator() {
try {
// create the resettable Iterator
SpillingResettableIterator<IntValue> iterator = new SpillingResettableIterator<IntValue>(
this.reader, this.serializer, this.memman, this.ioman, 2, this.memOwner);
// open the iterator
iterator.open();
// now test walking through the iterator
int count = 0;
while (iterator.hasNext()) {
Assert.assertEquals("In initial run, element " + count + " does not match expected value!", count++,
iterator.next().getValue());
}
Assert.assertEquals("Too few elements were deserialzied in initial run!", NUM_TESTRECORDS, count);
// test resetting the iterator a few times
for (int j = 0; j < 10; ++j) {
count = 0;
iterator.reset();
// now we should get the same results
while (iterator.hasNext()) {
Assert.assertEquals("After reset nr. " + j + 1 + " element " + count
+ " does not match expected value!", count++, iterator.next().getValue());
}
Assert.assertEquals("Too few elements were deserialzied after reset nr. " + j + 1 + "!", NUM_TESTRECORDS,
count);
}
// close the iterator
iterator.close();
} catch (Exception ex) {
ex.printStackTrace();
Assert.fail("Test encountered an exception.");
}
}
/**
* Tests the resettable iterator with enough memory so that all data
* is kept locally in a membuffer.
*/
@Test
public void testResettableIteratorInMemory() {
try {
// create the resettable Iterator
SpillingResettableIterator<IntValue> iterator = new SpillingResettableIterator<IntValue>(
this.reader, this.serializer, this.memman, this.ioman, 20, this.memOwner);
// open the iterator
iterator.open();
// now test walking through the iterator
int count = 0;
while (iterator.hasNext()) {
Assert.assertEquals("In initial run, element " + count + " does not match expected value!", count++,
iterator.next().getValue());
}
Assert.assertEquals("Too few elements were deserialzied in initial run!", NUM_TESTRECORDS, count);
// test resetting the iterator a few times
for (int j = 0; j < 10; ++j) {
count = 0;
iterator.reset();
// now we should get the same results
while (iterator.hasNext()) {
Assert.assertEquals("After reset nr. " + j + 1 + " element " + count
+ " does not match expected value!", count++, iterator.next().getValue());
}
Assert.assertEquals("Too few elements were deserialzied after reset nr. " + j + 1 + "!", NUM_TESTRECORDS,
count);
}
// close the iterator
iterator.close();
} catch (Exception ex) {
ex.printStackTrace();
Assert.fail("Test encountered an exception.");
}
}
/**
* Tests whether multiple call of hasNext() changes the state of the iterator
*/
@Test
public void testHasNext() {
try {
// create the resettable Iterator
SpillingResettableIterator<IntValue> iterator = new SpillingResettableIterator<IntValue>(
this.reader, this.serializer, this.memman, this.ioman, 2, this.memOwner);
// open the iterator
iterator.open();
int cnt = 0;
while (iterator.hasNext()) {
iterator.hasNext();
iterator.next();
cnt++;
}
Assert.assertTrue(cnt + " elements read from iterator, but " + NUM_TESTRECORDS + " expected",
cnt == NUM_TESTRECORDS);
iterator.close();
} catch (Exception ex) {
ex.printStackTrace();
Assert.fail("Test encountered an exception.");
}
}
/**
* Test whether next() depends on previous call of hasNext()
*/
@Test
public void testNext() {
try {
// create the resettable Iterator
SpillingResettableIterator<IntValue> iterator = new SpillingResettableIterator<IntValue>(
this.reader, this.serializer, this.memman, this.ioman, 2, this.memOwner);
// open the iterator
iterator.open();
IntValue record;
int cnt = 0;
while (cnt < NUM_TESTRECORDS) {
record = iterator.next();
Assert.assertTrue("Record was not read from iterator", record != null);
cnt++;
}
try {
record = iterator.next();
Assert.fail("Too many records were read from iterator.");
} catch (NoSuchElementException nseex) {
// expected
}
iterator.close();
} catch (Exception ex) {
ex.printStackTrace();
Assert.fail("Test encountered an exception.");
}
}
}