org.opensearch.test.DiffableTestUtils Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of framework Show documentation
OpenSearch subproject :test:framework
There is a newer version: 2.18.0
/*
 * SPDX-License-Identifier: Apache-2.0
 *
 * The OpenSearch Contributors require contributions made to
 * this file be licensed under the Apache-2.0 license or a
 * compatible open source license.
 */

/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch 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.
 */

/*
 * Modifications Copyright OpenSearch Contributors. See
 * GitHub history for details.
 */

package org.opensearch.test;

import org.opensearch.cluster.Diff;
import org.opensearch.cluster.Diffable;
import org.opensearch.common.io.stream.BytesStreamOutput;
import org.opensearch.common.io.stream.NamedWriteableAwareStreamInput;
import org.opensearch.common.io.stream.NamedWriteableRegistry;
import org.opensearch.common.io.stream.StreamInput;
import org.opensearch.common.io.stream.Writeable;
import org.opensearch.common.io.stream.Writeable.Reader;

import java.io.IOException;
import java.util.function.Function;
import java.util.function.Supplier;

import static org.opensearch.test.AbstractWireSerializingTestCase.NUMBER_OF_TEST_RUNS;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotSame;

/**
 * Utilities that simplify testing of diffable classes
 */
public final class DiffableTestUtils {
    protected static final int NUMBER_OF_DIFF_TEST_RUNS = NUMBER_OF_TEST_RUNS;

    private DiffableTestUtils() {

    }

    /**
     * Asserts that changes are applied correctly, i.e. that applying diffs to localInstance produces that object
     * equal but not the same as the remoteChanges instance.
     */
    public static > T assertDiffApplication(T remoteChanges, T localInstance, Diff diffs) {
        T localChanges = diffs.apply(localInstance);
        assertEquals(remoteChanges, localChanges);
        assertEquals(remoteChanges.hashCode(), localChanges.hashCode());
        assertNotSame(remoteChanges, localChanges);
        return localChanges;
    }

    /**
     * Simulates sending diffs over the wire
     */
    public static  T copyInstance(T diffs, NamedWriteableRegistry namedWriteableRegistry,
                                                                  Reader reader) throws IOException {
        try (BytesStreamOutput output = new BytesStreamOutput()) {
            diffs.writeTo(output);
            try (StreamInput in = new NamedWriteableAwareStreamInput(output.bytes().streamInput(), namedWriteableRegistry)) {
                return reader.read(in);
            }
        }
    }

    /**
     * Tests making random changes to an object, calculating diffs for these changes, sending this
     * diffs over the wire and appling these diffs on the other side.
     */
    public static > void testDiffableSerialization(Supplier testInstance,
                                                                         Function modifier,
                                                                         NamedWriteableRegistry namedWriteableRegistry,
                                                                         Reader reader,
                                                                         Reader> diffReader) throws IOException {
        T remoteInstance = testInstance.get();
        T localInstance = assertSerialization(remoteInstance, namedWriteableRegistry, reader);
        for (int runs = 0; runs < NUMBER_OF_DIFF_TEST_RUNS; runs++) {
            T remoteChanges = modifier.apply(remoteInstance);
            Diff remoteDiffs = remoteChanges.diff(remoteInstance);
            Diff localDiffs = copyInstance(remoteDiffs, namedWriteableRegistry, diffReader);
            localInstance = assertDiffApplication(remoteChanges, localInstance, localDiffs);
            remoteInstance = remoteChanges;
        }
    }

    /**
     * Asserts that testInstance can be correctly.
     */
    public static   T assertSerialization(T testInstance, NamedWriteableRegistry namedWriteableRegistry,
                                                          Reader reader) throws IOException {
        T deserializedInstance = copyInstance(testInstance, namedWriteableRegistry, reader);
        assertEquals(testInstance, deserializedInstance);
        assertEquals(testInstance.hashCode(), deserializedInstance.hashCode());
        assertNotSame(testInstance, deserializedInstance);
        return deserializedInstance;
    }

}