LogicalPostProject.java

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package org.apache.doris.nereids.trees.plans.logical;

import org.apache.doris.nereids.analyzer.Unbound;
import org.apache.doris.nereids.analyzer.UnboundStar;
import org.apache.doris.nereids.memo.GroupExpression;
import org.apache.doris.nereids.properties.DataTrait;
import org.apache.doris.nereids.properties.LogicalProperties;
import org.apache.doris.nereids.trees.expressions.Alias;
import org.apache.doris.nereids.trees.expressions.BoundStar;
import org.apache.doris.nereids.trees.expressions.Expression;
import org.apache.doris.nereids.trees.expressions.NamedExpression;
import org.apache.doris.nereids.trees.expressions.Slot;
import org.apache.doris.nereids.trees.expressions.functions.NoneMovableFunction;
import org.apache.doris.nereids.trees.expressions.literal.TinyIntLiteral;
import org.apache.doris.nereids.trees.plans.Plan;
import org.apache.doris.nereids.trees.plans.PlanType;
import org.apache.doris.nereids.trees.plans.algebra.Project;
import org.apache.doris.nereids.trees.plans.visitor.PlanVisitor;
import org.apache.doris.nereids.util.Utils;

import com.google.common.base.Preconditions;
import com.google.common.base.Supplier;
import com.google.common.base.Suppliers;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableList.Builder;
import com.google.common.collect.ImmutableSet;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.util.Optional;
import java.util.Set;

/**
 * Logical post project only use for load plan.
 */
public class LogicalPostProject<CHILD_TYPE extends Plan> extends LogicalUnary<CHILD_TYPE>
        implements Project, OutputPrunable {

    private final List<NamedExpression> projects;
    private final Supplier<Set<NamedExpression>> projectsSet;
    private final boolean isDistinct;

    public LogicalPostProject(List<NamedExpression> projects, CHILD_TYPE child) {
        this(projects, false, ImmutableList.of(child));
    }

    public LogicalPostProject(List<NamedExpression> projects, boolean isDistinct, List<Plan> child) {
        this(projects, isDistinct, Optional.empty(), Optional.empty(), child);
    }

    public LogicalPostProject(List<NamedExpression> projects, boolean isDistinct, Plan child) {
        this(projects, isDistinct,
                Optional.empty(), Optional.empty(), ImmutableList.of(child));
    }

    private LogicalPostProject(List<NamedExpression> projects, boolean isDistinct,
            Optional<GroupExpression> groupExpression, Optional<LogicalProperties> logicalProperties,
            List<Plan> child) {
        super(PlanType.LOGICAL_PROJECT, groupExpression, logicalProperties, child);
        Preconditions.checkArgument(projects != null, "projects can not be null");
        // only ColumnPrune rule may produce empty projects, this happens in rewrite phase
        // so if projects is empty, all plans have been bound already.
        Preconditions.checkArgument(!projects.isEmpty() || !(child instanceof Unbound),
                "projects can not be empty when child plan is unbound");
        this.projects = projects.isEmpty()
                ? ImmutableList.of(new Alias(new TinyIntLiteral((byte) 1)))
                : projects;
        this.projectsSet = Suppliers.memoize(() -> ImmutableSet.copyOf(this.projects));
        this.isDistinct = isDistinct;
    }

    /**
     * Get project list.
     *
     * @return all project of this node.
     */
    @Override
    public List<NamedExpression> getProjects() {
        return projects;
    }

    @Override
    public List<Slot> computeOutput() {
        Builder<Slot> slots = ImmutableList.builderWithExpectedSize(projects.size());
        for (NamedExpression project : projects) {
            slots.add(project.toSlot());
        }
        return slots.build();
    }

    @Override
    public String toString() {
        return Utils.toSqlString("LogicalPostProject[" + id.asInt() + "]",
                "distinct", isDistinct,
                "projects", projects);
    }

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

    @Override
    public List<? extends Expression> getExpressions() {
        return projects;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        LogicalPostProject<?> that = (LogicalPostProject<?>) o;
        boolean equal = projectsSet.get().equals(that.projectsSet.get())
                && isDistinct == that.isDistinct;
        // TODO: should add exprId for UnBoundStar and BoundStar for equality comparison
        if (!projects.isEmpty() && (projects.get(0) instanceof UnboundStar || projects.get(0) instanceof BoundStar)) {
            equal = child().getLogicalProperties().equals(that.child().getLogicalProperties());
        }
        return equal;
    }

    @Override
    public int hashCode() {
        return Objects.hash(projectsSet.get(), isDistinct);
    }

    @Override
    public LogicalPostProject<Plan> withChildren(List<Plan> children) {
        Preconditions.checkArgument(children.size() == 1);
        return new LogicalPostProject<>(projects, isDistinct, Utils.fastToImmutableList(children));
    }

    @Override
    public LogicalPostProject<Plan> withGroupExpression(Optional<GroupExpression> groupExpression) {
        return new LogicalPostProject<>(projects, isDistinct,
                groupExpression, Optional.of(getLogicalProperties()), children);
    }

    @Override
    public Plan withGroupExprLogicalPropChildren(Optional<GroupExpression> groupExpression,
            Optional<LogicalProperties> logicalProperties, List<Plan> children) {
        Preconditions.checkArgument(children.size() == 1);
        return new LogicalPostProject<>(projects, isDistinct,
                groupExpression, logicalProperties, children);
    }

    public LogicalPostProject<Plan> withProjects(List<NamedExpression> projects) {
        return new LogicalPostProject<>(projects, isDistinct, children);
    }

    public LogicalPostProject<Plan> withProjectsAndChild(List<NamedExpression> projects, Plan child) {
        return new LogicalPostProject<>(projects, isDistinct, ImmutableList.of(child));
    }

    public LogicalPostProject<Plan> withDistinct(boolean isDistinct) {
        return new LogicalPostProject<>(projects, isDistinct, children);
    }

    public boolean isDistinct() {
        return isDistinct;
    }

    @Override
    public List<NamedExpression> getOutputs() {
        return projects;
    }

    @Override
    public Plan pruneOutputs(List<NamedExpression> prunedOutputs) {
        List<NamedExpression> allProjects = new ArrayList<>(prunedOutputs);
        for (NamedExpression expression : projects) {
            if (expression.containsType(NoneMovableFunction.class)) {
                if (!prunedOutputs.contains(expression)) {
                    allProjects.add(expression);
                }
            }
        }
        return withProjects(allProjects);
    }

    @Override
    public JSONObject toJson() {
        JSONObject logicalProject = super.toJson();
        JSONObject properties = new JSONObject();
        properties.put("Projects", projects.toString());
        properties.put("IsDistinct", isDistinct);
        logicalProject.put("Properties", properties);
        return logicalProject;
    }

    @Override
    public void computeUnique(DataTrait.Builder builder) {
    }

    @Override
    public void computeUniform(DataTrait.Builder builder) {
    }

    @Override
    public void computeEqualSet(DataTrait.Builder builder) {
    }

    @Override
    public void computeFd(DataTrait.Builder builder) {
    }

    @Override
    public boolean canProcessProject(List<NamedExpression> parentProjects) {
        return false;
    }
}