ShowCreateStreamCommand.java

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// distributed with this work for additional information
// 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
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.doris.nereids.trees.plans.commands;

import org.apache.doris.catalog.Column;
import org.apache.doris.catalog.DatabaseIf;
import org.apache.doris.catalog.Env;
import org.apache.doris.catalog.ScalarType;
import org.apache.doris.catalog.TableIf;
import org.apache.doris.catalog.stream.BaseStream;
import org.apache.doris.common.AnalysisException;
import org.apache.doris.common.ErrorCode;
import org.apache.doris.common.ErrorReport;
import org.apache.doris.info.TableNameInfo;
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.Lists;

import java.util.List;

/**
 * Represents the command for SHOW CREATE STREAM.
 */
public class ShowCreateStreamCommand extends ShowCommand {
    private static final ShowResultSetMetaData STREAM_META_DATA =
            ShowResultSetMetaData.builder()
                    .addColumn(new Column("Stream", ScalarType.createVarchar(20)))
                    .addColumn(new Column("Create Stream", ScalarType.createVarchar(30)))
                    .build();

    private final TableNameInfo tblNameInfo;

    public ShowCreateStreamCommand(TableNameInfo tableNameInfo) {
        super(PlanType.SHOW_CREATE_STREAM_COMMAND);
        this.tblNameInfo = tableNameInfo;
    }

    private void validate(ConnectContext ctx) throws AnalysisException {
        tblNameInfo.analyze(ctx);

        TableIf tableIf = Env.getCurrentEnv().getCatalogMgr()
                .getCatalogOrAnalysisException(tblNameInfo.getCtl())
                .getDbOrAnalysisException(tblNameInfo.getDb()).getTableOrAnalysisException(tblNameInfo.getTbl());

        if (!(tableIf instanceof BaseStream)) {
            ErrorReport.reportAnalysisException(tblNameInfo.toFullyQualified()
                    + " is not a stream, type:" + tableIf.getType());
        }

        PrivPredicate wanted;
        wanted = PrivPredicate.SHOW;

        if (!Env.getCurrentEnv().getAccessManager().checkTblPriv(ConnectContext.get(),
                tblNameInfo.getCtl(), tblNameInfo.getDb(), tblNameInfo.getTbl(), wanted)) {
            ErrorReport.reportAnalysisException(ErrorCode.ERR_TABLEACCESS_DENIED_ERROR, "SHOW CREATE TABLE",
                    ConnectContext.get().getQualifiedUser(),
                    ConnectContext.get().getRemoteIP(),
                    tblNameInfo.getDb() + ": " + tblNameInfo.getTbl());
        }
    }

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

    @Override
    public ShowResultSetMetaData getMetaData() {
        return STREAM_META_DATA;
    }

    @Override
    public ShowResultSet doRun(ConnectContext ctx, StmtExecutor executor) throws Exception {
        validate(ctx);
        // Fetch the catalog, database, and view metadata
        DatabaseIf db = ctx.getEnv().getCatalogMgr().getCatalogOrAnalysisException(tblNameInfo.getCtl())
                .getDbOrMetaException(tblNameInfo.getDb());
        TableIf stream = db.getTableOrMetaException(tblNameInfo.getTbl());

        if (!(stream instanceof BaseStream)) {
            ErrorReport.reportAnalysisException(ErrorCode.ERR_WRONG_OBJECT, tblNameInfo.getDb(), tblNameInfo.getTbl(),
                    "STREAM", "Use 'SHOW CREATE TABLE '" + tblNameInfo.getTbl());
        }

        List<List<String>> rows = Lists.newArrayList();
        // Lock the view to ensure consistent metadata access
        stream.readLock();
        try {
            List<String> createStreamStmt = Lists.newArrayList();
            ctx.getEnv().getDdlStmt(null, null, stream, createStreamStmt, null, null, false, true,
                    false, -1L, false, false);

            if (!createStreamStmt.isEmpty()) {
                rows.add(Lists.newArrayList(stream.getName(), createStreamStmt.get(0)));
            }
        } finally {
            stream.readUnlock();
        }

        // Set the result set and send it using the executor
        return new ShowResultSet(getMetaData(), rows);
    }
}