1 files changed, 124 insertions, 0 deletions
diff --git a/core/src/main/java/org/apache/spark/shuffle/unsafe/UnsafeShuffleInMemorySorter.java b/core/src/main/java/org/apache/spark/shuffle/unsafe/UnsafeShuffleInMemorySorter.java
new file mode 100644
index 0000000000..5bab501da9
--- /dev/null
+++ b/core/src/main/java/org/apache/spark/shuffle/unsafe/UnsafeShuffleInMemorySorter.java
@@ -0,0 +1,124 @@
+/*
+ * 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.shuffle.unsafe;
+
+import java.util.Comparator;
+
+import org.apache.spark.util.collection.Sorter;
+
+final class UnsafeShuffleInMemorySorter {
+
+  private final Sorter<PackedRecordPointer, long[]> sorter;
+  private static final class SortComparator implements Comparator<PackedRecordPointer> {
+    @Override
+    public int compare(PackedRecordPointer left, PackedRecordPointer right) {
+      return left.getPartitionId() - right.getPartitionId();
+    }
+  }
+  private static final SortComparator SORT_COMPARATOR = new SortComparator();
+
+  /**
+   * An array of record pointers and partition ids that have been encoded by
+   * {@link PackedRecordPointer}. The sort operates on this array instead of directly manipulating
+   * records.
+   */
+  private long[] pointerArray;
+
+  /**
+   * The position in the pointer array where new records can be inserted.
+   */
+  private int pointerArrayInsertPosition = 0;
+
+  public UnsafeShuffleInMemorySorter(int initialSize) {
+    assert (initialSize > 0);
+    this.pointerArray = new long[initialSize];
+    this.sorter = new Sorter<PackedRecordPointer, long[]>(UnsafeShuffleSortDataFormat.INSTANCE);
+  }
+
+  public void expandPointerArray() {
+    final long[] oldArray = pointerArray;
+    // Guard against overflow:
+    final int newLength = oldArray.length * 2 > 0 ? (oldArray.length * 2) : Integer.MAX_VALUE;
+    pointerArray = new long[newLength];
+    System.arraycopy(oldArray, 0, pointerArray, 0, oldArray.length);
+  }
+
+  public boolean hasSpaceForAnotherRecord() {
+    return pointerArrayInsertPosition + 1 < pointerArray.length;
+  }
+
+  public long getMemoryUsage() {
+    return pointerArray.length * 8L;
+  }
+
+  /**
+   * Inserts a record to be sorted.
+   *
+   * @param recordPointer a pointer to the record, encoded by the task memory manager. Due to
+   *                      certain pointer compression techniques used by the sorter, the sort can
+   *                      only operate on pointers that point to locations in the first
+   *                      {@link PackedRecordPointer#MAXIMUM_PAGE_SIZE_BYTES} bytes of a data page.
+   * @param partitionId the partition id, which must be less than or equal to
+   *                    {@link PackedRecordPointer#MAXIMUM_PARTITION_ID}.
+   */
+  public void insertRecord(long recordPointer, int partitionId) {
+    if (!hasSpaceForAnotherRecord()) {
+      if (pointerArray.length == Integer.MAX_VALUE) {
+        throw new IllegalStateException("Sort pointer array has reached maximum size");
+      } else {
+        expandPointerArray();
+      }
+    }
+    pointerArray[pointerArrayInsertPosition] =
+        PackedRecordPointer.packPointer(recordPointer, partitionId);
+    pointerArrayInsertPosition++;
+  }
+
+  /**
+   * An iterator-like class that's used instead of Java's Iterator in order to facilitate inlining.
+   */
+  public static final class UnsafeShuffleSorterIterator {
+
+    private final long[] pointerArray;
+    private final int numRecords;
+    final PackedRecordPointer packedRecordPointer = new PackedRecordPointer();
+    private int position = 0;
+
+    public UnsafeShuffleSorterIterator(int numRecords, long[] pointerArray) {
+      this.numRecords = numRecords;
+      this.pointerArray = pointerArray;
+    }
+
+    public boolean hasNext() {
+      return position < numRecords;
+    }
+
+    public void loadNext() {
+      packedRecordPointer.set(pointerArray[position]);
+      position++;
+    }
+  }
+
+  /**
+   * Return an iterator over record pointers in sorted order.
+   */
+  public UnsafeShuffleSorterIterator getSortedIterator() {
+    sorter.sort(pointerArray, 0, pointerArrayInsertPosition, SORT_COMPARATOR);
+    return new UnsafeShuffleSorterIterator(pointerArrayInsertPosition, pointerArray);
+  }
+}