Github user fhueske commented on a diff in the pull request:
    --- Diff: 
    @@ -0,0 +1,33 @@
    + * 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
    + *
    + *
    + *
    + * 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.runtime.aggregate
    +  * Base class for reading a window property. The property will be 
extracted once and
    +  * can be read multiple times.
    +  */
    +trait PropertyRead[T] extends Serializable {
    +  def extract(window: Window): Unit
    --- End diff --
    I think we do not need a generic interface to extract properties. The 
`extract` method requires a window object but not all properties might be 
present in the window object. So I am not sure how much generalization is 
required here.
    I think we can implement a `TimeWindowPropertyCollector` that works as 
    class TimeWindowPropertyCollector(start: Int, end: Int) extends 
Collector[Row] {
      var finalCollector: Collector[Row] = _
      var timeWindow: TimeWindow = _
      override def collect(record: Row): Unit = {
        if (start > -1) {
          record.setField(start, timeWindow.getStart)
        if (end > -1) {
          record.setField(end, timeWindow.getEnd)
      override def close(): Unit = finalCollector.close()
    If we (ever) need more properties, we can add another wrapping collector or 
change the design. But at this point I think this is sufficient. 
    What do you think?

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 or file a JIRA ticket
with INFRA.

Reply via email to