com.hazelcast.jet.sql.impl.connector.map.QueryUtil Maven / Gradle / Ivy

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/*
 * Copyright 2021 Hazelcast Inc.
 *
 * Licensed under the Hazelcast Community License (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://hazelcast.com/hazelcast-community-license
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.hazelcast.jet.sql.impl.connector.map;

import com.hazelcast.internal.serialization.InternalSerializationService;
import com.hazelcast.internal.serialization.SerializationService;
import com.hazelcast.internal.serialization.SerializationServiceAware;
import com.hazelcast.jet.sql.impl.connector.keyvalue.KvRowProjector;
import com.hazelcast.nio.ObjectDataInput;
import com.hazelcast.nio.ObjectDataOutput;
import com.hazelcast.nio.serialization.DataSerializable;
import com.hazelcast.projection.Projection;
import com.hazelcast.query.Predicate;
import com.hazelcast.query.PredicateBuilder;
import com.hazelcast.query.PredicateBuilder.EntryObject;
import com.hazelcast.query.Predicates;
import com.hazelcast.query.impl.getters.Extractors;
import com.hazelcast.sql.impl.QueryException;
import com.hazelcast.sql.impl.expression.ExpressionEvalContext;
import com.hazelcast.sql.impl.extract.QueryPath;
import com.hazelcast.sql.impl.row.JetSqlRow;
import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;

import java.io.IOException;
import java.util.List;
import java.util.Map.Entry;

final class QueryUtil {

    private QueryUtil() {
    }

    @SuppressWarnings({"unchecked", "rawtypes"})
    static Predicate toPredicate(
            JetSqlRow left,
            int[] leftEquiJoinIndices,
            int[] rightEquiJoinIndices,
            QueryPath[] rightPaths
    ) {
        PredicateBuilder builder = Predicates.newPredicateBuilder();
        EntryObject entryObject = builder.getEntryObject();
        for (int i = 0; i < leftEquiJoinIndices.length; i++) {
            Comparable leftValue = asComparable(left.get(leftEquiJoinIndices[i]));

            // might need a change when/if IS NOT DISTINCT FROM is supported
            if (leftValue == null) {
                return null;
            }

            QueryPath rightPath = rightPaths[rightEquiJoinIndices[i]];

            EntryObject object;
            if (rightPath.isKey()) {
                object = rightPath.isTop()
                        ? entryObject.key()
                        : entryObject.key().get(rightPath.getPath());
            } else {
                object = rightPath.isTop()
                        ? entryObject.get(rightPath.toString())
                        : entryObject.get(QueryPath.VALUE).get(rightPath.getPath());
            }
            if (i == 0) {
                object.equal(leftValue);
            } else {
                builder.and(object.equal(leftValue));
            }
        }
        return builder;
    }

    private static Comparable asComparable(Object value) {
        if (value == null) {
            return null;
        } else if (value instanceof Comparable) {
            return (Comparable) value;
        } else {
            throw QueryException.error("JOIN not supported for " + value.getClass() + ": not comparable");
        }
    }

    static Projection, JetSqlRow> toProjection(
            KvRowProjector.Supplier rightRowProjectorSupplier,
            ExpressionEvalContext evalContext
    ) {
        return new JoinProjection(rightRowProjectorSupplier, evalContext);
    }

    @SuppressFBWarnings(
            value = {"SE_BAD_FIELD", "SE_NO_SERIALVERSIONID"},
            justification = "the class is never java-serialized"
    )
    private static final class JoinProjection
            implements Projection, JetSqlRow>, DataSerializable, SerializationServiceAware {

        private KvRowProjector.Supplier rightRowProjectorSupplier;
        private List