UnassignedScanSingleRemoteTableJob.java

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package org.apache.doris.nereids.trees.plans.distribute.worker.job;

import org.apache.doris.nereids.StatementContext;
import org.apache.doris.nereids.trees.plans.distribute.DistributeContext;
import org.apache.doris.nereids.trees.plans.distribute.worker.DistributedPlanWorker;
import org.apache.doris.nereids.trees.plans.distribute.worker.DistributedPlanWorkerManager;
import org.apache.doris.nereids.trees.plans.distribute.worker.ScanWorkerSelector;
import org.apache.doris.planner.ExchangeNode;
import org.apache.doris.planner.PlanFragment;
import org.apache.doris.planner.ScanNode;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ListMultimap;

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

/**
 * UnassignedScanSingleRemoteTableJob
 * it should be a leaf job which not contains scan native olap table node,
 * for example, select literal without table, or scan an external table
 */
public class UnassignedScanSingleRemoteTableJob extends AbstractUnassignedScanJob {
    private final ScanWorkerSelector scanWorkerSelector;

    public UnassignedScanSingleRemoteTableJob(
            StatementContext statementContext, PlanFragment fragment, ScanNode scanNode,
            ListMultimap<ExchangeNode, UnassignedJob> exchangeToChildJob, ScanWorkerSelector scanWorkerSelector) {
        super(statementContext, fragment, ImmutableList.of(scanNode), exchangeToChildJob);
        this.scanWorkerSelector = Objects.requireNonNull(scanWorkerSelector, "scanWorkerSelector is not null");
    }

    @Override
    protected Map<DistributedPlanWorker, UninstancedScanSource> multipleMachinesParallelization(
            DistributeContext distributeContext, ListMultimap<ExchangeNode, AssignedJob> inputJobs) {
        return scanWorkerSelector.selectReplicaAndWorkerWithoutBucket(
                scanNodes.get(0), statementContext.getConnectContext()
        );
    }

    @Override
    protected List<AssignedJob> fillUpAssignedJobs(List<AssignedJob> assignedJobs,
            DistributedPlanWorkerManager workerManager, ListMultimap<ExchangeNode, AssignedJob> inputJobs) {
        if (assignedJobs.isEmpty()) {
            // the file scan have pruned, so no assignedJobs,
            // we should allocate an instance of it,
            assignedJobs = fillUpSingleEmptyInstance(workerManager);
        }
        return assignedJobs;
    }
}