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// Copyright 2015 The Bazel Authors. All rights reserved.
//
// Licensed 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 com.google.devtools.build.skyframe;
import static com.google.common.truth.Truth.assertThat;
import com.google.common.collect.ImmutableClassToInstanceMap;
import com.google.devtools.build.lib.skyframe.serialization.DeserializationContext;
import com.google.devtools.build.lib.skyframe.serialization.SerializationContext;
import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
import com.google.devtools.build.lib.skyframe.serialization.testutils.TestUtils;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;
/** Unit test for the SkyKey class, checking hash code transience logic. */
@RunWith(JUnit4.class)
public final class SkyKeyTest {
@Test
@SuppressWarnings("ReturnValueIgnored") // Testing interactions with spy.
public void testHashCodeTransience() throws Exception {
// Given a freshly constructed HashCodeSpy object,
HashCodeSpy hashCodeSpy = new HashCodeSpy();
assertThat(hashCodeSpy.numberOfTimesHashCodeCalled).isEqualTo(0);
// When a SkyKey is constructed with that HashCodeSpy as its argument,
SkyKey originalKey = new HashCodeSpyKey(hashCodeSpy);
// Then the HashCodeSpy reports that its hashcode method was called once.
assertThat(hashCodeSpy.numberOfTimesHashCodeCalled).isEqualTo(1);
// When the SkyKey's hashCode method is called,
originalKey.hashCode();
// Then the spy's hashCode method isn't called, because the SkyKey's hashCode was cached.
assertThat(hashCodeSpy.numberOfTimesHashCodeCalled).isEqualTo(1);
// When that SkyKey is serialized and then deserialized,
SkyKey newKey =
(SkyKey)
TestUtils.fromBytes(
new DeserializationContext(ImmutableClassToInstanceMap.of()),
TestUtils.toBytes(
new SerializationContext(ImmutableClassToInstanceMap.of()), originalKey));
// Then the new SkyKey recomputed its hashcode on deserialization.
assertThat(newKey.hashCode()).isEqualTo(originalKey.hashCode());
HashCodeSpy spyInNewKey = (HashCodeSpy) newKey.argument();
assertThat(spyInNewKey.numberOfTimesHashCodeCalled).isEqualTo(1);
// When the new SkyKey's hashCode method is called,
newKey.hashCode();
// Then the new SkyKey's spy's hashCode method is not called again.
assertThat(spyInNewKey.numberOfTimesHashCodeCalled).isEqualTo(1);
}
static final class HashCodeSpy {
private transient int numberOfTimesHashCodeCalled;
@Override
public int hashCode() {
numberOfTimesHashCodeCalled++;
return 42;
}
// Implemented so that numberOfTimesHashCodeCalled is not incremented when the debugger calls
// toString() - the default Object#toString() calls hashCode().
@Override
public String toString() {
return String.format("HashCodeSpy{count=%s}", numberOfTimesHashCodeCalled);
}
}
@AutoCodec
static final class HashCodeSpyKey extends AbstractSkyKey.WithCachedHashCode<HashCodeSpy> {
HashCodeSpyKey(HashCodeSpy arg) {
super(arg);
}
@Override
public SkyFunctionName functionName() {
return SkyFunctionName.FOR_TESTING;
}
}
}