com.speedment.runtime.core.internal.component.sql.optimizer.InitialFilterOptimizer Maven / Gradle / Ivy

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A Speedment bundle that shades all dependencies into one jar. This is useful when deploying an application on a server.

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/*
 *
 * Copyright (c) 2006-2019, Speedment, Inc. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); You may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at:
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package com.speedment.runtime.core.internal.component.sql.optimizer;

import com.speedment.runtime.core.component.sql.Metrics;
import com.speedment.runtime.core.component.sql.SqlStreamOptimizer;
import com.speedment.runtime.core.component.sql.SqlStreamOptimizerInfo;
import com.speedment.runtime.core.db.AsynchronousQueryResult;
import com.speedment.runtime.core.db.DbmsType;
import com.speedment.runtime.core.internal.stream.builder.action.reference.FilterAction;
import com.speedment.runtime.core.internal.stream.builder.streamterminator.StreamTerminatorUtil;
import com.speedment.runtime.core.stream.Pipeline;
import com.speedment.runtime.core.stream.action.Action;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.function.Consumer;
import java.util.function.Predicate;

import static com.speedment.runtime.core.internal.stream.builder.streamterminator.StreamTerminatorUtil.isContainingOnlyFieldPredicate;
import static java.util.Objects.requireNonNull;
import static java.util.stream.Collectors.toList;

/**
 * This Optimizer can take care of the case where there is a mix of Field
 * predicates and other predicates. Field predicates will be optimized and other
 * predicates will be applied in the stream.
 *
 * @author Per Minborg
 * @param  the entity type
 */
public final class InitialFilterOptimizer implements SqlStreamOptimizer {

    // Todo: A more general expression would be better. Eg. stream().peek().filter() would still be possible...
    // Todo: Allow CombinedPredicates
    @Override
    public Metrics metrics(Pipeline initialPipeline, DbmsType dbmsType) {
        requireNonNull(initialPipeline);
        requireNonNull(dbmsType);
        final AtomicInteger filterCounter = new AtomicInteger();
        traverse(initialPipeline, $ -> filterCounter.getAndIncrement());
        return Metrics.of(filterCounter.get(), filterCounter.get(), 0, 0, 0);
    }

    @Override
    public  P optimize(
        final P initialPipeline,
        final SqlStreamOptimizerInfo info,
        final AsynchronousQueryResult query
    ) {
        requireNonNull(initialPipeline);
        requireNonNull(info);
        requireNonNull(query);

        final List> filters = new ArrayList<>();
        traverse(initialPipeline, filters::add);

        final List