Github user fhueske commented on a diff in the pull request:
https://github.com/apache/flink/pull/3715#discussion_r123026855
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/runtime/join/JoinUtil.scala
---
@@ -0,0 +1,385 @@
+/*
+ * 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.math.{BigDecimal => JBigDecimal}
+import java.util
+
+import org.apache.calcite.plan.RelOptUtil
+import org.apache.calcite.rel.`type`.RelDataType
+import org.apache.calcite.rel.core.JoinRelType
+import org.apache.calcite.rex._
+import org.apache.calcite.sql.SqlKind
+import org.apache.calcite.sql.fun.{SqlFloorFunction, SqlStdOperatorTable}
+import org.apache.flink.api.common.functions.FlatJoinFunction
+import org.apache.flink.api.common.typeinfo.TypeInformation
+import org.apache.flink.table.api.{TableConfig, TableException}
+import org.apache.flink.table.calcite.FlinkTypeFactory
+import org.apache.flink.table.codegen.{CodeGenerator, ExpressionReducer}
+import org.apache.flink.table.functions.TimeMaterializationSqlFunction
+import org.apache.flink.table.plan.schema.{RowSchema,
TimeIndicatorRelDataType}
+import org.apache.flink.types.Row
+
+import scala.collection.JavaConversions._
+
+/**
+ * An util class to help analyze and build join code .
+ */
+object JoinUtil {
+
+ /**
+ * check if the join case is stream join stream
+ *
+ * @param condition other condtion include time-condition
+ * @param inputType left and right connect stream type
+ */
+ private[flink] def isStreamStreamJoin(
+ condition: RexNode,
+ inputType: RelDataType) = {
+
+ def isExistTumble(expr: RexNode): Boolean = {
+ expr match {
+ case c: RexCall =>
+ c.getOperator match {
+ case _: SqlFloorFunction =>
+ c.getOperands.map(analyzeSingleConditionTerm(_, 0,
inputType)).exists(_.size > 0)
+ case SqlStdOperatorTable.TUMBLE =>
+ c.getOperands.map(analyzeSingleConditionTerm(_, 0,
inputType)).exists(_.size > 0)
+ case _ =>
+ c.getOperands.map(isExistTumble(_)).exists(_ == true)
+ }
+ case _ => false
+ }
+ }
+
+ val isExistTimeIndicator = analyzeSingleConditionTerm(condition, 0,
inputType).size > 0
+ val isExistTumbleExpr = isExistTumble(condition)
+
+ !isExistTumbleExpr && isExistTimeIndicator
+ }
+
+ /**
+ * Analyze time-condtion to get time boundary for each stream and get
the time type
+ * and return remain condition.
+ *
+ * @param condition other condtion include time-condition
+ * @param leftLogicalFieldCnt left stream logical field num
+ * @param leftPhysicalFieldCnt left stream physical field num
+ * @param inputType left and right connect stream type
+ * @param rexBuilder util to build rexNode
+ * @param config table environment config
+ */
+ private[flink] def analyzeTimeBoundary(
+ condition: RexNode,
+ leftLogicalFieldCnt: Int,
+ leftPhysicalFieldCnt: Int,
+ inputType: RelDataType,
+ rexBuilder: RexBuilder,
+ config: TableConfig): (RelDataType, Long, Long, Option[RexNode]) = {
+
+ // Converts the condition to conjunctive normal form (CNF)
+ val cnfCondition = RexUtil.toCnf(rexBuilder, condition)
+
+ // split the condition into time indicator condition and other
condition
+ val (timeTerms, remainTerms) =
+ splitJoinCondition(
+ cnfCondition,
+ leftLogicalFieldCnt,
+ inputType
+ )
+
+ if (timeTerms.size != 2) {
+ throw new TableException("There only can and must have 2 time
conditions.")
+ }
+
+ // extract time offset from the time indicator conditon
+ val streamTimeOffsets =
+ timeTerms.map(x => extractTimeOffsetFromCondition(x._3, x._2,
rexBuilder, config))
+
+ val (leftTableOffset, rightTableOffset) =
+ streamTimeOffsets match {
+ case Seq((x, true), (y, false)) => (x, y)
+ case Seq((x, false), (y, true)) => (y, x)
+ case _ =>
+ throw new TableException("Both input need time boundary.")
+ }
+
+ // compose the remain condition list into one condition
+ val remainCondition =
+ remainTerms match {
+ case Seq() => None
+ case _ =>
+ // turn the logical field index to physical field index
+ def transInputRef(expr: RexNode): RexNode = {
+ expr match {
+ case c: RexCall =>
+ val newOps = c.operands.map(transInputRef(_))
+ rexBuilder.makeCall(c.getType, c.getOperator, newOps)
+ case i: RexInputRef if i.getIndex >= leftLogicalFieldCnt =>
+ rexBuilder.makeInputRef(
+ i.getType,
+ i.getIndex - leftLogicalFieldCnt + leftPhysicalFieldCnt)
+ case _ => expr
+ }
+ }
+
+ Some(remainTerms.map(transInputRef(_)).reduceLeft( (l, r) => {
+ RelOptUtil.andJoinFilters(rexBuilder, l, r)
+ }))
+ }
+
+ (timeTerms.get(0)._1, leftTableOffset, rightTableOffset,
remainCondition)
+ }
+
+ /**
+ * Split the join conditions into time condition and non-time condition
+ */
+ private def splitJoinCondition(
+ cnfCondition: RexNode,
+ leftFieldCount: Int,
+ inputType: RelDataType): (Seq[(RelDataType, Boolean, RexNode)],
Seq[RexNode]) = {
+
+ cnfCondition match {
+ case c: RexCall if c.getKind == SqlKind.AND =>
+ val timeIndicators =
+ c.operands.map(splitJoinCondition(_, leftFieldCount, inputType))
+ timeIndicators.reduceLeft { (l, r) =>
+ (l._1 ++ r._1, l._2 ++ r._2)
+ }
+ case c: RexCall =>
+ val timeIndicators = analyzeSingleConditionTerm(c, leftFieldCount,
inputType)
+ timeIndicators match {
+ case Seq() =>
+ (Seq(), Seq(c))
+ case Seq(v1, v2) =>
+ if (v1._1 != v2._1) {
+ throw new TableException("The time indicators for each input
should be the same.")
+ }
+ if (v1._2 == v2._2) {
+ throw new TableException("Both input's time indicators is
needed.")
+ }
+ (Seq((v1._1, v1._2, c)), Seq())
+ case _ =>
+ throw new TableException(
+ "There only can and must have one time indicators for each
input.")
+ }
+ case other =>
+ val timeIndicators = analyzeSingleConditionTerm(other,
leftFieldCount, inputType)
+ timeIndicators match {
+ case Seq() =>
+ (Seq(), Seq(other))
+ case _ =>
+ throw new TableException("Time indicators can not be used in
non time-condition.")
+ }
+ }
+ }
+
+ /**
+ * analysis if condition term has time indicator
+ */
+ def analyzeSingleConditionTerm(
+ expression: RexNode,
+ leftFieldCount: Int,
+ inputType: RelDataType): Seq[(RelDataType, Boolean)] = {
+
+ expression match {
+ case i: RexInputRef =>
+ val idx = i.getIndex
+ inputType.getFieldList.get(idx).getType match {
+ case t: TimeIndicatorRelDataType if idx < leftFieldCount =>
+ // left table time indicator
+ Seq((t, true))
+ case t: TimeIndicatorRelDataType =>
+ // right table time indicator
+ Seq((t, false))
+ case _ => Seq()
+ }
+ case c: RexCall =>
+ c.operands.map(analyzeSingleConditionTerm(_, leftFieldCount,
inputType)).reduce(_++_)
+ case _ => Seq()
+ }
+ }
+
+ /**
+ * Extract time offset and determain which table the offset belong to
+ */
+ def extractTimeOffsetFromCondition(
+ timeTerm: RexNode,
+ isLeftExprBelongLeftTable: Boolean,
+ rexBuilder: RexBuilder,
+ config: TableConfig) = {
+
+ val timeCall: RexCall = timeTerm.asInstanceOf[RexCall]
+ val leftLiteral =
+ reduceTimeExpression(
+ timeCall.operands.get(0),
+ rexBuilder,
+ config)
+
+ val rightLiteral =
+ reduceTimeExpression(
+ timeCall.operands.get(1),
+ rexBuilder,
+ config)
+
+ val (tmpTimeOffset: Long, isLeftTableTimeOffset: Boolean) =
+ timeTerm.getKind match {
+ // e.g a.proctime > b.proctime - 5 sec, we need to store stream a.
+ // the left expr(a) belong to left table, so the offset belong to
left table
+ case kind @ (SqlKind.GREATER_THAN | SqlKind.GREATER_THAN_OR_EQUAL)
=>
+ (rightLiteral - leftLiteral, isLeftExprBelongLeftTable)
+ // e.g a.proctime < b.proctime + 5 sec, we need to store stream b.
+ case kind @ (SqlKind.LESS_THAN | SqlKind.LESS_THAN_OR_EQUAL) =>
+ (leftLiteral - rightLiteral, !isLeftExprBelongLeftTable)
+ case _ => 0
+ }
+
+ val timeOffset =
+ // only preceding offset need to store records
+ if (tmpTimeOffset < 0)
+ // determain the boudary value
+ if (timeTerm.getKind == SqlKind.LESS_THAN || timeTerm.getKind ==
SqlKind.GREATER_THAN) {
+ -tmpTimeOffset - 1
+ } else {
+ -tmpTimeOffset
+ }
+ else 0
+
+ (timeOffset, isLeftTableTimeOffset)
+ }
+
+ /**
+ * Calcute the time boundary. Replace the rowtime/proctime with zero
literal.
+ * For example:
+ * a.proctime - inteval '1' second > b.proctime - interval '1' second
- interval '2' second
--- End diff --
Update example? The method is used to reduce one side of a condition.
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