/*
* Copyright 2015, 2016 Tagir Valeev
*
* 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 one.util.streamex;
import java.util.AbstractMap;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Map.Entry;
import java.util.Objects;
import java.util.Random;
import java.util.Spliterator;
import java.util.function.BiConsumer;
import java.util.function.Function;
import java.util.function.Supplier;
import java.util.stream.Stream;
import one.util.streamex.CollapseSpliterator;
import one.util.streamex.IntStreamEx;
import one.util.streamex.StreamEx;
import one.util.streamex.StreamExInternals;
import org.junit.Test;
import static one.util.streamex.TestHelpers.*;
import static org.junit.Assert.*;
/**
* @author Tagir Valeev
*
*/
public class CollapseSpliteratorTest {
private static <T> void splitEquals(Spliterator<T> source, BiConsumer<Spliterator<T>, Spliterator<T>> consumer) {
Spliterator<T> right = new CollapseSpliterator<>(Objects::equals, Function.identity(), StreamExInternals
.selectFirst(), StreamExInternals.selectFirst(), source);
Spliterator<T> left = right.trySplit();
assertNotNull(left);
consumer.accept(left, right);
}
@Test
public void testSimpleSplit() {
List<Integer> input = Arrays.asList(1, 1, 1, 2, 2, 2, 2, 2);
splitEquals(input.spliterator(), (left, right) -> {
List<Integer> result = new ArrayList<>();
left.forEachRemaining(result::add);
right.forEachRemaining(result::add);
assertEquals(Arrays.asList(1, 2), result);
});
splitEquals(input.spliterator(), (left, right) -> {
List<Integer> result = new ArrayList<>();
List<Integer> resultRight = new ArrayList<>();
right.forEachRemaining(resultRight::add);
left.forEachRemaining(result::add);
result.addAll(resultRight);
assertEquals(Arrays.asList(1, 2), result);
});
input = IntStreamEx.of(new Random(1), 100, 1, 10).sorted().boxed().toList();
splitEquals(input.spliterator(), (left, right) -> {
List<Integer> result = new ArrayList<>();
List<Integer> resultRight = new ArrayList<>();
for (int i = 0; i < 10; i++) {
left.tryAdvance(result::add);
right.tryAdvance(resultRight::add);
}
result.addAll(resultRight);
assertEquals(IntStreamEx.range(1, 10).boxed().toList(), result);
});
input = IntStreamEx.constant(100, 100).append(2).prepend(1).boxed().toList();
splitEquals(StreamEx.of(input).without(100).parallel().spliterator(), (left, right) -> {
List<Integer> result = new ArrayList<>();
left.forEachRemaining(result::add);
right.forEachRemaining(result::add);
assertEquals(Arrays.asList(1, 2), result);
});
input = Arrays.asList(0, 0, 1, 1, 1, 1, 4, 6, 6, 3, 3, 10);
splitEquals(Stream.concat(Stream.empty(), input.parallelStream()).spliterator(), (left, right) -> {
List<Integer> result = new ArrayList<>();
left.forEachRemaining(result::add);
right.forEachRemaining(result::add);
assertEquals(Arrays.asList(0, 1, 4, 6, 3, 10), result);
});
}
@Test
public void testNonIdentity() {
checkNonIdentity(Arrays.asList(1, 2, 5, 6, 7, 8, 10, 11, 15));
checkNonIdentity(IntStreamEx.range(3, 100).prepend(1).boxed().toList());
}
private void checkNonIdentity(List<Integer> input) {
checkSpliterator("collpase", () -> new CollapseSpliterator<Integer, Entry<Integer, Integer>>(
(a, b) -> (b - a == 1), a -> new AbstractMap.SimpleEntry<>(a, a),
(acc, a) -> new AbstractMap.SimpleEntry<>(acc.getKey(), a), (a, b) -> new AbstractMap.SimpleEntry<>(a
.getKey(), b.getValue()), input.spliterator()));
}
@Test
public void testMultiSplit() {
List<Integer> input = Arrays.asList(0, 0, 1, 1, 1, 1, 4, 6, 6, 3, 3, 10);
multiSplit(input::spliterator);
multiSplit(() -> Stream.concat(Stream.empty(), input.parallelStream()).spliterator());
}
private void multiSplit(Supplier<Spliterator<Integer>> inputSpliterator) throws AssertionError {
withRandom(r -> repeat(100, n -> {
Spliterator<Integer> spliterator = new CollapseSpliterator<>(Objects::equals, Function.identity(),
StreamExInternals.selectFirst(), StreamExInternals.selectFirst(), inputSpliterator.get());
List<Integer> result = new ArrayList<>();
List<Spliterator<Integer>> spliterators = new ArrayList<>();
spliterators.add(spliterator);
for (int i = 0; i < 8; i++) {
Spliterator<Integer> split = spliterators.get(r.nextInt(spliterators.size())).trySplit();
if (split != null)
spliterators.add(split);
}
Collections.shuffle(spliterators, r);
repeat(spliterators.size(), i -> spliterators.get(i-1).forEachRemaining(result::add));
assertEquals(6, result.size());
}));
}
}