content: /*
   * 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.beam.sdk.extensions.sorter;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.fail;
  import static org.mockito.ArgumentMatchers.any;
  import static org.mockito.Mockito.mock;
  import static org.mockito.Mockito.never;
  import static org.mockito.Mockito.times;
  import static org.mockito.Mockito.verify;
  import static org.mockito.Mockito.when;
  
  import java.io.IOException;
  import java.nio.file.FileVisitResult;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.nio.file.SimpleFileVisitor;
  import java.nio.file.attribute.BasicFileAttributes;
  import java.util.Arrays;
  import org.apache.beam.sdk.values.KV;
  import org.checkerframework.checker.nullness.qual.EnsuresNonNull;
  import org.checkerframework.checker.nullness.qual.Nullable;
  import org.junit.AfterClass;
  import org.junit.BeforeClass;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.rules.ExpectedException;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  
  /** Tests for {@link BufferedExternalSorter}. */
  @RunWith(JUnit4.class)
  @SuppressWarnings({
    "rawtypes" // TODO(https://github.com/apache/beam/issues/20447)
  })
  public class BufferedExternalSorterTest {
    @Rule public ExpectedException thrown = ExpectedException.none();
    private static @Nullable Path tmpLocation = null;
  
    public static Path getTmpLocation() {
      if (tmpLocation == null) {
        throw new IllegalStateException("getTmpLocation called outside of test context");
      }
      return tmpLocation;
    }
  
    @BeforeClass
    @EnsuresNonNull("tmpLocation")
    public static void setupTempDir() throws IOException {
      tmpLocation = Files.createTempDirectory("tmp");
    }
  
    @AfterClass
    public static void cleanupTempDir() throws IOException {
      Files.walkFileTree(
          getTmpLocation(),
          new SimpleFileVisitor<Path>() {
            @Override
            public FileVisitResult visitFile(Path file, BasicFileAttributes attrs)
                throws IOException {
              Files.delete(file);
              return FileVisitResult.CONTINUE;
            }
  
            @Override
            public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
              Files.delete(dir);
              return FileVisitResult.CONTINUE;
            }
          });
    }
  
    @SuppressWarnings("unchecked")
    @Test
    public void testNoFallback() throws Exception {
      ExternalSorter mockExternalSorter = mock(ExternalSorter.class);
      InMemorySorter mockInMemorySorter = mock(InMemorySorter.class);
      BufferedExternalSorter testSorter =
          new BufferedExternalSorter(mockExternalSorter, mockInMemorySorter);
  
      KV<byte[], byte[]>[] kvs =
          new KV[] {
            KV.of(new byte[] {0}, new byte[] {}),
            KV.of(new byte[] {0, 1}, new byte[] {}),
            KV.of(new byte[] {1}, new byte[] {})
          };
  
      when(mockInMemorySorter.addIfRoom(kvs[0])).thenReturn(true);
      when(mockInMemorySorter.addIfRoom(kvs[1])).thenReturn(true);
      when(mockInMemorySorter.addIfRoom(kvs[2])).thenReturn(true);
      when(mockInMemorySorter.sort()).thenReturn(Arrays.asList(kvs[0], kvs[1], kvs[2]));
  
      testSorter.add(kvs[0]);
      testSorter.add(kvs[1]);
      testSorter.add(kvs[2]);
  
      assertEquals(Arrays.asList(kvs[0], kvs[1], kvs[2]), testSorter.sort());
  
      // Verify external sorter was never called
      verify(mockExternalSorter, never()).add(any(KV.class));
      verify(mockExternalSorter, never()).sort();
    }
  
    @Test
    public void testFallback() throws Exception {
      ExternalSorter mockExternalSorter = mock(ExternalSorter.class);
      InMemorySorter mockInMemorySorter = mock(InMemorySorter.class);
      BufferedExternalSorter testSorter =
          new BufferedExternalSorter(mockExternalSorter, mockInMemorySorter);
  
      @SuppressWarnings("unchecked")
      KV<byte[], byte[]>[] kvs =
          new KV[] {
            KV.of(new byte[] {0}, new byte[] {}),
            KV.of(new byte[] {0, 1}, new byte[] {}),
            KV.of(new byte[] {1}, new byte[] {})
          };
  
      when(mockInMemorySorter.addIfRoom(kvs[0])).thenReturn(true);
      when(mockInMemorySorter.addIfRoom(kvs[1])).thenReturn(true);
      when(mockInMemorySorter.addIfRoom(kvs[2])).thenReturn(false);
      when(mockInMemorySorter.sort()).thenReturn(Arrays.asList(kvs[0], kvs[1]));
      when(mockExternalSorter.sort()).thenReturn(Arrays.asList(kvs[0], kvs[1], kvs[2]));
  
      testSorter.add(kvs[0]);
      testSorter.add(kvs[1]);
      testSorter.add(kvs[2]);
  
      assertEquals(Arrays.asList(kvs[0], kvs[1], kvs[2]), testSorter.sort());
  
      verify(mockExternalSorter, times(1)).add(kvs[0]);
      verify(mockExternalSorter, times(1)).add(kvs[1]);
      verify(mockExternalSorter, times(1)).add(kvs[2]);
    }
  
    @Test
    public void testEmpty() throws Exception {
      SorterTestUtils.testEmpty(
          BufferedExternalSorter.create(
              BufferedExternalSorter.options().withTempLocation(getTmpLocation().toString())));
    }
  
    @Test
    public void testSingleElement() throws Exception {
      SorterTestUtils.testSingleElement(
          BufferedExternalSorter.create(
              BufferedExternalSorter.options().withTempLocation(getTmpLocation().toString())));
    }
  
    @Test
    public void testEmptyKeyValueElement() throws Exception {
      SorterTestUtils.testEmptyKeyValueElement(
          BufferedExternalSorter.create(
              BufferedExternalSorter.options().withTempLocation(getTmpLocation().toString())));
    }
  
    @Test
    public void testMultipleIterations() throws Exception {
      SorterTestUtils.testMultipleIterations(
          BufferedExternalSorter.create(
              BufferedExternalSorter.options().withTempLocation(getTmpLocation().toString())));
    }
  
    @Test
    public void testManySortersFewRecords() throws Exception {
      SorterTestUtils.testRandom(
          () ->
              BufferedExternalSorter.create(
                  BufferedExternalSorter.options().withTempLocation(getTmpLocation().toString())),
          1000000,
          10);
    }
  
    @Test
    public void testOneSorterManyRecords() throws Exception {
      SorterTestUtils.testRandom(
          () ->
              BufferedExternalSorter.create(
                  BufferedExternalSorter.options().withTempLocation(getTmpLocation().toString())),
          1,
          1000000);
    }
  
    @Test
    public void testAddAfterSort() throws Exception {
      SorterTestUtils.testAddAfterSort(
          BufferedExternalSorter.create(
              BufferedExternalSorter.options().withTempLocation(getTmpLocation().toString())),
          thrown);
      fail();
    }
  
    @Test
    public void testSortTwice() throws Exception {
      SorterTestUtils.testSortTwice(
          BufferedExternalSorter.create(
              BufferedExternalSorter.options().withTempLocation(getTmpLocation().toString())),
          thrown);
      fail();
    }
  
    @Test
    public void testNegativeMemory() {
      thrown.expect(IllegalArgumentException.class);
      thrown.expectMessage("memoryMB must be greater than zero");
      BufferedExternalSorter.Options options =
          BufferedExternalSorter.options().withTempLocation(getTmpLocation().toString());
      options.withMemoryMB(-1);
    }
  
    @Test
    public void testZeroMemory() {
      thrown.expect(IllegalArgumentException.class);
      thrown.expectMessage("memoryMB must be greater than zero");
      BufferedExternalSorter.Options options = BufferedExternalSorter.options();
      options.withMemoryMB(0);
    }
  
    @Test
    public void testMemoryTooLarge() {
      thrown.expect(IllegalArgumentException.class);
      thrown.expectMessage("memoryMB must be less than 2048");
      BufferedExternalSorter.Options options = BufferedExternalSorter.options();
      options.withMemoryMB(2048);
    }
  }
  