ShowFrontendsCommand.java

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// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
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//
//   http://www.apache.org/licenses/LICENSE-2.0
//
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package org.apache.doris.nereids.trees.plans.commands;

import org.apache.doris.analysis.RedirectStatus;
import org.apache.doris.catalog.Column;
import org.apache.doris.catalog.Env;
import org.apache.doris.catalog.InfoSchemaDb;
import org.apache.doris.catalog.ScalarType;
import org.apache.doris.common.AnalysisException;
import org.apache.doris.common.ErrorCode;
import org.apache.doris.common.ErrorReport;
import org.apache.doris.common.proc.FrontendsProcNode;
import org.apache.doris.datasource.InternalCatalog;
import org.apache.doris.mysql.privilege.PrivPredicate;
import org.apache.doris.nereids.trees.plans.PlanType;
import org.apache.doris.nereids.trees.plans.visitor.PlanVisitor;
import org.apache.doris.qe.ConnectContext;
import org.apache.doris.qe.ShowResultSet;
import org.apache.doris.qe.ShowResultSetMetaData;
import org.apache.doris.qe.StmtExecutor;

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

import java.util.List;

/**
 * show frontends command
 */
public class ShowFrontendsCommand extends ShowCommand {
    private final String detail;

    /**
     * constructor
     */
    public ShowFrontendsCommand(String detail) {
        super(PlanType.SHOW_FRONTENDS_COMMAND);
        this.detail = detail;
    }

    /**
     * get Meta for show
     */
    public ShowResultSetMetaData getMetaData() {
        ShowResultSetMetaData.Builder builder = ShowResultSetMetaData.builder();

        ImmutableList<String> titles = FrontendsProcNode.TITLE_NAMES;
        if (detail != null && detail.equalsIgnoreCase("disks")) {
            titles = FrontendsProcNode.DISK_TITLE_NAMES;
        }
        for (String title : titles) {
            builder.addColumn(new Column(title, ScalarType.createVarchar(30)));
        }
        return builder.build();
    }

    @Override
    public ShowResultSet doRun(ConnectContext ctx, StmtExecutor executor) throws Exception {
        if (!Env.getCurrentEnv().getAccessManager().checkDbPriv(ConnectContext.get(),
                InternalCatalog.INTERNAL_CATALOG_NAME, InfoSchemaDb.DATABASE_NAME, PrivPredicate.SELECT)) {
            ErrorReport.reportAnalysisException(ErrorCode.ERR_DB_ACCESS_DENIED_ERROR,
                    PrivPredicate.SELECT.getPrivs().toString(), InfoSchemaDb.DATABASE_NAME);
        }

        if (detail != null && !detail.equalsIgnoreCase("disks")) {
            throw new AnalysisException("Show frontends with extra info only support show frontends disks");
        }

        List<List<String>> infos = Lists.newArrayList();
        FrontendsProcNode.getFrontendsInfo(Env.getCurrentEnv(), detail, infos);
        return new ShowResultSet(getMetaData(), infos);
    }

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

    @Override
    public RedirectStatus toRedirectStatus() {
        if (ConnectContext.get().getSessionVariable().getForwardToMaster()) {
            return RedirectStatus.FORWARD_NO_SYNC;
        } else {
            return RedirectStatus.NO_FORWARD;
        }
    }
}