iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/execution/config/metadata/template/ShowSchemaTemplateTask.java

/*
 * 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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 * specific language governing permissions and limitations
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package org.apache.iotdb.db.queryengine.plan.execution.config.metadata.template;

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.DatasetHeader;
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.template.ShowSchemaTemplateStatement;
import org.apache.iotdb.db.schemaengine.template.Template;
import org.apache.iotdb.rpc.TSStatusCode;
import org.apache.iotdb.tsfile.common.conf.TSFileConfig;
import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
import org.apache.iotdb.tsfile.read.common.block.TsBlockBuilder;
import org.apache.iotdb.tsfile.utils.Binary;

import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.SettableFuture;

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

public class ShowSchemaTemplateTask implements IConfigTask {

  private final ShowSchemaTemplateStatement showSchemaTemplateStatement;

  public ShowSchemaTemplateTask(ShowSchemaTemplateStatement showSchemaTemplateStatement) {
    this.showSchemaTemplateStatement = showSchemaTemplateStatement;
  }

  @Override
  public ListenableFuture<ConfigTaskResult> execute(IConfigTaskExecutor configTaskExecutor)
      throws InterruptedException {
    return configTaskExecutor.showSchemaTemplate(this.showSchemaTemplateStatement);
  }

  public static void buildTSBlock(
      List<Template> templateList, SettableFuture<ConfigTaskResult> future) {
    List<TSDataType> outputDataTypes =
        ColumnHeaderConstant.showSchemaTemplateHeaders.stream()
            .map(ColumnHeader::getColumnType)
            .collect(Collectors.toList());
    TsBlockBuilder builder = new TsBlockBuilder(outputDataTypes);
    Optional<List<Template>> optional = Optional.ofNullable(templateList);
    optional
        .orElse(new ArrayList<>())
        .forEach(
            template -> {
              builder.getTimeColumnBuilder().writeLong(0L);
              builder
                  .getColumnBuilder(0)
                  .writeBinary(new Binary(template.getName(), TSFileConfig.STRING_CHARSET));
              builder.declarePosition();
            });
    DatasetHeader datasetHeader = DatasetHeaderFactory.getShowSchemaTemplateHeader();
    future.set(new ConfigTaskResult(TSStatusCode.SUCCESS_STATUS, builder.build(), datasetHeader));
  }
}