TestUncheckedByteArrays.java
/*
* Licensed 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 com.facebook.presto.operator;
import com.google.common.primitives.Bytes;
import org.testng.annotations.Test;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.ThreadLocalRandom;
import java.util.function.BiFunction;
import java.util.stream.Collectors;
import java.util.stream.IntStream;
import java.util.stream.LongStream;
import static com.facebook.presto.testing.assertions.Assert.assertEquals;
import static sun.misc.Unsafe.ARRAY_BYTE_INDEX_SCALE;
import static sun.misc.Unsafe.ARRAY_INT_INDEX_SCALE;
import static sun.misc.Unsafe.ARRAY_LONG_INDEX_SCALE;
import static sun.misc.Unsafe.ARRAY_SHORT_INDEX_SCALE;
public class TestUncheckedByteArrays
{
private static final int POSITIONS_PER_PAGE = 10_000;
private TestUncheckedByteArrays()
{}
@Test
public static void testSetByte()
{
byte[] source = new byte[POSITIONS_PER_PAGE];
ThreadLocalRandom.current().nextBytes(source);
testSequential(Bytes.asList(source), ARRAY_BYTE_INDEX_SCALE, UncheckedByteArrays::setByteUnchecked, UncheckedByteArrays::getByteUnchecked);
testRandom(Bytes.asList(source), ARRAY_BYTE_INDEX_SCALE, UncheckedByteArrays::setByteUnchecked, UncheckedByteArrays::getByteUnchecked);
}
@Test
public static void testSetShort()
{
List<Short> source = IntStream.range(0, POSITIONS_PER_PAGE).mapToObj(i -> (short) ThreadLocalRandom.current().nextInt(256)).collect(Collectors.toList());
testSequential(source, ARRAY_SHORT_INDEX_SCALE, UncheckedByteArrays::setShortUnchecked, UncheckedByteArrays::getShortUnchecked);
testRandom(source, ARRAY_SHORT_INDEX_SCALE, UncheckedByteArrays::setShortUnchecked, UncheckedByteArrays::getShortUnchecked);
}
@Test
public static void testSetInt()
{
List<Integer> source = IntStream.range(0, POSITIONS_PER_PAGE).boxed().collect(Collectors.toList());
testSequential(source, ARRAY_INT_INDEX_SCALE, UncheckedByteArrays::setIntUnchecked, UncheckedByteArrays::getIntUnchecked);
testRandom(source, ARRAY_INT_INDEX_SCALE, UncheckedByteArrays::setIntUnchecked, UncheckedByteArrays::getIntUnchecked);
}
@Test
public static void testSetLong()
{
List<Long> source = LongStream.range(0, POSITIONS_PER_PAGE).boxed().collect(Collectors.toList());
testSequential(source, ARRAY_LONG_INDEX_SCALE, UncheckedByteArrays::setLongUnchecked, UncheckedByteArrays::getLongUnchecked);
testRandom(source, ARRAY_LONG_INDEX_SCALE, UncheckedByteArrays::setLongUnchecked, UncheckedByteArrays::getLongUnchecked);
}
private static <T> void testSequential(List<T> source, int elementSize, TriFunction<byte[], Integer, T> writeFunction, BiFunction<byte[], Integer, T> readFunction)
{
byte[] destination = new byte[source.size() * elementSize];
int index = 0;
for (T value : source) {
index = writeFunction.apply(destination, index, value);
}
assertEquals(index, POSITIONS_PER_PAGE * elementSize);
assertCopied(source, destination, elementSize, readFunction);
}
private static <T> void testRandom(List<T> source, int elementSize, TriFunction<byte[], Integer, T> writeFunction, BiFunction<byte[], Integer, T> readFunction)
{
byte[] destination = new byte[source.size() * elementSize];
List<T> expected = new ArrayList<>();
List<Integer> positions = IntStream.range(0, POSITIONS_PER_PAGE).boxed().collect(Collectors.toList());
Collections.shuffle(positions);
int index = 0;
for (int i = 0; i < POSITIONS_PER_PAGE; i++) {
int position = positions.get(i);
index = writeFunction.apply(destination, index, source.get(position));
expected.add(source.get(position));
}
assertEquals(index, POSITIONS_PER_PAGE * elementSize);
assertCopied(expected, destination, elementSize, readFunction);
}
private static <T> void assertCopied(List<T> expected, byte[] actual, int elementSize, BiFunction<byte[], Integer, T> readFunction)
{
for (int index = 0; index < expected.size(); index++) {
assertEquals(readFunction.apply(actual, index * elementSize), expected.get(index));
}
}
@FunctionalInterface
private interface TriFunction<T, U, S>
{
int apply(T t, U u, S s);
}
}