/*
* 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.beam.sdk.transforms;
import static org.hamcrest.Matchers.anyOf;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.greaterThan;
import static org.hamcrest.Matchers.is;
import static org.junit.Assert.assertThat;
import static org.junit.Assert.fail;
import java.io.Serializable;
import java.util.concurrent.atomic.AtomicBoolean;
import org.apache.beam.sdk.testing.NeedsRunner;
import org.apache.beam.sdk.testing.TestPipeline;
import org.apache.beam.sdk.testing.ValidatesRunner;
import org.apache.beam.sdk.values.PCollectionList;
import org.apache.beam.sdk.values.TupleTag;
import org.apache.beam.sdk.values.TupleTagList;
import org.junit.Rule;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;
/**
* Tests that {@link ParDo} exercises {@link DoFn} methods in the appropriate sequence.
*/
@RunWith(JUnit4.class)
public class ParDoLifecycleTest implements Serializable {
@Rule
public final transient TestPipeline p = TestPipeline.create();
@Test
@Category(ValidatesRunner.class)
public void testOldFnCallSequence() {
PCollectionList.of(p.apply("Impolite", Create.of(1, 2, 4)))
.and(p.apply("Polite", Create.of(3, 5, 6, 7)))
.apply(Flatten.<Integer>pCollections())
.apply(ParDo.of(new CallSequenceEnforcingDoFn<Integer>()));
p.run();
}
@Test
@Category(ValidatesRunner.class)
public void testOldFnCallSequenceMulti() {
PCollectionList.of(p.apply("Impolite", Create.of(1, 2, 4)))
.and(p.apply("Polite", Create.of(3, 5, 6, 7)))
.apply(Flatten.<Integer>pCollections())
.apply(ParDo.of(new CallSequenceEnforcingDoFn<Integer>())
.withOutputTags(new TupleTag<Integer>() {}, TupleTagList.empty()));
p.run();
}
private static class CallSequenceEnforcingDoFn<T> extends DoFn<T, T> {
private boolean setupCalled = false;
private int startBundleCalls = 0;
private int finishBundleCalls = 0;
private boolean teardownCalled = false;
@Setup
public void setup() {
assertThat("setup should not be called twice", setupCalled, is(false));
assertThat("setup should be called before startBundle", startBundleCalls, equalTo(0));
assertThat("setup should be called before finishBundle", finishBundleCalls, equalTo(0));
assertThat("setup should be called before teardown", teardownCalled, is(false));
setupCalled = true;
}
@StartBundle
public void startBundle() {
assertThat("setup should have been called", setupCalled, is(true));
assertThat(
"Even number of startBundle and finishBundle calls in startBundle",
startBundleCalls,
equalTo(finishBundleCalls));
assertThat("teardown should not have been called", teardownCalled, is(false));
startBundleCalls++;
}
@ProcessElement
public void processElement(ProcessContext c) throws Exception {
assertThat("startBundle should have been called", startBundleCalls, greaterThan(0));
assertThat(
"there should be one startBundle call with no call to finishBundle",
startBundleCalls,
equalTo(finishBundleCalls + 1));
assertThat("teardown should not have been called", teardownCalled, is(false));
}
@FinishBundle
public void finishBundle() {
assertThat("startBundle should have been called", startBundleCalls, greaterThan(0));
assertThat(
"there should be one bundle that has been started but not finished",
startBundleCalls,
equalTo(finishBundleCalls + 1));
assertThat("teardown should not have been called", teardownCalled, is(false));
finishBundleCalls++;
}
@Teardown
public void teardown() {
assertThat(setupCalled, is(true));
assertThat(startBundleCalls, anyOf(equalTo(finishBundleCalls)));
assertThat(teardownCalled, is(false));
teardownCalled = true;
}
}
@Test
@Category(ValidatesRunner.class)
public void testFnCallSequence() {
PCollectionList.of(p.apply("Impolite", Create.of(1, 2, 4)))
.and(p.apply("Polite", Create.of(3, 5, 6, 7)))
.apply(Flatten.<Integer>pCollections())
.apply(ParDo.of(new CallSequenceEnforcingFn<Integer>()));
p.run();
}
@Test
@Category(ValidatesRunner.class)
public void testFnCallSequenceMulti() {
PCollectionList.of(p.apply("Impolite", Create.of(1, 2, 4)))
.and(p.apply("Polite", Create.of(3, 5, 6, 7)))
.apply(Flatten.<Integer>pCollections())
.apply(ParDo.of(new CallSequenceEnforcingFn<Integer>())
.withOutputTags(new TupleTag<Integer>() {
}, TupleTagList.empty()));
p.run();
}
private static class CallSequenceEnforcingFn<T> extends DoFn<T, T> {
private boolean setupCalled = false;
private int startBundleCalls = 0;
private int finishBundleCalls = 0;
private boolean teardownCalled = false;
@Setup
public void before() {
assertThat("setup should not be called twice", setupCalled, is(false));
assertThat("setup should be called before startBundle", startBundleCalls, equalTo(0));
assertThat("setup should be called before finishBundle", finishBundleCalls, equalTo(0));
assertThat("setup should be called before teardown", teardownCalled, is(false));
setupCalled = true;
}
@StartBundle
public void begin() {
assertThat("setup should have been called", setupCalled, is(true));
assertThat("Even number of startBundle and finishBundle calls in startBundle",
startBundleCalls,
equalTo(finishBundleCalls));
assertThat("teardown should not have been called", teardownCalled, is(false));
startBundleCalls++;
}
@ProcessElement
public void process(ProcessContext c) throws Exception {
assertThat("startBundle should have been called", startBundleCalls, greaterThan(0));
assertThat("there should be one startBundle call with no call to finishBundle",
startBundleCalls,
equalTo(finishBundleCalls + 1));
assertThat("teardown should not have been called", teardownCalled, is(false));
}
@FinishBundle
public void end() {
assertThat("startBundle should have been called", startBundleCalls, greaterThan(0));
assertThat("there should be one bundle that has been started but not finished",
startBundleCalls,
equalTo(finishBundleCalls + 1));
assertThat("teardown should not have been called", teardownCalled, is(false));
finishBundleCalls++;
}
@Teardown
public void after() {
assertThat(setupCalled, is(true));
assertThat(startBundleCalls, anyOf(equalTo(finishBundleCalls)));
assertThat(teardownCalled, is(false));
teardownCalled = true;
}
}
@Test
@Category(NeedsRunner.class)
public void testTeardownCalledAfterExceptionInSetup() {
ExceptionThrowingOldFn fn = new ExceptionThrowingOldFn(MethodForException.SETUP);
p
.apply(Create.of(1, 2, 3))
.apply(ParDo.of(fn));
try {
p.run();
fail("Pipeline should have failed with an exception");
} catch (Exception e) {
assertThat(
"Function should have been torn down after exception",
ExceptionThrowingOldFn.teardownCalled.get(),
is(true));
}
}
@Test
@Category(NeedsRunner.class)
public void testTeardownCalledAfterExceptionInStartBundle() {
ExceptionThrowingOldFn fn = new ExceptionThrowingOldFn(MethodForException.START_BUNDLE);
p
.apply(Create.of(1, 2, 3))
.apply(ParDo.of(fn));
try {
p.run();
fail("Pipeline should have failed with an exception");
} catch (Exception e) {
assertThat(
"Function should have been torn down after exception",
ExceptionThrowingOldFn.teardownCalled.get(),
is(true));
}
}
@Test
@Category(NeedsRunner.class)
public void testTeardownCalledAfterExceptionInProcessElement() {
ExceptionThrowingOldFn fn = new ExceptionThrowingOldFn(MethodForException.PROCESS_ELEMENT);
p
.apply(Create.of(1, 2, 3))
.apply(ParDo.of(fn));
try {
p.run();
fail("Pipeline should have failed with an exception");
} catch (Exception e) {
assertThat(
"Function should have been torn down after exception",
ExceptionThrowingOldFn.teardownCalled.get(),
is(true));
}
}
@Test
@Category(NeedsRunner.class)
public void testTeardownCalledAfterExceptionInFinishBundle() {
ExceptionThrowingOldFn fn = new ExceptionThrowingOldFn(MethodForException.FINISH_BUNDLE);
p
.apply(Create.of(1, 2, 3))
.apply(ParDo.of(fn));
try {
p.run();
fail("Pipeline should have failed with an exception");
} catch (Exception e) {
assertThat(
"Function should have been torn down after exception",
ExceptionThrowingOldFn.teardownCalled.get(),
is(true));
}
}
@Test
@Category(NeedsRunner.class)
public void testWithContextTeardownCalledAfterExceptionInSetup() {
ExceptionThrowingOldFn fn = new ExceptionThrowingOldFn(MethodForException.SETUP);
p.apply(Create.of(1, 2, 3)).apply(ParDo.of(fn));
try {
p.run();
fail("Pipeline should have failed with an exception");
} catch (Exception e) {
assertThat("Function should have been torn down after exception",
ExceptionThrowingOldFn.teardownCalled.get(),
is(true));
}
}
@Test
@Category(NeedsRunner.class)
public void testWithContextTeardownCalledAfterExceptionInStartBundle() {
ExceptionThrowingOldFn fn = new ExceptionThrowingOldFn(MethodForException.START_BUNDLE);
p.apply(Create.of(1, 2, 3)).apply(ParDo.of(fn));
try {
p.run();
fail("Pipeline should have failed with an exception");
} catch (Exception e) {
assertThat("Function should have been torn down after exception",
ExceptionThrowingOldFn.teardownCalled.get(),
is(true));
}
}
@Test
@Category(NeedsRunner.class)
public void testWithContextTeardownCalledAfterExceptionInProcessElement() {
ExceptionThrowingOldFn fn = new ExceptionThrowingOldFn(MethodForException.PROCESS_ELEMENT);
p.apply(Create.of(1, 2, 3)).apply(ParDo.of(fn));
try {
p.run();
fail("Pipeline should have failed with an exception");
} catch (Exception e) {
assertThat("Function should have been torn down after exception",
ExceptionThrowingOldFn.teardownCalled.get(),
is(true));
}
}
@Test
@Category(NeedsRunner.class)
public void testWithContextTeardownCalledAfterExceptionInFinishBundle() {
ExceptionThrowingOldFn fn = new ExceptionThrowingOldFn(MethodForException.FINISH_BUNDLE);
p.apply(Create.of(1, 2, 3)).apply(ParDo.of(fn));
try {
p.run();
fail("Pipeline should have failed with an exception");
} catch (Exception e) {
assertThat("Function should have been torn down after exception",
ExceptionThrowingOldFn.teardownCalled.get(),
is(true));
}
}
private static class ExceptionThrowingOldFn extends DoFn<Object, Object> {
static AtomicBoolean teardownCalled = new AtomicBoolean(false);
private final MethodForException toThrow;
private boolean thrown;
private ExceptionThrowingOldFn(MethodForException toThrow) {
this.toThrow = toThrow;
}
@Setup
public void setup() throws Exception {
throwIfNecessary(MethodForException.SETUP);
}
@StartBundle
public void startBundle() throws Exception {
throwIfNecessary(MethodForException.START_BUNDLE);
}
@ProcessElement
public void processElement(ProcessContext c) throws Exception {
throwIfNecessary(MethodForException.PROCESS_ELEMENT);
}
@FinishBundle
public void finishBundle() throws Exception {
throwIfNecessary(MethodForException.FINISH_BUNDLE);
}
private void throwIfNecessary(MethodForException method) throws Exception {
if (toThrow == method && !thrown) {
thrown = true;
throw new Exception("Hasn't yet thrown");
}
}
@Teardown
public void teardown() {
if (!thrown) {
fail("Excepted to have a processing method throw an exception");
}
teardownCalled.set(true);
}
}
private static class ExceptionThrowingFn extends DoFn<Object, Object> {
static AtomicBoolean teardownCalled = new AtomicBoolean(false);
private final MethodForException toThrow;
private boolean thrown;
private ExceptionThrowingFn(MethodForException toThrow) {
this.toThrow = toThrow;
}
@Setup
public void before() throws Exception {
throwIfNecessary(MethodForException.SETUP);
}
@StartBundle
public void preBundle() throws Exception {
throwIfNecessary(MethodForException.START_BUNDLE);
}
@ProcessElement
public void perElement(ProcessContext c) throws Exception {
throwIfNecessary(MethodForException.PROCESS_ELEMENT);
}
@FinishBundle
public void postBundle() throws Exception {
throwIfNecessary(MethodForException.FINISH_BUNDLE);
}
private void throwIfNecessary(MethodForException method) throws Exception {
if (toThrow == method && !thrown) {
thrown = true;
throw new Exception("Hasn't yet thrown");
}
}
@Teardown
public void after() {
if (!thrown) {
fail("Excepted to have a processing method throw an exception");
}
teardownCalled.set(true);
}
}
private enum MethodForException {
SETUP,
START_BUNDLE,
PROCESS_ELEMENT,
FINISH_BUNDLE
}
}