LogicalSort.java

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

import org.apache.doris.nereids.memo.GroupExpression;
import org.apache.doris.nereids.properties.LogicalProperties;
import org.apache.doris.nereids.properties.OrderKey;
import org.apache.doris.nereids.trees.expressions.Expression;
import org.apache.doris.nereids.trees.expressions.Slot;
import org.apache.doris.nereids.trees.plans.Plan;
import org.apache.doris.nereids.trees.plans.PlanType;
import org.apache.doris.nereids.trees.plans.PropagateFuncDeps;
import org.apache.doris.nereids.trees.plans.algebra.Sort;
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.Suppliers;
import com.google.common.collect.ImmutableList;

import java.util.List;
import java.util.Objects;
import java.util.Optional;
import java.util.function.Supplier;

/**
 * Logical Sort plan.
 * <p>
 * eg: select * from table order by a, b desc;
 * orderKeys: list of column information after order by. eg:[a, asc],[b, desc].
 * OrderKey: Contains order expression information and sorting method. Default is ascending.
 */
public class LogicalSort<CHILD_TYPE extends Plan> extends LogicalUnary<CHILD_TYPE>
        implements Sort, PropagateFuncDeps {

    private final List<OrderKey> orderKeys;
    private final Supplier<List<? extends Expression>> expressions;

    public LogicalSort(List<OrderKey> orderKeys, CHILD_TYPE child) {
        this(orderKeys, Optional.empty(), Optional.empty(), child);
    }

    /**
     * Constructor for LogicalSort.
     */
    public LogicalSort(List<OrderKey> orderKeys, Optional<GroupExpression> groupExpression,
            Optional<LogicalProperties> logicalProperties, CHILD_TYPE child) {
        super(PlanType.LOGICAL_SORT, groupExpression, logicalProperties, child);
        this.orderKeys = Utils.fastToImmutableList(
                Objects.requireNonNull(orderKeys, "orderKeys can not be null")
        );
        this.expressions = Suppliers.memoize(() -> {
            ImmutableList.Builder<Expression> exprs
                    = ImmutableList.builderWithExpectedSize(orderKeys.size());
            for (OrderKey orderKey : orderKeys) {
                exprs.add(orderKey.getExpr());
            }
            return exprs.build();
        });
    }

    @Override
    public List<Slot> computeOutput() {
        return child().getOutput();
    }

    public List<OrderKey> getOrderKeys() {
        return orderKeys;
    }

    @Override
    public String toString() {
        return Utils.toSqlString("LogicalSort[" + id.asInt() + "]",
                "orderKeys", orderKeys);
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        LogicalSort<?> that = (LogicalSort<?>) o;
        return Objects.equals(orderKeys, that.orderKeys);
    }

    @Override
    public int hashCode() {
        return Objects.hash(orderKeys);
    }

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

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

    @Override
    public LogicalSort<Plan> withChildren(List<Plan> children) {
        Preconditions.checkArgument(children.size() == 1);
        return new LogicalSort<>(orderKeys, children.get(0));
    }

    @Override
    public LogicalSort<Plan> withGroupExpression(Optional<GroupExpression> groupExpression) {
        return new LogicalSort<>(orderKeys, groupExpression, Optional.of(getLogicalProperties()), child());
    }

    @Override
    public LogicalSort<Plan> withGroupExprLogicalPropChildren(Optional<GroupExpression> groupExpression,
            Optional<LogicalProperties> logicalProperties, List<Plan> children) {
        Preconditions.checkArgument(children.size() == 1);
        return new LogicalSort<>(orderKeys, groupExpression, logicalProperties, children.get(0));
    }

    public LogicalSort<Plan> withOrderKeys(List<OrderKey> orderKeys) {
        return new LogicalSort<>(orderKeys, Optional.empty(),
                Optional.of(getLogicalProperties()), child());
    }

    public LogicalSort<Plan> withOrderKeysAndChild(List<OrderKey> orderKeys, Plan child) {
        return new LogicalSort<>(orderKeys, child);
    }
}