Github user StefanRRichter commented on a diff in the pull request:
https://github.com/apache/flink/pull/6228#discussion_r199813529
--- Diff:
flink-runtime/src/main/java/org/apache/flink/runtime/state/heap/HeapPriorityQueue.java
---
@@ -0,0 +1,341 @@
+/*
+ * 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.runtime.state.heap;
+
+import org.apache.flink.runtime.state.InternalPriorityQueue;
+import org.apache.flink.util.CloseableIterator;
+
+import javax.annotation.Nonnegative;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Comparator;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+import static org.apache.flink.util.CollectionUtil.MAX_ARRAY_SIZE;
+
+/**
+ * Basic heap-based priority queue for {@link HeapPriorityQueueElement}
objects. This heap supports fast deletes
+ * because it manages position indexes of the contained {@link
HeapPriorityQueueElement}s. The heap implementation is
+ * a simple binary tree stored inside an array. Element indexes in the
heap array start at 1 instead of 0 to make array
+ * index computations a bit simpler in the hot methods. Object
identification of remove is based on object identity and
--- End diff --
ð
---
