cassandra-trunk/test/unit/org/apache/cassandra/dht/Murmur3PartitionerTest.java
/*
 * Licensed to the Apache Software Foundation (ASF) under one
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 * 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,
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 * See the License for the specific language governing permissions and
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package org.apache.cassandra.dht;

import java.nio.ByteBuffer;

import org.junit.Test;

import static org.quicktheories.QuickTheory.qt;
import static org.quicktheories.generators.SourceDSL.longs;

public class Murmur3PartitionerTest extends PartitionerTestCase
{
    public void initPartitioner()
    {
        partitioner = Murmur3Partitioner.instance;
    }

    @Override
    protected void midpointMinimumTestCase()
    {
        Token mintoken = partitioner.getMinimumToken();
        assert mintoken.compareTo(partitioner.midpoint(mintoken, mintoken)) != 0;
        assertMidpoint(mintoken, tok("a"), 16);
        assertMidpoint(mintoken, tok("aaa"), 16);
        assertMidpoint(mintoken, mintoken, 62);
        assertMidpoint(tok("a"), mintoken, 16);
    }

    protected boolean shouldStopRecursion(Token left, Token right)
    {
        return left.size(right) < Math.scalb(1, -48);
    }

    @Test
    public void testSplit()
    {
        assertSplit(tok("a"), tok("b"), 16);
        assertSplit(tok("a"), tok("bbb"), 16);
    }

    @Test
    public void testSplitWrapping()
    {
        assertSplit(tok("b"), tok("a"), 16);
        assertSplit(tok("bbb"), tok("a"), 16);
    }

    @Test
    public void testSplitExceedMaximumCase()
    {
        Murmur3Partitioner.LongToken left = new Murmur3Partitioner.LongToken(Long.MAX_VALUE - 100);
        assertSplit(left, tok("a"), 16);
    }

    @Test
    public void testLongTokenInverse()
    {
        qt().forAll(longs().between(Long.MIN_VALUE + 1, Long.MAX_VALUE))
            .check(token -> {
                ByteBuffer key = Murmur3Partitioner.LongToken.keyForToken(new Murmur3Partitioner.LongToken(token));
                return Murmur3Partitioner.instance.getToken(key).token == token;
            });
    }
}

