NormalizedKeySorter implements InMemorySorter<T> { @Override public void swap(int i, int j) { final int bufferNumI = i / this.indexEntriesPerSegment; final int segmentOffsetI = (i % this.indexEntriesPerSegment) * this.indexEntrySize; final int bufferNumJ = j / this.indexEntriesPerSegment; final int segmentOffsetJ = (j % this.indexEntriesPerSegment) * this.indexEntrySize; final MemorySegment segI = this.sortIndex.get(bufferNumI); final MemorySegment segJ = this.sortIndex.get(bufferNumJ); segI.swapBytes(this.swapBuffer, segJ, segmentOffsetI, segmentOffsetJ, this.indexEntrySize); } NormalizedKeySorter(TypeSerializer<T> serializer, TypeComparator<T> comparator, List<MemorySegment> memory);  NormalizedKeySorter(TypeSerializer<T> serializer, TypeComparator<T> comparator, 
			List<MemorySegment> memory, int maxNormalizedKeyBytes); @Override void reset(); @Override boolean isEmpty(); @Override void dispose(); @Override long getCapacity(); @Override long getOccupancy(); @Override T getRecord(int logicalPosition); @Override T getRecord(T reuse, int logicalPosition); @Override boolean write(T record); @Override int compare(int i, int j); @Override void swap(int i, int j); @Override int size(); @Override final MutableObjectIterator<T> getIterator(); @Override void writeToOutput(ChannelWriterOutputView output); @Override void writeToOutput(ChannelWriterOutputView output, LargeRecordHandler<T> largeRecordsOutput); @Override void writeToOutput(final ChannelWriterOutputView output, final int start, int num);  }
@Test public void testSwap() throws Exception { final int numSegments = MEMORY_SIZE / MEMORY_PAGE_SIZE; final List<MemorySegment> memory = this.memoryManager.allocatePages(new DummyInvokable(), numSegments); NormalizedKeySorter<Tuple2<Integer, String>> sorter = newSortBuffer(memory); TestData.TupleGenerator generator = new TestData.TupleGenerator(SEED, KEY_MAX, VALUE_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH); Tuple2<Integer, String> record = new Tuple2<>(); int num = -1; do { generator.next(record); num++; } while (sorter.write(record)); int start = 0, end = num - 1; while (start < end) { sorter.swap(start++, end--); } generator.reset(); Tuple2<Integer, String> readTarget = new Tuple2<>(); int i = num - 1; while (i >= 0) { generator.next(record); readTarget = sorter.getRecord(readTarget, i--); int rk = readTarget.f0; int gk = record.f0; String rv = readTarget.f1; String gv = record.f1; Assert.assertEquals("The re-read key is wrong", gk, rk); Assert.assertEquals("The re-read value is wrong", gv, rv); } sorter.dispose(); this.memoryManager.release(memory); }