twalthr commented on a change in pull request #7177: [FLINK-7599] [table]
Support for aggregates in MATCH_RECOGNIZE
URL: https://github.com/apache/flink/pull/7177#discussion_r238718086
##########
File path:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/codegen/MatchCodeGenerator.scala
##########
@@ -445,4 +498,223 @@ class MatchCodeGenerator(
generateFieldAccess(patternVariableRef.copy(code = NO_CODE),
fieldRef.getIndex)
}
+
+ class AggBuilder(variable: String) {
+
+ private val aggregates = new mutable.ListBuffer[RexCall]()
+
+ private val variableUID = newName("variable")
+
+ private val resultRowTerm = newName(s"aggRow_$variableUID")
+
+ private val rowTypeTerm = "org.apache.flink.types.Row"
+
+ def getOrAddAggregation(call: RexCall): GeneratedExpression = {
+ reusableInputUnboxingExprs.get((call.toString, 0)) match {
+ case Some(expr) =>
+ expr
+
+ case None =>
+ val exp: GeneratedExpression = generateAggAccess(call)
+ aggregates += call
+ reusableInputUnboxingExprs((call.toString, 0)) = exp
+ exp.copy(code = NO_CODE)
+ }
+ }
+
+ private def generateAggAccess(call: RexCall) = {
+ val singleResultTerm = newName("result")
+ val singleResultNullTerm = newName("nullTerm")
+ val singleResultType = FlinkTypeFactory.toTypeInfo(call.`type`)
+ val singleResultTypeTerm = boxedTypeTermForTypeInfo(singleResultType)
+
+ val patternName = findEventsByPatternName(variable)
+
+ val codeForAgg =
+ j"""
+ |$rowTypeTerm $resultRowTerm =
calculateAgg_$variableUID(${patternName.resultTerm});
+ |""".stripMargin
+
+ reusablePerRecordStatements += codeForAgg
+
+ val defaultValue = primitiveDefaultValue(singleResultType)
+ val codeForSingleAgg =
+ j"""
+ |boolean $singleResultNullTerm;
+ |$singleResultTypeTerm $singleResultTerm = ($singleResultTypeTerm)
$resultRowTerm
+ | .getField(${aggregates.size});
+ |if ($singleResultTerm != null) {
+ | $singleResultNullTerm = false;
+ |} else {
+ | $singleResultNullTerm = true;
+ | $singleResultTerm = $defaultValue;
+ |}
+ |""".stripMargin
+
+ reusablePerRecordStatements += codeForSingleAgg
+
+ val exp = GeneratedExpression(singleResultTerm,
+ singleResultNullTerm,
+ NO_CODE,
+ singleResultType)
+ exp
+ }
+
+ def generateAggFunction() : Unit = {
+ val (aggs, exprs) = extractAggregatesAndExpressions
+
+ val aggGenerator = new AggregationCodeGenerator(config, false, input,
None)
+
+ val aggFunc = aggGenerator.generateAggregations(
+ s"AggFunction_$variableUID",
+ exprs.map(r => FlinkTypeFactory.toTypeInfo(r.getType)),
+ aggs.map(_.aggFunction).toArray,
+ aggs.map(_.inputIndices).toArray,
+ aggs.indices.toArray,
+ Array.fill(aggs.size)(false),
+ isStateBackedDataViews = false,
+ partialResults = false,
+ Array.emptyIntArray,
+ None,
+ aggs.size,
+ needRetract = false,
+ needMerge = false,
+ needReset = false,
+ None
+ )
+
+ reusableMemberStatements.add(aggFunc.code)
+
+ val transformFuncName = s"transformRowForAgg_$variableUID"
+ val inputTransform: String = generateAggInputExprEvaluation(
+ exprs,
+ transformFuncName)
+
+ generateAggCalculation(aggFunc, transformFuncName, inputTransform)
+ }
+
+ private case class MatchAggCall(
+ aggFunction: TableAggregateFunction[_, _],
+ inputIndices: Array[Int],
+ dataViews: Seq[DataViewSpec[_]]
+ )
+
+ private def extractAggregatesAndExpressions: (Seq[MatchAggCall],
Seq[RexNode]) = {
+ val inputRows = new mutable.LinkedHashMap[String, (RexNode, Int)]
+
+ val aggs = aggregates.map(rexAggCall => {
+ val callsWithIndices = rexAggCall.operands.asScala.map(innerCall => {
+ inputRows.get(innerCall.toString) match {
+ case Some(x) =>
+ x
+
+ case None =>
+ val callWithIndex = (innerCall, inputRows.size)
+ inputRows(innerCall.toString) = callWithIndex
+ callWithIndex
+ }
+ }).toList
+
+ val agg = rexAggCall.getOperator.asInstanceOf[SqlAggFunction]
+ (agg, callsWithIndices.map(_._1), callsWithIndices.map(_._2).toArray)
+ }).zipWithIndex.map {
+ case (agg, index) =>
+ val result = AggregateUtil
+ .transformToAggregateFunction(agg._1,
+ isDistinct = false,
+ agg._2.map(_.getType),
+ needRetraction = false,
+ config,
+ isStateBackedDataViews = false,
+ index)
+
+ MatchAggCall(result._1, agg._3, result._3)
+ }
+
+ (aggs, inputRows.values.map(_._1).toSeq)
+ }
+
+ private def generateAggCalculation(
+ aggFunc: GeneratedAggregationsFunction,
+ transformFuncName: String,
+ inputTransform: String)
+ : Unit = {
+ val aggregatorTerm = s"aggregator_$variableUID"
+ val code =
+ j"""
+ |private final ${aggFunc.name} $aggregatorTerm;
+ |
+ |$inputTransform
+ |
+ |private $rowTypeTerm calculateAgg_$variableUID(java.util.List
input)
+ | throws Exception {
+ | $rowTypeTerm accumulator = $aggregatorTerm.createAccumulators();
+ | for ($rowTypeTerm row : input) {
+ | $aggregatorTerm.accumulate(accumulator,
$transformFuncName(row));
+ | }
+ | $rowTypeTerm result = $aggregatorTerm.createOutputRow();
+ | $aggregatorTerm.setAggregationResults(accumulator, result);
+ | return result;
+ |}
+ """.stripMargin
+
+ reusableInitStatements.add(s"$aggregatorTerm = new ${aggFunc.name}();")
+ reusableOpenStatements.add(s"$aggregatorTerm.open(getRuntimeContext());")
+ reusableCloseStatements.add(s"$aggregatorTerm.close();")
+ reusableMemberStatements.add(code)
+ }
+
+ private def generateAggInputExprEvaluation(
+ inputExprs: Seq[RexNode],
+ funcName: String)
+ : String = {
+ innerAggExpr = true
+ val resultTerm = newName("result")
+ val exprs = inputExprs.zipWithIndex.map(row => {
+ val expr = generateExpression(row._1)
+ s"""
+ |${expr.code}
+ |if (${expr.nullTerm}) {
+ | $resultTerm.setField(${row._2}, null);
+ |} else {
+ | $resultTerm.setField(${row._2}, ${expr.resultTerm});
+ |}
+ """.stripMargin
+ }).mkString("\n")
+ innerAggExpr = false
+
+ j"""
+ |private $rowTypeTerm $funcName($rowTypeTerm $inputAggRowTerm) {
+ | $rowTypeTerm $resultTerm = new $rowTypeTerm(${inputExprs.size});
+ | $exprs
+ | return $resultTerm;
+ |}
+ """.stripMargin
+ }
+ }
+}
+
+class PatternVariableFinder extends RexDefaultVisitor[Option[String]] {
Review comment:
I think it is ok to duplicate this class. Because we are just talking about
25 lines. We should try to separate validation and translation. I know we are
also not doing it at other places but we should aim for it.
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