org.elasticsearch.test.AbstractWireTestCase Maven / Gradle / Ivy
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/*
* Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
* or more contributor license agreements. Licensed under the Elastic License
* 2.0 and the Server Side Public License, v 1; you may not use this file except
* in compliance with, at your election, the Elastic License 2.0 or the Server
* Side Public License, v 1.
*/
package org.elasticsearch.test;
import org.elasticsearch.TransportVersion;
import org.elasticsearch.common.io.stream.NamedWriteable;
import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
import org.elasticsearch.common.io.stream.Writeable;
import org.elasticsearch.core.Releasable;
import org.elasticsearch.xcontent.ToXContent;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import static org.hamcrest.Matchers.emptyString;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.not;
/**
* Standard test case for testing wire serialization. If the class being tested
* extends {@link Writeable} then prefer extending {@link AbstractWireSerializingTestCase}.
*/
public abstract class AbstractWireTestCase extends ESTestCase {
protected static final int NUMBER_OF_TEST_RUNS = 20;
/**
* Creates a random test instance to use in the tests. This method will be
* called multiple times during test execution and should return a different
* random instance each time it is called.
*/
protected abstract T createTestInstance();
/**
* Returns an instance which is mutated slightly so it should not be equal
* to the given instance.
*/
protected abstract T mutateInstance(T instance) throws IOException;
/**
* Tests that the equals and hashcode methods are consistent and copied
* versions of the instance are equal.
*/
public final void testEqualsAndHashcode() {
for (int runs = 0; runs < NUMBER_OF_TEST_RUNS; runs++) {
T testInstance = createTestInstance();
try {
EqualsHashCodeTestUtils.checkEqualsAndHashCode(testInstance, this::copyInstance, this::mutateInstance, this::dispose);
} finally {
dispose(testInstance);
}
}
}
/**
* Dispose of the copy, usually {@link Releasable#close} or a noop.
*/
protected void dispose(T t) {}
/**
* Calls {@link Object#equals} on equal objects on many threads and verifies
* they all return true. Folks tend to assume this is true about
* {@link Object#equals} and it generally is. But some
* equals implementations violate this assumption and it's very surprising.
* This tries to fail when that assumption is violated.
*/
public final void testConcurrentEquals() throws IOException, InterruptedException, ExecutionException {
T testInstance = createTestInstance();
try {
T copy = copyInstance(testInstance);
try {
/*
* 500 rounds seems to consistently reproduce the issue on Nik's
* laptop. Larger numbers are going to be slower but more likely
* to reproduce the issue.
*/
int rounds = scaledRandomIntBetween(300, 5000);
concurrentTest(() -> {
for (int r = 0; r < rounds; r++) {
assertEquals(testInstance, copy);
}
});
} finally {
dispose(copy);
}
} finally {
dispose(testInstance);
}
}
/**
* Call some test on many threads in parallel.
*/
protected void concurrentTest(Runnable r) throws InterruptedException, ExecutionException {
int threads = 5;
int tasks = threads * 2;
ExecutorService exec = Executors.newFixedThreadPool(threads);
try {
List> results = new ArrayList<>();
for (int t = 0; t < tasks; t++) {
results.add(exec.submit(r));
}
for (Future f : results) {
f.get();
}
} finally {
exec.shutdown();
}
}
/**
* Calls {@link Object#hashCode} on the same object on many threads and
* verifies they return the same result. Folks tend to assume this is true
* about {@link Object#hashCode} and it generally is. But
* some hashCode implementations violate this assumption and it's very
* surprising. This tries to fail when that assumption is violated.
*/
public final void testConcurrentHashCode() throws InterruptedException, ExecutionException {
T testInstance = createTestInstance();
try {
int firstHashCode = testInstance.hashCode();
/*
* 500 rounds seems to consistently reproduce the issue on Nik's
* laptop. Larger numbers are going to be slower but more likely
* to reproduce the issue.
*/
int rounds = scaledRandomIntBetween(300, 5000);
concurrentTest(() -> {
for (int r = 0; r < rounds; r++) {
assertEquals(firstHashCode, testInstance.hashCode());
}
});
} finally {
dispose(testInstance);
}
}
public void testToString() throws Exception {
T testInstance = createTestInstance();
try {
final String toString = testInstance.toString();
assertNotNull(toString);
assertThat(toString, not(emptyString()));
} finally {
dispose(testInstance);
}
}
/**
* Test serialization and deserialization of the test instance.
*/
public final void testSerialization() throws IOException {
for (int runs = 0; runs < NUMBER_OF_TEST_RUNS; runs++) {
T testInstance = createTestInstance();
try {
assertSerialization(testInstance);
} finally {
dispose(testInstance);
}
}
}
/**
* Test serializing the same object on many threads always
* deserializes to equal instances. Folks tend to assume this is true
* about serialization and it generally is. But
* some implementations violate this assumption and it's very
* surprising. This tries to fail when that assumption is violated.
*
* Async search can serialize responses concurrently with other
* operations like {@link ToXContent#toXContent}. This doesn't
* check that exactly, but it's close.
*/
public final void testConcurrentSerialization() throws InterruptedException, ExecutionException {
T testInstance = createTestInstance();
try {
/*
* 500 rounds seems to consistently reproduce the issue on Nik's
* laptop. Larger numbers are going to be slower but more likely
* to reproduce the issue.
*/
int rounds = scaledRandomIntBetween(300, 2000);
concurrentTest(() -> {
try {
for (int r = 0; r < rounds; r++) {
assertSerialization(testInstance);
}
} catch (IOException e) {
throw new AssertionError("error serializing", e);
}
});
} finally {
dispose(testInstance);
}
}
/**
* Serialize the given instance and asserts that both are equal.
*/
protected final void assertSerialization(T testInstance) throws IOException {
assertSerialization(testInstance, TransportVersion.current());
}
/**
* Assert that instances copied at a particular version are equal. The version is useful
* for sanity checking the backwards compatibility of the wire. It isn't a substitute for
* real backwards compatibility tests but it is *so* much faster.
*/
protected final void assertSerialization(T testInstance, TransportVersion version) throws IOException {
T deserializedInstance = copyInstance(testInstance, version);
try {
assertEqualInstances(testInstance, deserializedInstance);
} finally {
dispose(deserializedInstance);
}
}
/**
* Assert that two instances are equal. This is intentionally not final so we can override
* how equality is checked.
*/
protected void assertEqualInstances(T expectedInstance, T newInstance) {
if (shouldBeSame(newInstance)) {
assertSame(newInstance, expectedInstance);
} else {
assertNotSame(newInstance, expectedInstance);
}
assertThat(newInstance, equalTo(expectedInstance));
assertThat(newInstance.hashCode(), equalTo(expectedInstance.hashCode()));
}
/**
* Should this copy be the same instance as what we're copying? Defaults to
* {@code false} but implementers might override if the serialization returns
* a reuse constant.
*/
protected boolean shouldBeSame(T newInstance) {
return false;
}
protected final T copyInstance(T instance) throws IOException {
return copyInstance(instance, TransportVersion.current());
}
/**
* Copy the instance as by reading and writing using the code specific to the provided version.
* The version is useful for sanity checking the backwards compatibility of the wire. It isn't
* a substitute for real backwards compatibility tests but it is *so* much faster.
*/
protected abstract T copyInstance(T instance, TransportVersion version) throws IOException;
/**
* Get the {@link NamedWriteableRegistry} to use when de-serializing the object.
*
* Override this method if you need to register {@link NamedWriteable}s for the test object to de-serialize.
*
* By default this will return a {@link NamedWriteableRegistry} with no registered {@link NamedWriteable}s
*/
protected NamedWriteableRegistry getNamedWriteableRegistry() {
return new NamedWriteableRegistry(Collections.emptyList());
}
}