maropu commented on a change in pull request #20965: [SPARK-21870][SQL] Split aggregation code into small functions URL: https://github.com/apache/spark/pull/20965#discussion_r320557819
########## File path: sql/core/src/main/scala/org/apache/spark/sql/execution/aggregate/HashAggregateExec.scala ########## @@ -824,59 +944,158 @@ case class HashAggregateExec( // generating input columns, we use `currentVars`. ctx.currentVars = new Array[ExprCode](aggregateBufferAttributes.length) ++ input + val aggNames = aggregateExpressions.map(_.aggregateFunction.prettyName) + // Computes start offsets for each aggregation function code + // in the underlying buffer row. + val bufferStartOffsets = { + val offsets = mutable.ArrayBuffer[Int]() + var curOffset = 0 + updateExprs.foreach { exprsForOneFunc => + offsets += curOffset + curOffset += exprsForOneFunc.length + } + offsets.toArray + } + val updateRowInRegularHashMap: String = { ctx.INPUT_ROW = unsafeRowBuffer - val boundUpdateExpr = bindReferences(updateExpr, inputAttr) - val subExprs = ctx.subexpressionEliminationForWholeStageCodegen(boundUpdateExpr) + val boundUpdateExprs = updateExprs.map { updateExprsForOneFunc => + bindReferences(updateExprsForOneFunc, inputAttr) + } + val subExprs = ctx.subexpressionEliminationForWholeStageCodegen(boundUpdateExprs.flatten) val effectiveCodes = subExprs.codes.mkString("\n") - val unsafeRowBufferEvals = ctx.withSubExprEliminationExprs(subExprs.states) { - boundUpdateExpr.map(_.genCode(ctx)) + val unsafeRowBufferEvals = boundUpdateExprs.map { boundUpdateExprsForOneFunc => + ctx.withSubExprEliminationExprs(subExprs.states) { + boundUpdateExprsForOneFunc.map(_.genCode(ctx)) + } } - val updateUnsafeRowBuffer = unsafeRowBufferEvals.zipWithIndex.map { case (ev, i) => - val dt = updateExpr(i).dataType - CodeGenerator.updateColumn(unsafeRowBuffer, dt, i, ev, updateExpr(i).nullable) + + val aggCodeBlocks = updateExprs.indices.map { i => + val rowBufferEvalsForOneFunc = unsafeRowBufferEvals(i) + val boundUpdateExprsForOneFunc = boundUpdateExprs(i) + val bufferOffset = bufferStartOffsets(i) + + // All the update code for aggregation buffers should be placed in the end + // of each aggregation function code. + val updateRowBuffers = rowBufferEvalsForOneFunc.zipWithIndex.map { case (ev, j) => + val updateExpr = boundUpdateExprsForOneFunc(j) + val dt = updateExpr.dataType + val nullable = updateExpr.nullable + CodeGenerator.updateColumn(unsafeRowBuffer, dt, bufferOffset + j, ev, nullable) + } + code""" + |// evaluate aggregate function for ${aggNames(i)} + |${evaluateVariables(rowBufferEvalsForOneFunc)} + |// update unsafe row buffer + |${updateRowBuffers.mkString("\n").trim} + """.stripMargin + } + + lazy val nonSplitAggCode = { + s""" + |// common sub-expressions + |$effectiveCodes + |// evaluate aggregate functions and update aggregation buffers + |${aggCodeBlocks.fold(EmptyBlock)(_ + _)} + """.stripMargin + } + + if (conf.codegenSplitAggregateFunc && + aggCodeBlocks.map(_.length).sum > conf.methodSplitThreshold) { + val maybeSplitCode = splitAggregateExpressions( + ctx, aggNames, boundUpdateExprs, aggCodeBlocks, subExprs.states) + + maybeSplitCode.map { updateAggCode => + s""" + |// do aggregate + |// common sub-expressions + |$effectiveCodes + |// evaluate aggregate functions and update aggregation buffers + |$updateAggCode + """.stripMargin + }.getOrElse { + nonSplitAggCode + } + } else { + nonSplitAggCode } - s""" - |// common sub-expressions - |$effectiveCodes - |// evaluate aggregate function - |${evaluateVariables(unsafeRowBufferEvals)} - |// update unsafe row buffer - |${updateUnsafeRowBuffer.mkString("\n").trim} - """.stripMargin } val updateRowInHashMap: String = { if (isFastHashMapEnabled) { if (isVectorizedHashMapEnabled) { ctx.INPUT_ROW = fastRowBuffer - val boundUpdateExpr = bindReferences(updateExpr, inputAttr) - val subExprs = ctx.subexpressionEliminationForWholeStageCodegen(boundUpdateExpr) + val boundUpdateExprs = updateExprs.map { updateExprsForOneFunc => + bindReferences(updateExprsForOneFunc, inputAttr) + } + val subExprs = ctx.subexpressionEliminationForWholeStageCodegen(boundUpdateExprs.flatten) val effectiveCodes = subExprs.codes.mkString("\n") - val fastRowEvals = ctx.withSubExprEliminationExprs(subExprs.states) { - boundUpdateExpr.map(_.genCode(ctx)) + val fastRowEvals = boundUpdateExprs.map { boundUpdateExprsForOneFunc => + ctx.withSubExprEliminationExprs(subExprs.states) { + boundUpdateExprsForOneFunc.map(_.genCode(ctx)) + } } - val updateFastRow = fastRowEvals.zipWithIndex.map { case (ev, i) => - val dt = updateExpr(i).dataType - CodeGenerator.updateColumn( - fastRowBuffer, dt, i, ev, updateExpr(i).nullable, isVectorized = true) + + val aggCodeBlocks = fastRowEvals.zipWithIndex.map { case (fastRowEvalsForOneFunc, i) => + val boundUpdateExprsForOneFunc = boundUpdateExprs(i) + val bufferOffset = bufferStartOffsets(i) + // All the update code for aggregation buffers should be placed in the end + // of each aggregation function code. + val updateRowBuffer = fastRowEvalsForOneFunc.zipWithIndex.map { case (ev, j) => + val updateExpr = boundUpdateExprsForOneFunc(j) + val dt = updateExpr.dataType + val nullable = updateExpr.nullable + CodeGenerator.updateColumn(fastRowBuffer, dt, bufferOffset + j, ev, nullable, + isVectorized = true) + } + code""" + |// evaluate aggregate function for ${aggNames(i)} + |${evaluateVariables(fastRowEvalsForOneFunc)} + |// update fast row + |${updateRowBuffer.mkString("\n").trim} + """.stripMargin } - // If vectorized fast hash map is on, we first generate code to update row - // in vectorized fast hash map, if the previous loop up hit vectorized fast hash map. - // Otherwise, update row in regular hash map. - s""" - |if ($fastRowBuffer != null) { - | // common sub-expressions - | $effectiveCodes - | // evaluate aggregate function - | ${evaluateVariables(fastRowEvals)} - | // update fast row - | ${updateFastRow.mkString("\n").trim} - |} else { - | $updateRowInRegularHashMap - |} - """.stripMargin + lazy val nonSplitAggCode = { + // If vectorized fast hash map is on, we first generate code to update row + // in vectorized fast hash map, if the previous loop up hit vectorized fast hash map. + // Otherwise, update row in regular hash map. + s""" + |if ($fastRowBuffer != null) { + | // common sub-expressions + | $effectiveCodes + | // evaluate aggregate functions and update aggregation buffers + | ${aggCodeBlocks.fold(EmptyBlock)(_ + _)} Review comment: nice suggestion and I'll follow it. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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