iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/execution/config/sys/subscription/ShowTopicsTask.java

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 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * 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
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
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package org.apache.iotdb.db.queryengine.plan.execution.config.sys.subscription;

import org.apache.iotdb.confignode.rpc.thrift.TShowTopicInfo;
import org.apache.iotdb.db.queryengine.common.header.ColumnHeader;
import org.apache.iotdb.db.queryengine.common.header.ColumnHeaderConstant;
import org.apache.iotdb.db.queryengine.common.header.DatasetHeaderFactory;
import org.apache.iotdb.db.queryengine.plan.execution.config.ConfigTaskResult;
import org.apache.iotdb.db.queryengine.plan.execution.config.IConfigTask;
import org.apache.iotdb.db.queryengine.plan.execution.config.executor.IConfigTaskExecutor;
import org.apache.iotdb.db.queryengine.plan.statement.metadata.subscription.ShowTopicsStatement;
import org.apache.iotdb.rpc.TSStatusCode;

import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.SettableFuture;
import org.apache.tsfile.common.conf.TSFileConfig;
import org.apache.tsfile.read.common.block.TsBlockBuilder;
import org.apache.tsfile.utils.Binary;

import java.util.List;
import java.util.stream.Collectors;

public class ShowTopicsTask implements IConfigTask {

  private final ShowTopicsStatement showTopicsStatement;

  public ShowTopicsTask(ShowTopicsStatement showTopicsStatement) {
    this.showTopicsStatement = showTopicsStatement;
  }

  @Override
  public ListenableFuture<ConfigTaskResult> execute(IConfigTaskExecutor configTaskExecutor)
      throws InterruptedException {
    return configTaskExecutor.showTopics(showTopicsStatement);
  }

  public static void buildTSBlock(
      List<TShowTopicInfo> topicInfoList, SettableFuture<ConfigTaskResult> future) {
    final TsBlockBuilder builder =
        new TsBlockBuilder(
            ColumnHeaderConstant.showTopicColumnHeaders.stream()
                .map(ColumnHeader::getColumnType)
                .collect(Collectors.toList()));

    for (final TShowTopicInfo topicInfo : topicInfoList) {
      builder.getTimeColumnBuilder().writeLong(0L);
      builder
          .getColumnBuilder(0)
          .writeBinary(new Binary(topicInfo.getTopicName(), TSFileConfig.STRING_CHARSET));
      builder
          .getColumnBuilder(1)
          .writeBinary(new Binary(topicInfo.getTopicAttributes(), TSFileConfig.STRING_CHARSET));
      builder.declarePosition();
    }

    future.set(
        new ConfigTaskResult(
            TSStatusCode.SUCCESS_STATUS,
            builder.build(),
            DatasetHeaderFactory.getShowTopicHeader()));
  }
}