parquet-column/src/test/java/org/apache/parquet/column/values/bytestreamsplit/ByteStreamSplitValuesReaderTest.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,
 * 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
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package org.apache.parquet.column.values.bytestreamsplit;

import java.io.IOException;
import org.apache.parquet.bytes.ByteBufferInputStream;
import org.apache.parquet.io.ParquetDecodingException;

import static org.junit.Assert.assertEquals;
import org.junit.Test;

import java.nio.ByteBuffer;
import java.util.Random;
import org.junit.Assert;

public class ByteStreamSplitValuesReaderTest {

  public static class FloatTest {

    private void testReader(byte[] input, float[] values) throws IOException {
      ByteBuffer buffer = ByteBuffer.wrap(input);
      ByteBufferInputStream stream = ByteBufferInputStream.wrap(buffer);
      ByteStreamSplitValuesReaderForFloat reader = new ByteStreamSplitValuesReaderForFloat();
      reader.initFromPage(values.length, stream);
      for (float expectedValue : values) {
        float f = reader.readFloat();
        assertEquals(expectedValue, f, 0.0f);
      }
    }

    @Test
    public void testSingleElement() throws Exception {
      byte[] byteData = {(byte) 0x00, (byte) 0x00, (byte) 0x10, (byte) 0x40};
      testReader(byteData, new float[]{2.25f});
    }

    @Test
    public void testSmallBuffer() throws Exception {
      byte[] byteData = {(byte) 0x40, (byte) 0x00, (byte) 0x80, (byte) 0x40, (byte) 0x05, (byte) 0x84,
        (byte) 0xc5, (byte) 0xbd, (byte) 0x32, (byte) 0xc2, (byte) 0x41, (byte) 0x42};
      float expectedValues[] = {-98.62548828125f, 23.62744140625f, 44.62939453125f};
      testReader(byteData, expectedValues);
    }

    @Test
    public void testRandomInput() throws Exception {
      Random rand = new Random(1337);
      final int numElements = 256;
      byte[] byteData = new byte[numElements * 4];
      float[] values = new float[numElements];
      for (int i = 0; i < numElements; ++i) {
        float f = rand.nextFloat() * 1024.0f;
        values[i] = f;
        int fAsInt = Float.floatToIntBits(f);
        byteData[i] = (byte) (fAsInt & 0xFF);
        byteData[numElements + i] = (byte) ((fAsInt >> 8) & 0xFF);
        byteData[numElements * 2 + i] = (byte) ((fAsInt >> 16) & 0xFF);
        byteData[numElements * 3 + i] = (byte) ((fAsInt >> 24) & 0xFF);
      }
      testReader(byteData, values);
    }

    @Test
    public void testExtraReads() throws Exception {
      byte[] byteData = {(byte) 0x00, (byte) 0x00, (byte) 0x10, (byte) 0x40};
      ByteBuffer buffer = ByteBuffer.wrap(byteData);
      ByteBufferInputStream stream = ByteBufferInputStream.wrap(buffer);

      ByteStreamSplitValuesReaderForFloat reader = new ByteStreamSplitValuesReaderForFloat();
      reader.initFromPage(1, stream);
      float f = reader.readFloat();
      assertEquals(2.25f, f, 0.0f);
      try {
        reader.readFloat();
        Assert.fail("Expected an exception.");
      } catch (ParquetDecodingException ex) {}
    }

    @Test
    public void testSkip() throws Exception {
      byte[] byteData = new byte[16];
      for (int i = 0; i < 16; ++i) {
        byteData[i] = (byte) 0xFF;
      }
      byteData[3] = (byte) 0x00;
      byteData[7] = (byte) 0x00;
      byteData[11] = (byte) 0x10;
      byteData[15] = (byte) 0x40;
      ByteBuffer buffer = ByteBuffer.wrap(byteData);
      ByteBufferInputStream stream = ByteBufferInputStream.wrap(buffer);

      ByteStreamSplitValuesReaderForFloat reader = new ByteStreamSplitValuesReaderForFloat();
      reader.initFromPage(4, stream);
      reader.skip(3);
      float f = reader.readFloat();
      assertEquals(2.25f, f, 0.0f);
    }

    @Test
    public void testSkipOverflow() throws Exception {
      byte[] byteData = new byte[128];
      ByteBuffer buffer = ByteBuffer.wrap(byteData);
      ByteBufferInputStream stream = ByteBufferInputStream.wrap(buffer);

      ByteStreamSplitValuesReaderForFloat reader = new ByteStreamSplitValuesReaderForFloat();
      reader.initFromPage(32, stream);

      try {
        reader.skip(33);
        Assert.fail("Expected an exception.");
      } catch (ParquetDecodingException ex) {}
    }

    @Test
    public void testSkipUnderflow() throws Exception {
      byte[] byteData = new byte[128];
      ByteBuffer buffer = ByteBuffer.wrap(byteData);
      ByteBufferInputStream stream = ByteBufferInputStream.wrap(buffer);

      ByteStreamSplitValuesReaderForFloat reader = new ByteStreamSplitValuesReaderForFloat();
      reader.initFromPage(32, stream);

      try {
        reader.skip(-1);
        Assert.fail("Expected an exception.");
      } catch (ParquetDecodingException ex) {}
    }
  }

  public static class DoubleTest {

    private void testReader(byte[] input, double[] values) throws IOException {
      ByteBuffer buffer = ByteBuffer.wrap(input);
      ByteBufferInputStream stream = ByteBufferInputStream.wrap(buffer);
      ByteStreamSplitValuesReaderForDouble reader = new ByteStreamSplitValuesReaderForDouble();
      reader.initFromPage(values.length, stream);
      for (double expectedValue : values) {
        double d = reader.readDouble();
        assertEquals(expectedValue, d, 0.0);
      }
    }

    @Test
    public void testSingleElement() throws Exception {
      byte[] byteData = {(byte) 0xFE, (byte) 0xFF, (byte) 0xFF, (byte) 0x0D, (byte) 0xA8, (byte) 0x77,
        (byte) 0xD2, (byte) 0x40};
      testReader(byteData, new double[]{18910.62585449218});
    }

    @Test
    public void testSmallBuffer() throws Exception {
      byte[] byteData = {(byte) 0xE7, (byte) 0x72, (byte) 0xBE, (byte) 0x09, (byte) 0xA1, (byte) 0xC1,
        (byte) 0x0A, (byte) 0x0A, (byte) 0x17, (byte) 0xD7, (byte) 0x21, (byte) 0x26, (byte) 0x01,
        (byte) 0xC7, (byte) 0x53, (byte) 0x0A, (byte) 0x46, (byte) 0x05, (byte) 0x70, (byte) 0xF3,
        (byte) 0xE4, (byte) 0x40, (byte) 0xC0, (byte) 0x3F};
      double expectedValues[] = {256.625449218, -78956.4455667788, 0.62565};
      testReader(byteData, expectedValues);
    }

    @Test
    public void testRandomInput() throws Exception {
      Random rand = new Random(6557);
      final int numElements = 256;
      byte[] byteData = new byte[numElements * 8];
      double[] values = new double[numElements];
      for (int i = 0; i < numElements; ++i) {
        double f = rand.nextDouble() * 8192.0;
        values[i] = f;
        long fAsLong = Double.doubleToLongBits(f);
        for (int j = 0; j < 8; ++j) {
          byteData[numElements * j + i] = (byte) ((fAsLong >> (8 * j)) & 0xFF);
        }
      }
      testReader(byteData, values);
    }
  }
}