src/test/java/org/apache/maven/buildcache/checksum/XXHashTest.java

package org.apache.maven.buildcache.checksum;

/*
 * 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.
 */
import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;
import org.apache.maven.buildcache.hash.HashAlgorithm;
import org.apache.maven.buildcache.hash.HashChecksum;
import org.junit.jupiter.api.Test;

import static org.apache.maven.buildcache.hash.HashFactory.XX;
import static org.apache.maven.buildcache.hash.HashFactory.XXMM;
import static org.junit.jupiter.api.Assertions.assertEquals;

public class XXHashTest
{

    private static final byte[] HELLO_ARRAY = "hello".getBytes( StandardCharsets.UTF_8 );

    private static final byte[] WORLD_ARRAY = "world".getBytes( StandardCharsets.UTF_8 );

    private static final long HELLO_LONG = 2794345569481354659L;

    private static final long WORLD_LONG = -1767385783675760145L;

    private static final String EMPTY_HASH = "ef46db3751d8e999";

    private static final String HELLO_HASH = "26c7827d889f6da3";

    private static final String WORLD_HASH = "e778fbfe66ee51ef";

    private static final String HELLO_CHECKSUM = "c07c10338a825a5d";

    private static final String WORLD_CHECKSUM = "cb21505d7a714523";

    private static final String FULL_CHECKSUM = "b8ca8fa824d335e9";

    private static final HashAlgorithm ALGORITHM = XX.createAlgorithm();

    @Test
    public void testEmptyArray()
    {
        byte[] emptyArray = new byte[0];
        String hash = ALGORITHM.hash( emptyArray );
        assertEquals( EMPTY_HASH, hash );
    }

    @Test
    public void testSimpleHash()
    {
        String helloHash = ALGORITHM.hash( HELLO_ARRAY );
        assertEquals( HELLO_HASH, helloHash );

        String worldHash = ALGORITHM.hash( WORLD_ARRAY );
        assertEquals( WORLD_HASH, worldHash );
    }

    @Test
    public void testSimpleChecksum()
    {
        String helloChecksum = ALGORITHM.hash( longToBytes( 1, HELLO_LONG ) );
        assertEquals( HELLO_CHECKSUM, helloChecksum );

        String worldChecksum = ALGORITHM.hash( longToBytes( 1, WORLD_LONG ) );
        assertEquals( WORLD_CHECKSUM, worldChecksum );

        String checksum = ALGORITHM.hash( longToBytes( 2, HELLO_LONG, WORLD_LONG ) );
        assertEquals( FULL_CHECKSUM, checksum );
    }

    @Test
    public void testEmptyBuffer()
    {
        assertEmptyBuffer( XX.createChecksum( 0 ) );
        assertEmptyBuffer( XXMM.createChecksum( 0 ) );
    }

    @Test
    public void testSingleHash()
    {
        assertSingleHash( XX.createChecksum( 1 ) );
        assertSingleHash( XXMM.createChecksum( 1 ) );
    }

    @Test
    public void testSingleChecksum()
    {
        assertSingleChecksum( XX.createChecksum( 1 ) );
        assertSingleChecksum( XXMM.createChecksum( 1 ) );
    }

    @Test
    public void testNotFullChecksum()
    {
        assertSingleChecksum( XX.createChecksum( 2 ) );
        assertSingleChecksum( XXMM.createChecksum( 2 ) );
    }

    @Test
    public void testFullChecksum()
    {
        assertFullChecksum( XX.createChecksum( 2 ) );
        assertFullChecksum( XXMM.createChecksum( 2 ) );
    }

    private void assertEmptyBuffer( HashChecksum checksum )
    {
        assertEquals( EMPTY_HASH, checksum.digest() );
    }

    private void assertSingleHash( HashChecksum checksum )
    {
        assertEquals( HELLO_HASH, checksum.update( HELLO_ARRAY ) );
        assertEquals( HELLO_CHECKSUM, checksum.digest() );
    }

    private void assertSingleChecksum( HashChecksum checksum )
    {
        assertEquals( HELLO_HASH, checksum.update( HELLO_HASH ) );
        assertEquals( HELLO_CHECKSUM, checksum.digest() );
    }

    private void assertFullChecksum( HashChecksum checksum )
    {
        assertEquals( HELLO_HASH, checksum.update( HELLO_HASH ) );
        assertEquals( WORLD_HASH, checksum.update( WORLD_HASH ) );
        assertEquals( FULL_CHECKSUM, checksum.digest() );
    }

    private byte[] longToBytes( int size, long... values )
    {
        final ByteBuffer buffer = ByteBuffer.allocate( size * Long.SIZE / Byte.SIZE );
        for ( long value : values )
        {
            buffer.putLong( value );
        }
        return buffer.array();
    }
}