iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/execution/operator/schema/source/ISchemaSource.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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 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
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package org.apache.iotdb.db.queryengine.execution.operator.schema.source;

import org.apache.iotdb.db.queryengine.common.header.ColumnHeader;
import org.apache.iotdb.db.schemaengine.schemaregion.ISchemaRegion;
import org.apache.iotdb.db.schemaengine.schemaregion.read.resp.info.ISchemaInfo;
import org.apache.iotdb.db.schemaengine.schemaregion.read.resp.reader.ISchemaReader;
import org.apache.iotdb.tsfile.read.common.block.TsBlockBuilder;

import java.util.List;

public interface ISchemaSource<T extends ISchemaInfo> {

  /**
   * Get the SchemaReader for iterating target SchemaInfo from given SchemaRegion.
   *
   * @return the SchemaReader for SchemaInfo T
   */
  ISchemaReader<T> getSchemaReader(ISchemaRegion schemaRegion);

  /** Get the column headers of the result TsBlock for SchemaInfo query. */
  List<ColumnHeader> getInfoQueryColumnHeaders();

  /**
   * Transform the SchemaInfo T to fill the TsBlock.
   *
   * @param schemaInfo the SchemaInfo need to be processed
   * @param tsBlockBuilder the target TsBlockBuilder using for generating TsBlock
   * @param database the belonged databased of given SchemaInfo
   */
  void transformToTsBlockColumns(T schemaInfo, TsBlockBuilder tsBlockBuilder, String database);

  boolean hasSchemaStatistic(ISchemaRegion schemaRegion);

  long getSchemaStatistic(ISchemaRegion schemaRegion);
}