Github user fhueske commented on a diff in the pull request:
https://github.com/apache/flink/pull/4625#discussion_r140263201
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/runtime/join/TimeBoundedStreamInnerJoin.scala
---
@@ -0,0 +1,442 @@
+/*
+ * 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 java.util.{ArrayList, List => JList}
+
+import org.apache.flink.api.common.functions.FlatJoinFunction
+import org.apache.flink.api.common.state._
+import org.apache.flink.api.common.typeinfo.{BasicTypeInfo,
TypeInformation}
+import org.apache.flink.api.java.typeutils.ListTypeInfo
+import org.apache.flink.configuration.Configuration
+import org.apache.flink.streaming.api.functions.co.CoProcessFunction
+import org.apache.flink.table.codegen.Compiler
+import org.apache.flink.table.runtime.CRowWrappingCollector
+import
org.apache.flink.table.runtime.join.JoinTimeIndicator.JoinTimeIndicator
+import org.apache.flink.table.runtime.types.CRow
+import org.apache.flink.table.util.Logging
+import org.apache.flink.types.Row
+import org.apache.flink.util.Collector
+
+/**
+ * A CoProcessFunction to execute time-bounded stream inner-join.
+ * Two kinds of time criteria:
+ * "L.time between R.time + X and R.time + Y" or "R.time between L.time -
Y and L.time - X".
+ *
+ * @param leftLowerBound the lower bound for the left stream (X in the
criteria)
+ * @param leftUpperBound the upper bound for the left stream (Y in the
criteria)
+ * @param allowedLateness the lateness allowed for the two streams
+ * @param leftType the input type of left stream
+ * @param rightType the input type of right stream
+ * @param genJoinFuncName the function code of other non-equi conditions
+ * @param genJoinFuncCode the function name of other non-equi conditions
+ * @param timeIndicator indicate whether joining on proctime or rowtime
+ *
+ */
+abstract class TimeBoundedStreamInnerJoin(
+ private val leftLowerBound: Long,
+ private val leftUpperBound: Long,
+ private val allowedLateness: Long,
+ private val leftType: TypeInformation[Row],
+ private val rightType: TypeInformation[Row],
+ private val genJoinFuncName: String,
+ private val genJoinFuncCode: String,
+ private val leftTimeIdx: Int,
+ private val rightTimeIdx: Int,
+ private val timeIndicator: JoinTimeIndicator)
+ extends CoProcessFunction[CRow, CRow, CRow]
+ with Compiler[FlatJoinFunction[Row, Row, Row]]
+ with Logging {
+
+ private var cRowWrapper: CRowWrappingCollector = _
+
+ // the join function for other conditions
+ private var joinFunction: FlatJoinFunction[Row, Row, Row] = _
+
+ // cache to store rows from the left stream
+ private var leftCache: MapState[Long, JList[Row]] = _
+ // cache to store rows from the right stream
+ private var rightCache: MapState[Long, JList[Row]] = _
+
+ // state to record the timer on the left stream. 0 means no timer set
+ private var leftTimerState: ValueState[Long] = _
+ // state to record the timer on the right stream. 0 means no timer set
+ private var rightTimerState: ValueState[Long] = _
+
+ private val leftRelativeSize: Long = -leftLowerBound
+ private val rightRelativeSize: Long = leftUpperBound
+
+ protected var leftOperatorTime: Long = 0L
+ protected var rightOperatorTime: Long = 0L
+
+ //For delayed cleanup
+ private val cleanupDelay = (leftRelativeSize + rightRelativeSize) / 2
+
+ if (allowedLateness < 0) {
+ throw new IllegalArgumentException("The allowed lateness must be
non-negative.")
+ }
+
+ /**
+ * Get the maximum interval between receiving a row and emitting it (as
part of a joined result).
+ * Only reasonable for row time join.
+ *
+ * @return the maximum delay for the outputs
+ */
+ def getMaxOutputDelay: Long = Math.max(leftRelativeSize,
rightRelativeSize) + allowedLateness
+
+ override def open(config: Configuration) {
+ LOG.debug(s"Compiling JoinFunction: $genJoinFuncName \n\n " +
+ s"Code:\n$genJoinFuncCode")
+ val clazz = compile(
+ getRuntimeContext.getUserCodeClassLoader,
+ genJoinFuncName,
+ genJoinFuncCode)
+ LOG.debug("Instantiating JoinFunction.")
+ joinFunction = clazz.newInstance()
+
+ cRowWrapper = new CRowWrappingCollector()
+ cRowWrapper.setChange(true)
+
+ // Initialize the data caches.
+ val leftListTypeInfo: TypeInformation[JList[Row]] = new
ListTypeInfo[Row](leftType)
+ val leftStateDescriptor: MapStateDescriptor[Long, JList[Row]] =
+ new MapStateDescriptor[Long, JList[Row]](
+ timeIndicator + "InnerJoinLeftCache",
+ BasicTypeInfo.LONG_TYPE_INFO.asInstanceOf[TypeInformation[Long]],
+ leftListTypeInfo)
+ leftCache = getRuntimeContext.getMapState(leftStateDescriptor)
+
+ val rightListTypeInfo: TypeInformation[JList[Row]] = new
ListTypeInfo[Row](rightType)
+ val rightStateDescriptor: MapStateDescriptor[Long, JList[Row]] =
+ new MapStateDescriptor[Long, JList[Row]](
+ timeIndicator + "InnerJoinRightCache",
+ BasicTypeInfo.LONG_TYPE_INFO.asInstanceOf[TypeInformation[Long]],
+ rightListTypeInfo)
+ rightCache = getRuntimeContext.getMapState(rightStateDescriptor)
+
+ // Initialize the timer states.
+ val leftTimerStateDesc: ValueStateDescriptor[Long] =
+ new ValueStateDescriptor[Long](timeIndicator +
"InnerJoinLeftTimerState", classOf[Long])
+ leftTimerState = getRuntimeContext.getState(leftTimerStateDesc)
+
+ val rightTimerStateDesc: ValueStateDescriptor[Long] =
+ new ValueStateDescriptor[Long](timeIndicator +
"InnerJoinRightTimerState", classOf[Long])
+ rightTimerState = getRuntimeContext.getState(rightTimerStateDesc)
+ }
+
+ /**
+ * Process rows from the left stream.
+ */
+ override def processElement1(
+ cRowValue: CRow,
+ ctx: CoProcessFunction[CRow, CRow, CRow]#Context,
+ out: Collector[CRow]): Unit = {
+ updateOperatorTime(ctx)
+ val rowTime: Long = getTimeForLeftStream(ctx, cRowValue)
+ val oppositeLowerBound: Long = rowTime - rightRelativeSize
+ val oppositeUpperBound: Long = rowTime + leftRelativeSize
+ processElement(
+ cRowValue,
+ rowTime,
+ ctx,
+ out,
+ leftOperatorTime,
+ oppositeLowerBound,
+ oppositeUpperBound,
+ rightOperatorTime,
+ rightTimerState,
+ leftCache,
+ rightCache,
+ leftRow = true
+ )
+ }
+
+ /**
+ * Process rows from the right stream.
+ */
+ override def processElement2(
+ cRowValue: CRow,
+ ctx: CoProcessFunction[CRow, CRow, CRow]#Context,
+ out: Collector[CRow]): Unit = {
+ updateOperatorTime(ctx)
+ val rowTime: Long = getTimeForRightStream(ctx, cRowValue)
+ val oppositeLowerBound: Long = rowTime - leftRelativeSize
+ val oppositeUpperBound: Long = rowTime + rightRelativeSize
+ processElement(
+ cRowValue,
+ rowTime,
+ ctx,
+ out,
+ rightOperatorTime,
+ oppositeLowerBound,
+ oppositeUpperBound,
+ leftOperatorTime,
+ leftTimerState,
+ rightCache,
+ leftCache,
+ leftRow = false
+ )
+ }
+
+ /**
+ * Put a row from the input stream into the cache and iterate the
opposite cache to
+ * output join results meeting the conditions. If there is no timer set
for the OPPOSITE
+ * STREAM, register one.
+ */
+ private def processElement(
+ cRowValue: CRow,
+ timeForRow: Long,
+ ctx: CoProcessFunction[CRow, CRow, CRow]#Context,
+ out: Collector[CRow],
+ myWatermark: Long,
+ oppositeLowerBound: Long,
+ oppositeUpperBound: Long,
+ oppositeWatermark: Long,
+ oppositeTimeState: ValueState[Long],
+ rowListCache: MapState[Long, JList[Row]],
+ oppositeCache: MapState[Long, JList[Row]],
+ leftRow: Boolean): Unit = {
+ cRowWrapper.out = out
+ val row = cRowValue.row
+ if (!checkRowOutOfDate(timeForRow, myWatermark)) {
+ // Put the row into the cache for later use.
+ var rowList = rowListCache.get(timeForRow)
+ if (null == rowList) {
+ rowList = new ArrayList[Row](1)
+ }
+ rowList.add(row)
+ rowListCache.put(timeForRow, rowList)
--- End diff --
Ah, I misread your proposal then :-) I think starting from a constant value
is a good idea. When making it dynamic we have to be careful. Too high
granularity will lead to larger lists and higher ser/de overhead.
Btw. while iterating over the list of a rounded key, we can still clean-up
the state using the same condition as before and eagerly reduce the state size.
---
