Github user davies commented on a diff in the pull request:
https://github.com/apache/spark/pull/6444#discussion_r33526988
--- Diff:
sql/catalyst/src/main/java/org/apache/spark/sql/execution/UnsafeExternalRowSorter.java
---
@@ -0,0 +1,171 @@
+/*
+ * 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.sql.execution;
+
+import java.io.IOException;
+import java.util.Arrays;
+
+import scala.Function1;
+import scala.collection.Iterator;
+import scala.math.Ordering;
+
+import org.apache.spark.SparkEnv;
+import org.apache.spark.TaskContext;
+import org.apache.spark.sql.AbstractScalaRowIterator;
+import org.apache.spark.sql.catalyst.InternalRow;
+import org.apache.spark.sql.catalyst.expressions.UnsafeRow;
+import org.apache.spark.sql.catalyst.expressions.UnsafeRowConverter;
+import org.apache.spark.sql.types.StructType;
+import org.apache.spark.unsafe.PlatformDependent;
+import org.apache.spark.util.collection.unsafe.sort.PrefixComparator;
+import org.apache.spark.util.collection.unsafe.sort.RecordComparator;
+import org.apache.spark.util.collection.unsafe.sort.UnsafeExternalSorter;
+import org.apache.spark.util.collection.unsafe.sort.UnsafeSorterIterator;
+
+final class UnsafeExternalRowSorter {
+
+ private final StructType schema;
+ private final UnsafeRowConverter rowConverter;
+ private final RowComparator rowComparator;
+ private final PrefixComparator prefixComparator;
+ private final Function1<InternalRow, Long> prefixComputer;
+
+ public UnsafeExternalRowSorter(
+ StructType schema,
+ Ordering<InternalRow> ordering,
+ PrefixComparator prefixComparator,
+ // TODO: if possible, avoid this boxing of the return value
+ Function1<InternalRow, Long> prefixComputer) {
+ this.schema = schema;
+ this.rowConverter = new UnsafeRowConverter(schema);
+ this.rowComparator = new RowComparator(ordering, schema);
+ this.prefixComparator = prefixComparator;
+ this.prefixComputer = prefixComputer;
+ }
+
+ public Iterator<InternalRow> sort(Iterator<InternalRow> inputIterator)
throws IOException {
+ final SparkEnv sparkEnv = SparkEnv.get();
+ final TaskContext taskContext = TaskContext.get();
+ byte[] rowConversionBuffer = new byte[1024 * 8];
+ final UnsafeExternalSorter sorter = new UnsafeExternalSorter(
+ taskContext.taskMemoryManager(),
+ sparkEnv.shuffleMemoryManager(),
+ sparkEnv.blockManager(),
+ taskContext,
+ rowComparator,
+ prefixComparator,
+ 4096,
+ sparkEnv.conf()
+ );
+ try {
+ while (inputIterator.hasNext()) {
+ final InternalRow row = inputIterator.next();
+ final int sizeRequirement = rowConverter.getSizeRequirement(row);
+ if (sizeRequirement > rowConversionBuffer.length) {
+ rowConversionBuffer = new byte[sizeRequirement];
+ } else {
+ // Zero out the buffer that's used to hold the current row. This
is necessary in order
+ // to ensure that rows hash properly, since garbage data from
the previous row could
+ // otherwise end up as padding in this row. As a performance
optimization, we only zero
+ // out the portion of the buffer that we'll actually write to.
+ Arrays.fill(rowConversionBuffer, 0, sizeRequirement, (byte) 0);
+ }
+ final int bytesWritten =
+ rowConverter.writeRow(row, rowConversionBuffer,
PlatformDependent.BYTE_ARRAY_OFFSET);
+ assert (bytesWritten == sizeRequirement);
+ final long prefix = prefixComputer.apply(row);
+ sorter.insertRecord(
+ rowConversionBuffer,
+ PlatformDependent.BYTE_ARRAY_OFFSET,
+ sizeRequirement,
+ prefix
+ );
+ }
+ final UnsafeSorterIterator sortedIterator =
sorter.getSortedIterator();
+ return new AbstractScalaRowIterator() {
+
+ private final int numFields = schema.length();
+ private final UnsafeRow row = new UnsafeRow();
+
+ @Override
+ public boolean hasNext() {
+ return sortedIterator.hasNext();
+ }
+
+ @Override
+ public InternalRow next() {
+ try {
+ sortedIterator.loadNext();
+ if (hasNext()) {
+ row.pointTo(
+ sortedIterator.getBaseObject(),
sortedIterator.getBaseOffset(), numFields, schema);
+ return row;
+ } else {
+ final byte[] rowDataCopy = new
byte[sortedIterator.getRecordLength()];
+ PlatformDependent.copyMemory(
+ sortedIterator.getBaseObject(),
+ sortedIterator.getBaseOffset(),
+ rowDataCopy,
+ PlatformDependent.BYTE_ARRAY_OFFSET,
+ sortedIterator.getRecordLength()
+ );
+ row.backingArray = rowDataCopy;
+ row.pointTo(rowDataCopy,
PlatformDependent.BYTE_ARRAY_OFFSET, numFields, schema);
+ sorter.freeMemory();
+ return row;
+ }
+ } catch (IOException e) {
+ // TODO: we need to ensure that files are cleaned properly
after an exception,
+ // so we need better cleanup methods than freeMemory().
+ sorter.freeMemory();
+ // Scala iterators don't declare any checked exceptions, so we
need to use this hack
+ // to re-throw the exception:
+ PlatformDependent.throwException(e);
+ }
+ throw new RuntimeException("Exception should have been re-thrown
in next()");
+ };
+ };
+ } catch (IOException e) {
+ // TODO: we need to ensure that files are cleaned properly after an
exception,
+ // so we need better cleanup methods than freeMemory().
+ sorter.freeMemory();
+ throw e;
+ }
+ }
+
+ private static final class RowComparator extends RecordComparator {
+ private final StructType schema;
--- End diff --
Schema is not used in UnsafeRow now.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
