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.spark.util.collection.unsafe.sort;
  
  import java.nio.charset.StandardCharsets;
  import java.util.Arrays;
  
  import org.junit.Assert;
  import org.junit.Test;
  
  import org.apache.spark.HashPartitioner;
  import org.apache.spark.SparkConf;
  import org.apache.spark.memory.TestMemoryConsumer;
  import org.apache.spark.memory.TestMemoryManager;
  import org.apache.spark.memory.TaskMemoryManager;
  import org.apache.spark.unsafe.Platform;
  import org.apache.spark.unsafe.memory.MemoryBlock;
  
  import static org.hamcrest.MatcherAssert.assertThat;
  import static org.hamcrest.Matchers.greaterThanOrEqualTo;
  import static org.hamcrest.Matchers.isIn;
  import static org.junit.Assert.assertEquals;
  import static org.mockito.Mockito.mock;
  
  public class UnsafeInMemorySorterSuite {
  
    protected boolean shouldUseRadixSort() { return false; }
  
    private static String getStringFromDataPage(Object baseObject, long baseOffset, int length) {
      final byte[] strBytes = new byte[length];
      Platform.copyMemory(baseObject, baseOffset, strBytes, Platform.BYTE_ARRAY_OFFSET, length);
      return new String(strBytes, StandardCharsets.UTF_8);
    }
  
    @Test
    public void testSortingEmptyInput() {
      final TaskMemoryManager memoryManager = new TaskMemoryManager(
        new TestMemoryManager(new SparkConf().set("spark.memory.offHeap.enabled", "false")), 0);
      final TestMemoryConsumer consumer = new TestMemoryConsumer(memoryManager);
      final UnsafeInMemorySorter sorter = new UnsafeInMemorySorter(consumer,
        memoryManager,
        mock(RecordComparator.class),
        mock(PrefixComparator.class),
        100,
        shouldUseRadixSort());
      final UnsafeSorterIterator iter = sorter.getSortedIterator();
      Assert.assertFalse(iter.hasNext());
    }
  
    @Test
    public void testSortingOnlyByIntegerPrefix() throws Exception {
      final String[] dataToSort = new String[] {
        "Boba",
        "Pearls",
        "Tapioca",
        "Taho",
        "Condensed Milk",
        "Jasmine",
        "Milk Tea",
        "Lychee",
        "Mango"
      };
      final TaskMemoryManager memoryManager = new TaskMemoryManager(
        new TestMemoryManager(new SparkConf().set("spark.memory.offHeap.enabled", "false")), 0);
      final TestMemoryConsumer consumer = new TestMemoryConsumer(memoryManager);
      final MemoryBlock dataPage = memoryManager.allocatePage(2048, consumer);
      final Object baseObject = dataPage.getBaseObject();
      // Write the records into the data page:
      long position = dataPage.getBaseOffset();
      for (String str : dataToSort) {
        final byte[] strBytes = str.getBytes(StandardCharsets.UTF_8);
        Platform.putInt(baseObject, position, strBytes.length);
        position += 4;
        Platform.copyMemory(
          strBytes, Platform.BYTE_ARRAY_OFFSET, baseObject, position, strBytes.length);
        position += strBytes.length;
      }
      // Since the key fits within the 8-byte prefix, we don't need to do any record comparison, so
      // use a dummy comparator
      final RecordComparator recordComparator = new RecordComparator() {
        @Override
        public int compare(
          Object leftBaseObject,
          long leftBaseOffset,
          Object rightBaseObject,
          long rightBaseOffset) {
          return 0;
        }
      };
      // Compute key prefixes based on the records' partition ids
      final HashPartitioner hashPartitioner = new HashPartitioner(4);
      // Use integer comparison for comparing prefixes (which are partition ids, in this case)
      final PrefixComparator prefixComparator = PrefixComparators.LONG;
      UnsafeInMemorySorter sorter = new UnsafeInMemorySorter(consumer, memoryManager,
        recordComparator, prefixComparator, dataToSort.length, shouldUseRadixSort());
      // Given a page of records, insert those records into the sorter one-by-one:
      position = dataPage.getBaseOffset();
      for (int i = 0; i < dataToSort.length; i++) {
        if (!sorter.hasSpaceForAnotherRecord()) {
          sorter.expandPointerArray(
            consumer.allocateArray(sorter.getMemoryUsage() / 8 * 2));
        }
        // position now points to the start of a record (which holds its length).
        final int recordLength = Platform.getInt(baseObject, position);
        final long address = memoryManager.encodePageNumberAndOffset(dataPage, position);
        final String str = getStringFromDataPage(baseObject, position + 4, recordLength);
        final int partitionId = hashPartitioner.getPartition(str);
        sorter.insertRecord(address, partitionId, false);
        position += 4 + recordLength;
      }
      final UnsafeSorterIterator iter = sorter.getSortedIterator();
      int iterLength = 0;
      long prevPrefix = -1;
      Arrays.sort(dataToSort);
      while (iter.hasNext()) {
        iter.loadNext();
        final String str =
          getStringFromDataPage(iter.getBaseObject(), iter.getBaseOffset(), iter.getRecordLength());
        final long keyPrefix = iter.getKeyPrefix();
        assertThat(str, isIn(Arrays.asList(dataToSort)));
        assertThat(keyPrefix, greaterThanOrEqualTo(prevPrefix));
        prevPrefix = keyPrefix;
        iterLength++;
      }
      assertEquals(dataToSort.length, iterLength);
    }
  }
  