MapContainsEntry.java

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package org.apache.doris.nereids.trees.expressions.functions.scalar;

import org.apache.doris.catalog.FunctionSignature;
import org.apache.doris.nereids.trees.expressions.Expression;
import org.apache.doris.nereids.trees.expressions.functions.ExplicitlyCastableSignature;
import org.apache.doris.nereids.trees.expressions.shape.TernaryExpression;
import org.apache.doris.nereids.trees.expressions.visitor.ExpressionVisitor;
import org.apache.doris.nereids.types.BooleanType;
import org.apache.doris.nereids.types.MapType;
import org.apache.doris.nereids.types.coercion.AnyDataType;
import org.apache.doris.nereids.types.coercion.FollowToAnyDataType;

import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;

import java.util.List;

/**
 * ScalarFunction 'map_contains_entry'.
 */
public class MapContainsEntry extends ScalarFunction
        implements TernaryExpression, ExplicitlyCastableSignature {

    /**
     * Basic signature, forcing search key/value type to convert to the same type as map's key/value type.
     */
    public static final List<FunctionSignature> FOLLOW_DATATYPE_SIGNATURE = ImmutableList.of(
            FunctionSignature.ret(BooleanType.INSTANCE)
                    .args(MapType.of(new AnyDataType(0), new AnyDataType(1)),
                            new FollowToAnyDataType(0),
                            new FollowToAnyDataType(1))
    );

    /**
     * This signature is used to calculate the correct wider type.
     * See {@link #getSignatures()}'s comment for details.
     */
    public static final List<FunctionSignature> MIN_COMMON_TYPE_SIGNATURES = ImmutableList.of(
            FunctionSignature.ret(BooleanType.INSTANCE)
                    .args(MapType.of(new AnyDataType(0), new AnyDataType(1)),
                            new AnyDataType(0),
                            new AnyDataType(1))
    );

    /**
     * constructor with 3 arguments.
     */
    public MapContainsEntry(Expression arg0, Expression arg1, Expression arg2) {
        super("map_contains_entry", arg0, arg1, arg2);
    }

    /** constructor for withChildren and reuse signature */
    public MapContainsEntry(ScalarFunctionParams functionParams) {
        super(functionParams);
    }

    /**
     * withChildren.
     */
    @Override
    public MapContainsEntry withChildren(List<Expression> children) {
        Preconditions.checkArgument(children.size() == 3);
        return new MapContainsEntry(getFunctionParams(children));
    }

    @Override
    public boolean nullable() {
        return child(0).nullable();
    }

    @Override
    public <R, C> R accept(ExpressionVisitor<R, C> visitor, C context) {
        return visitor.visitMapContainsEntry(this, context);
    }

    /**
     * See https://github.com/apache/doris/pull/44923
     * Uses AnyDataType instead of FollowToAnyDataType to allow Nereids to calculate the correct wider type,
     * allowing both map's key type and search key's type to convert to the same comparable and potentially wider type,
     * instead of forcing the search key's type to convert to the (potentially narrower) map key's type,
     * which could cause overflow and produce incorrect results.
     */
    @Override
    public List<FunctionSignature> getSignatures() {
        if (getArgument(0).getDataType().isMapType()) {
            MapType mapType = (MapType) getArgument(0).getDataType();
            if (mapType.getKeyType().isSameTypeForComplexTypeParam(getArgument(1).getDataType())
                    && mapType.getValueType().isSameTypeForComplexTypeParam(getArgument(2).getDataType())) {
                // return least common type
                return MIN_COMMON_TYPE_SIGNATURES;
            }
        }
        return FOLLOW_DATATYPE_SIGNATURE;
    }
}