eagle-core/eagle-query/eagle-entity-base/src/test/java/org/apache/eagle/log/entity/TestDoubleSerDeser.java

/*
 * 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.
 */
package org.apache.eagle.log.entity;

import org.apache.eagle.log.entity.meta.DoubleSerDeser;
import org.apache.eagle.common.ByteUtil;
import org.junit.Assert;
import org.apache.hadoop.hbase.filter.BinaryComparator;
import org.junit.Test;

public class TestDoubleSerDeser {

    @Test
    public void test() {
        DoubleSerDeser dsd = new DoubleSerDeser();
        // byte[] t = {'N', 'a', 'N'};
        byte[] t = dsd.serialize(Double.NaN);

        Double d = dsd.deserialize(t);
        System.out.println(d);
        // Double d = dsd.deserialize(t);
    }

    /**
     * @link http://en.wikipedia.org/wiki/Double-precision_floating-point_format
     */
    @Test
    public void testIEEE754_Binary64_DoublePrecisionFloatingPointFormat() {
        for (Double last = null, i = Math.pow(-2.0, 33); i < Math.pow(2.0, 33); i += Math.pow(2.0, 10)) {
            if (last != null) {
                Assert.assertTrue(i > last);
                if (last < 0 && i < 0) {
                    Assert
                        .assertTrue("Negative double value and its  serialization Binary array have negative correlation",
                                    new BinaryComparator(ByteUtil.doubleToBytes(i))
                                        .compareTo(ByteUtil.doubleToBytes(last)) < 0);
                } else if (last < 0 && i >= 0) {
                    Assert
                        .assertTrue("Binary array for negative double is always greater than any positive doubles' ",
                                    new BinaryComparator(ByteUtil.doubleToBytes(i))
                                        .compareTo(ByteUtil.doubleToBytes(last)) < 0);
                } else if (last >= 0) {
                    Assert
                        .assertTrue("Positive double value and its  serialization Binary array have positive correlation",
                                    new BinaryComparator(ByteUtil.doubleToBytes(i))
                                        .compareTo(ByteUtil.doubleToBytes(last)) > 0);
                }
            }
            last = i;
        }
        Assert.assertTrue("Binary array for negative double is always greater than any positive doubles'",
                          new BinaryComparator(ByteUtil.doubleToBytes(-1.0))
                              .compareTo(ByteUtil.doubleToBytes(Math.pow(2.0, 32))) > 0);
    }
}