fe/fe-core/src/test/java/org/apache/doris/catalog/ColumnStatTest.java

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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,
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package org.apache.doris.catalog;

import org.apache.doris.common.io.Text;
import org.apache.doris.persist.gson.GsonUtils;

import org.junit.Assert;
import org.junit.Test;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

public class ColumnStatTest {

    @Test
    public void testSerialization() throws Exception {
        // 1. Write objects to file
        Path path = Files.createFile(Paths.get("./columnStats"));
        DataOutputStream dos = new DataOutputStream(Files.newOutputStream(path));

        ColumnStats stats1 = new ColumnStats();
        Text.writeString(dos, GsonUtils.GSON.toJson(stats1));

        ColumnStats stats2 = new ColumnStats();
        stats2.setAvgSerializedSize(1.1f);
        stats2.setNumDistinctValues(100L);
        stats2.setMaxSize(1000L);
        stats2.setNumNulls(10000L);
        Text.writeString(dos, GsonUtils.GSON.toJson(stats2));

        ColumnStats stats3 = new ColumnStats();
        stats3.setAvgSerializedSize(3.3f);
        stats3.setNumDistinctValues(200L);
        stats3.setMaxSize(2000L);
        stats3.setNumNulls(20000L);
        Text.writeString(dos, GsonUtils.GSON.toJson(stats3));

        ColumnStats stats4 = new ColumnStats(stats3);
        Text.writeString(dos, GsonUtils.GSON.toJson(stats4));

        dos.flush();
        dos.close();

        // 2. Read objects from file
        DataInputStream dis = new DataInputStream(Files.newInputStream(path));
        ColumnStats rStats1 = GsonUtils.GSON.fromJson(Text.readString(dis), ColumnStats.class);
        Assert.assertEquals(rStats1, stats1);

        ColumnStats rStats2 = GsonUtils.GSON.fromJson(Text.readString(dis), ColumnStats.class);
        Assert.assertEquals(rStats2, stats2);

        ColumnStats rStats3 = GsonUtils.GSON.fromJson(Text.readString(dis), ColumnStats.class);
        Assert.assertEquals(rStats3, stats3);

        ColumnStats rStats4 = GsonUtils.GSON.fromJson(Text.readString(dis), ColumnStats.class);
        Assert.assertEquals(rStats4, stats4);
        Assert.assertEquals(rStats4, stats3);

        Assert.assertEquals(rStats3, rStats3);
        Assert.assertNotEquals(rStats3, this);
        Assert.assertNotEquals(rStats2, rStats3);

        // 3. delete files
        dis.close();
        Files.deleteIfExists(path);
    }

}