integration-test/src/main/java/org/apache/iotdb/db/query/udf/example/Multiplier.java

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 * 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
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 * Unless required by applicable law or agreed to in writing,
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package org.apache.iotdb.db.query.udf.example;

import org.apache.iotdb.udf.api.UDTF;
import org.apache.iotdb.udf.api.access.Row;
import org.apache.iotdb.udf.api.collector.PointCollector;
import org.apache.iotdb.udf.api.customizer.config.UDTFConfigurations;
import org.apache.iotdb.udf.api.customizer.parameter.UDFParameterValidator;
import org.apache.iotdb.udf.api.customizer.parameter.UDFParameters;
import org.apache.iotdb.udf.api.customizer.strategy.RowByRowAccessStrategy;
import org.apache.iotdb.udf.api.type.Type;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class Multiplier implements UDTF {

  private static final Logger logger = LoggerFactory.getLogger(Multiplier.class);

  private long a;
  private long b;

  @Override
  public void validate(UDFParameterValidator validator) throws Exception {
    validator.validateInputSeriesNumber(1).validateInputSeriesDataType(0, Type.INT64);
  }

  @Override
  public void beforeStart(UDFParameters parameters, UDTFConfigurations configurations) {
    logger.debug("Multiplier#beforeStart");
    a = parameters.getLongOrDefault("a", 0);
    b = parameters.getLongOrDefault("b", 0);
    configurations.setOutputDataType(Type.INT64).setAccessStrategy(new RowByRowAccessStrategy());
  }

  @Override
  public void transform(Row row, PointCollector collector) throws Exception {
    collector.putLong(row.getTime(), row.getLong(0) * a * b);
  }

  @Override
  public void beforeDestroy() {
    logger.debug("Multiplier#beforeDestroy");
  }
}