Github user twalthr commented on a diff in the pull request:
https://github.com/apache/flink/pull/1465#discussion_r47911141
--- Diff:
flink-staging/flink-table/src/main/scala/org/apache/flink/api/table/typeinfo/RowComparator.scala
---
@@ -0,0 +1,468 @@
+/*
+ * 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.flink.api.table.typeinfo
+
+import java.util
+
+import org.apache.flink.api.common.typeutils.base.BasicTypeComparator
+import org.apache.flink.api.common.typeutils.{CompositeTypeComparator,
TypeComparator, TypeSerializer}
+import org.apache.flink.api.java.typeutils.runtime.TupleComparatorBase
+import org.apache.flink.api.table.Row
+import org.apache.flink.api.table.typeinfo.NullMaskUtils.readIntoNullMask
+import org.apache.flink.api.table.typeinfo.RowComparator.NullChecker
+import org.apache.flink.core.memory.{MemorySegment, DataOutputView,
DataInputView}
+import org.apache.flink.types.{KeyFieldOutOfBoundsException,
NullKeyFieldException}
+
+/**
+ * Comparator for [[Row]].
+ */
+class RowComparator private (
+ /** key positions describe which fields are keys in what order */
+ val keyPositions: Array[Int],
+ /** comparators for the key fields, in the same order as the key
fields */
+ val comparators: Array[TypeComparator[_]],
+ /** serializers to deserialize the first n fields for comparison */
+ val serializers: Array[TypeSerializer[_]],
+ /** auxiliary fields for normalized key support */
+ private var normalizedKeyLengths: Array[Int],
+ private var numLeadingNormalizableKeys: Int,
+ private var normalizableKeyPrefixLen: Int,
+ private var invertNormKey: Boolean)
+ extends CompositeTypeComparator[Row] with Serializable {
+
+ // null masks for serialized comparison
+ private val nullMask1 = new Array[Boolean](serializers.length)
+ private val nullMask2 = new Array[Boolean](serializers.length)
+
+ // cache for the deserialized key field objects
+ @transient
+ private var deserializedKeyFields1: Array[Any] = null
+ @transient
+ private var deserializedKeyFields2: Array[Any] = null
+
+ // null checker for reference comparison
+ private val nullChecker = new NullChecker()
+
+ def this(
+ keyPositions: Array[Int],
+ comparators: Array[TypeComparator[_]],
+ serializers: Array[TypeSerializer[_]]) = {
+ this(keyPositions, comparators, serializers, new
Array[Int](keyPositions.length), 0, 0, false)
+ // set up auxiliary fields for normalized key support
+ setupAuxiliaryFields()
+ }
+
+ private def setupAuxiliaryFields(): Unit = {
+ var i = 0
+ while (i < keyPositions.length) {
+ val k: TypeComparator[_] = comparators(i)
+ // as long as the leading keys support normalized keys, we can build
up the composite key
+ if (k.supportsNormalizedKey()) {
+ if (i == 0) {
+ // the first comparator decides whether we need to invert the
key direction
+ invertNormKey = k.invertNormalizedKey()
+ }
+ else if (k.invertNormalizedKey() != invertNormKey) {
+ // if a successor does not agree on the inversion direction, it
cannot be part of the
+ // normalized key
+ return
+ }
+ numLeadingNormalizableKeys += 1
+ val len: Int = k.getNormalizeKeyLen
+ if (len < 0) {
+ throw new RuntimeException("Comparator " + k.getClass.getName +
+ " specifies an invalid length for the normalized key: " + len)
+ }
+ normalizedKeyLengths(i) = len + 1 // add one for a null byte
+ normalizableKeyPrefixLen += len + 1 // add one for a null byte
+ if (normalizableKeyPrefixLen < 0) {
+ // overflow, which means we are out of budget for normalized key
space anyways
+ normalizableKeyPrefixLen = Integer.MAX_VALUE
+ return
+ }
+ }
+ else {
+ return
+ }
+ i += 1
+ }
+ }
--- End diff --
Yes you are right. I just tried to be as close as possible to
TupleComparatorBase to prevent bugs. IMHO I think my implementation is more
readable as it similar to other classes (e.g.
https://github.com/dataArtisans/cascading-flink/blob/master/src/main/java/com/dataartisans/flink/cascading/types/tuple/DefinedTupleComparator.java).
But if other people think that your solution is better, I will change it.
---
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 infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---
