Github user hequn8128 commented on a diff in the pull request:
https://github.com/apache/flink/pull/5327#discussion_r184994503
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/runtime/join/NonWindowOuterJoin.scala
---
@@ -0,0 +1,303 @@
+/*
+ * 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.table.runtime.join
+
+import org.apache.flink.api.common.state._
+import org.apache.flink.api.common.typeinfo.TypeInformation
+import org.apache.flink.api.java.tuple.{Tuple2 => JTuple2}
+import org.apache.flink.configuration.Configuration
+import org.apache.flink.streaming.api.functions.co.CoProcessFunction
+import org.apache.flink.table.api.{StreamQueryConfig, Types}
+import org.apache.flink.table.runtime.types.CRow
+import org.apache.flink.types.Row
+import org.apache.flink.util.Collector
+
+/**
+ * Connect data for left stream and right stream. Base class for stream
non-window outer Join.
+ *
+ * @param leftType the input type of left stream
+ * @param rightType the input type of right stream
+ * @param resultType the output type of join
+ * @param genJoinFuncName the function code of other non-equi condition
+ * @param genJoinFuncCode the function name of other non-equi condition
+ * @param isLeftJoin the type of join, whether it is the type of
left join
+ * @param queryConfig the configuration for the query to generate
+ */
+abstract class NonWindowOuterJoin(
+ leftType: TypeInformation[Row],
+ rightType: TypeInformation[Row],
+ resultType: TypeInformation[CRow],
+ genJoinFuncName: String,
+ genJoinFuncCode: String,
+ isLeftJoin: Boolean,
+ queryConfig: StreamQueryConfig)
+ extends NonWindowJoin(
+ leftType,
+ rightType,
+ resultType,
+ genJoinFuncName,
+ genJoinFuncCode,
+ queryConfig) {
+
+ // result row, all fields from right will be null. Used for output when
there is no matched rows.
+ protected var leftResultRow: Row = _
+ // result row, all fields from left will be null. Used for output when
there is no matched rows.
+ protected var rightResultRow: Row = _
+ // how many matched rows from the right table for each left row. Index 0
is used for left
+ // stream, index 1 is used for right stream.
+ protected var joinCntState: Array[MapState[Row, Long]] = _
+
+ override def open(parameters: Configuration): Unit = {
+ super.open(parameters)
+
+ leftResultRow = new Row(resultType.getArity)
+ rightResultRow = new Row(resultType.getArity)
+
+ joinCntState = new Array[MapState[Row, Long]](2)
+ val leftJoinCntStateDescriptor = new MapStateDescriptor[Row, Long](
+ "leftJoinCnt", leftType,
Types.LONG.asInstanceOf[TypeInformation[Long]])
+ joinCntState(0) =
getRuntimeContext.getMapState(leftJoinCntStateDescriptor)
+ val rightJoinCntStateDescriptor = new MapStateDescriptor[Row, Long](
+ "rightJoinCnt", rightType,
Types.LONG.asInstanceOf[TypeInformation[Long]])
+ joinCntState(1) =
getRuntimeContext.getMapState(rightJoinCntStateDescriptor)
+
+ LOG.debug(s"Instantiating NonWindowOuterJoin")
+ }
+
+ /**
+ * Join current row with other side rows. Preserve current row if there
are no matched rows
+ * from other side.
+ */
+ def preservedJoin(
+ inputRow: Row,
+ inputRowFromLeft: Boolean,
+ otherSideState: MapState[Row, JTuple2[Long, Long]],
+ curProcessTime: Long): Long = {
+
+ val otherSideIterator = otherSideState.iterator()
+ while (otherSideIterator.hasNext) {
+ val otherSideEntry = otherSideIterator.next()
+ val otherSideRow = otherSideEntry.getKey
+ val otherSideCntAndExpiredTime = otherSideEntry.getValue
+ // join
+ cRowWrapper.setTimes(otherSideCntAndExpiredTime.f0)
+ callJoinFunction(inputRow, inputRowFromLeft, otherSideRow,
cRowWrapper)
+ // clear expired data. Note: clear after join to keep closer to the
original semantics
+ if (stateCleaningEnabled && curProcessTime >=
otherSideCntAndExpiredTime.f1) {
+ otherSideIterator.remove()
+ }
+ }
+ val joinCnt = cRowWrapper.getEmitCnt
+ // The result is NULL from the other side, if there is no match.
+ if (joinCnt == 0) {
+ cRowWrapper.setTimes(1)
+ collectAppendNull(inputRow, inputRowFromLeft, cRowWrapper)
+ }
+ joinCnt
+ }
+
+ /**
+ * Join current row with other side rows. Retract previous output row
if matched condition
+ * changed, i.e, matched condition is changed from matched to unmatched
or vice versa.
+ */
+ def retractJoin(
+ value: CRow,
+ inputRowFromLeft: Boolean,
+ currentSideState: MapState[Row, JTuple2[Long, Long]],
+ otherSideState: MapState[Row, JTuple2[Long, Long]],
+ curProcessTime: Long): Unit = {
+
+ val inputRow = value.row
+ val otherSideIterator = otherSideState.iterator()
+ // number of record in current side, here we only check whether number
equals to 0 or 1.
+ val recordNum: Long = recordNumInState(currentSideState)
+
+ while (otherSideIterator.hasNext) {
+ val otherSideEntry = otherSideIterator.next()
+ val otherSideRow = otherSideEntry.getKey
+ val otherSideCntAndExpiredTime = otherSideEntry.getValue
+ cRowWrapper.setTimes(otherSideCntAndExpiredTime.f0)
+
+ // retract previous preserved record append with null
+ if (recordNum == 1 && value.change) {
+ cRowWrapper.setChange(false)
+ collectAppendNull(otherSideRow, !inputRowFromLeft, cRowWrapper)
+ cRowWrapper.setChange(true)
+ }
+ // do normal join
+ callJoinFunction(inputRow, inputRowFromLeft, otherSideRow,
cRowWrapper)
+
+ // output preserved record append with null if have to
+ if (!value.change && recordNum == 0) {
+ cRowWrapper.setChange(true)
+ collectAppendNull(otherSideRow, !inputRowFromLeft, cRowWrapper)
+ cRowWrapper.setChange(false)
--- End diff --
There are no more cRowWrapper operations after this line and
`processElement` calls `cRowWrapper.setChange(value.change)` every new row
comes. I think we can remove this line.
---
