PlanPreprocessors.java

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package org.apache.doris.nereids.processor.pre;

import org.apache.doris.nereids.StatementContext;
import org.apache.doris.nereids.trees.plans.logical.LogicalPlan;

import com.google.common.collect.ImmutableList;

import java.util.List;
import java.util.Objects;

/**
 * PlanPreprocessors: before copy the plan into the memo, we use this rewriter to rewrite plan by visitor.
 */
public class PlanPreprocessors {
    private final StatementContext statementContext;

    public PlanPreprocessors(StatementContext statementContext) {
        this.statementContext = Objects.requireNonNull(statementContext, "statementContext can not be null");
    }

    public LogicalPlan process(LogicalPlan logicalPlan) {
        LogicalPlan resultPlan = logicalPlan;
        for (PlanPreprocessor processor : getProcessors()) {
            resultPlan = (LogicalPlan) resultPlan.accept(processor, statementContext);
        }
        return resultPlan;
    }

    /**
     * get preprocessors before doing optimize
     * @return preprocessors
     */
    public List<PlanPreprocessor> getProcessors() {
        // add processor if we need
        return ImmutableList.of(
                new TurnOffPageCacheForInsertIntoSelect(),
                new PullUpSubqueryAliasToCTE()
        );
    }
}