PushDownAggContext.java

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// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
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//
//   http://www.apache.org/licenses/LICENSE-2.0
//
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package org.apache.doris.nereids.rules.rewrite.eageraggregation;

import org.apache.doris.nereids.CascadesContext;
import org.apache.doris.nereids.trees.expressions.Alias;
import org.apache.doris.nereids.trees.expressions.Slot;
import org.apache.doris.nereids.trees.expressions.SlotReference;
import org.apache.doris.nereids.trees.expressions.functions.agg.AggregateFunction;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;

import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * PushDownAggContext
 */
public class PushDownAggContext {
    public static final int BIG_JOIN_BUILD_SIZE = 400_000;
    public final boolean hasDecomposedAggIf;
    private final List<AggregateFunction> aggFunctions;
    private final List<SlotReference> groupKeys;
    private final HashMap<AggregateFunction, Alias> aliasMap;
    private final Set<Slot> aggFunctionsInputSlots;

    // cascadesContext is used for normalizeAgg
    private final CascadesContext cascadesContext;

    private final boolean passThroughBigJoin;

    /**
     * constructor
     */
    public PushDownAggContext(List<AggregateFunction> aggFunctions,
            List<SlotReference> groupKeys, Map<AggregateFunction, Alias> aliasMap, CascadesContext cascadesContext,
            boolean passThroughBigJoin, boolean hasDecomposedAggIf) {
        this.groupKeys = groupKeys.stream().distinct().collect(Collectors.toList());
        this.aggFunctions = ImmutableList.copyOf(aggFunctions);
        this.cascadesContext = cascadesContext;

        HashMap<AggregateFunction, Alias> builtAliasMap = new HashMap<>();
        if (aliasMap == null) {
            for (AggregateFunction aggFunction : this.aggFunctions) {
                builtAliasMap.put(aggFunction, new Alias(aggFunction, aggFunction.getName()));
            }
        } else {
            for (AggregateFunction aggFunction : this.aggFunctions) {
                Alias alias = aliasMap.get(aggFunction);
                if (alias == null) {
                    alias = new Alias(aggFunction, aggFunction.getName());
                }
                builtAliasMap.put(aggFunction, alias);
            }
        }
        this.aliasMap = builtAliasMap;

        this.aggFunctionsInputSlots = aggFunctions.stream()
                .flatMap(aggFunction -> aggFunction.getInputSlots().stream())
                .filter(Slot.class::isInstance)
                .collect(ImmutableSet.toImmutableSet());
        this.passThroughBigJoin = passThroughBigJoin;
        this.hasDecomposedAggIf = hasDecomposedAggIf;
    }

    /**
     * check validation
     * @return true, if groupKeys is not empty and no group by key is in aggFunctionsInputSlots
     */
    public boolean isValid() {
        return !groupKeys.isEmpty()
                && !groupKeys.stream().anyMatch(s -> aggFunctionsInputSlots.contains(s));
    }

    public PushDownAggContext passThroughBigJoin() {
        return new PushDownAggContext(aggFunctions, groupKeys, aliasMap, cascadesContext,
                true, hasDecomposedAggIf);
    }

    public HashMap<AggregateFunction, Alias> getAliasMap() {
        return aliasMap;
    }

    public List<AggregateFunction> getAggFunctions() {
        return aggFunctions;
    }

    public List<SlotReference> getGroupKeys() {
        return groupKeys;
    }

    public PushDownAggContext withGroupKeys(List<SlotReference> groupKeys) {
        return new PushDownAggContext(aggFunctions, groupKeys, aliasMap,
                cascadesContext, passThroughBigJoin, hasDecomposedAggIf);
    }

    public Set<Slot> getAggFunctionsInputSlots() {
        return aggFunctionsInputSlots;
    }

    public CascadesContext getCascadesContext() {
        return cascadesContext;
    }

    public boolean isPassThroughBigJoin() {
        return passThroughBigJoin;
    }

    @Override
    public String toString() {
        return "PushDownAggContext{"
                + "aggFunctions=" + aggFunctions
                + ", groupKeys=" + groupKeys
                + ", aliasMap=" + aliasMap
                + ", passThroughBigJoin=" + passThroughBigJoin
                + '}';
    }
}