IvmAggSumProcessor.java

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package org.apache.doris.mtmv.ivm.agg;

import org.apache.doris.nereids.trees.expressions.Add;
import org.apache.doris.nereids.trees.expressions.Expression;
import org.apache.doris.nereids.trees.expressions.functions.agg.AggregateFunction;
import org.apache.doris.nereids.trees.expressions.functions.agg.Sum;
import org.apache.doris.nereids.trees.expressions.functions.scalar.If;
import org.apache.doris.nereids.trees.expressions.literal.NullLiteral;

import com.google.common.collect.ImmutableList;

import java.util.List;

/** Processor for SUM(expr), using visible SUM plus hidden non-NULL count as persistent state. */
class IvmAggSumProcessor extends IvmAggSumLikeProcessor {
    @Override
    public boolean supportsOriginalFunction(AggregateFunction function) {
        return function instanceof Sum;
    }

    @Override
    public IvmAggFunctionKind handledFunctionKind() {
        return IvmAggFunctionKind.SUM;
    }

    @Override
    protected List<IvmAggStateKey> hiddenStateKeys(AggregateFunction function) {
        return ImmutableList.of(IvmAggStateKey.COUNT);
    }

    @Override
    public void appendApplyExpressions(IvmAggTarget target, IvmAggApplyContext applyContext) {
        IvmAggExpressionBuilder ctx = applyContext.expressions();
        Expression newSum = new Add(
                applyContext.oldMvSlotZeroIfNull(target.getVisibleSlot().getName()),
                applyContext.deltaSlotValue(target, IvmAggFunctionKind.SUM));
        Expression newCount = applyContext.buildNewHiddenCount(target);
        applyContext.putFinalExpression(target.getHiddenStateSlot(IvmAggStateKey.COUNT).getName(), newCount);
        Expression visibleValue = ctx.castIfNeeded(newSum, target.getVisibleSlot().getDataType());
        applyContext.putFinalExpression(target.getVisibleSlot().getName(),
                new If(ctx.isPositive(newCount), visibleValue,
                        new NullLiteral(target.getVisibleSlot().getDataType())));
    }
}