InnerProduct.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.exceptions.AnalysisException;
import org.apache.doris.nereids.trees.expressions.Expression;
import org.apache.doris.nereids.trees.expressions.functions.AlwaysNotNullable;
import org.apache.doris.nereids.trees.expressions.functions.ExplicitlyCastableSignature;
import org.apache.doris.nereids.trees.expressions.shape.BinaryExpression;
import org.apache.doris.nereids.trees.expressions.visitor.ExpressionVisitor;
import org.apache.doris.nereids.types.ArrayType;
import org.apache.doris.nereids.types.DataType;
import org.apache.doris.nereids.types.FloatType;
import org.apache.doris.nereids.types.MapType;
import org.apache.doris.nereids.types.coercion.AnyDataType;

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

import java.util.List;

/**
 * inner_product function
 */
public class InnerProduct extends ScalarFunction implements ExplicitlyCastableSignature,
        BinaryExpression, AlwaysNotNullable {

    public static final List<FunctionSignature> SIGNATURES = ImmutableList.of(
            FunctionSignature.ret(FloatType.INSTANCE)
                    .args(ArrayType.of(FloatType.INSTANCE), ArrayType.of(FloatType.INSTANCE)),
            FunctionSignature.ret(FloatType.INSTANCE)
                    .args(MapType.of(new AnyDataType(0), FloatType.INSTANCE),
                            MapType.of(new AnyDataType(0), FloatType.INSTANCE))
    );

    /**
     * constructor with 1 argument.
     */
    public InnerProduct(Expression arg0, Expression arg1) {
        super("inner_product", arg0, arg1);
    }

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

    @Override
    public void checkLegalityBeforeTypeCoercion() {
        checkMapKeyTypes(true);
    }

    @Override
    public void checkLegalityAfterRewrite() {
        checkMapKeyTypes(false);
    }

    private void checkMapKeyTypes(boolean allowNullKeyType) {
        DataType firstKeyType = null;
        for (Expression argument : getArguments()) {
            DataType argumentType = argument.getDataType();
            if (argumentType.isMapType()) {
                DataType keyType = ((MapType) argumentType).getKeyType();
                if (allowNullKeyType && keyType.isNullType()) {
                    continue;
                }
                if (!keyType.isIntegralType() && !keyType.isStringLikeType()) {
                    throw new AnalysisException("inner_product only supports integer or string map keys,"
                            + " but got " + keyType.toSql() + " in expression " + toSql());
                }
                if (firstKeyType != null && firstKeyType.isIntegralType() != keyType.isIntegralType()) {
                    throw new AnalysisException("inner_product requires map keys from the same type family,"
                            + " but got " + firstKeyType.toSql() + " and " + keyType.toSql()
                            + " in expression " + toSql());
                }
                firstKeyType = keyType;
            }
        }
    }

    /**
     * withChildren.
     */
    @Override
    public InnerProduct withChildren(List<Expression> children) {
        Preconditions.checkArgument(children.size() == 2);
        return new InnerProduct(getFunctionParams(children));
    }

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

    @Override
    public List<FunctionSignature> getSignatures() {
        return SIGNATURES;
    }
}