content: /*
   * 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 "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.flink.streaming.connectors.influxdb;
  
  import org.apache.flink.configuration.Configuration;
  import org.apache.flink.streaming.api.functions.sink.RichSinkFunction;
  import org.apache.flink.util.CollectionUtil;
  import org.apache.flink.util.Preconditions;
  import org.apache.flink.util.StringUtils;
  import org.influxdb.InfluxDB;
  import org.influxdb.InfluxDBFactory;
  import org.influxdb.dto.Point;
  
  import java.util.concurrent.TimeUnit;
  
  /**
   * Sink to save data into a InfluxDB cluster.
   */
  public class InfluxDBSink extends RichSinkFunction<InfluxDBPoint> {
  
      private transient InfluxDB influxDBClient;
      private final InfluxDBConfig influxDBConfig;
  
      /**
       * Creates a new {@link InfluxDBSink} that connects to the InfluxDB server.
       *
       * @param influxDBConfig The configuration of {@link InfluxDBConfig}
       */
      public InfluxDBSink(InfluxDBConfig influxDBConfig) {
          this.influxDBConfig = Preconditions.checkNotNull(influxDBConfig, "InfluxDB client config should not be null");
      }
  
      /**
       * Initializes the connection to InfluxDB by either cluster or sentinels or single server.
       */
      @Override
      public void open(Configuration parameters) throws Exception {
          super.open(parameters);
  
          influxDBClient = InfluxDBFactory.connect(influxDBConfig.getUrl(), influxDBConfig.getUsername(), influxDBConfig.getPassword());
  
          if (!influxDBClient.databaseExists(influxDBConfig.getDatabase())) {
              if(influxDBConfig.isCreateDatabase()) {
                  influxDBClient.createDatabase(influxDBConfig.getDatabase());
              }
              else {
                  throw new RuntimeException("This " + influxDBConfig.getDatabase() + " database does not exist!");
              }
          }
  
          influxDBClient.setDatabase(influxDBConfig.getDatabase());
  
          if (influxDBConfig.getBatchActions() > 0) {
              influxDBClient.enableBatch(influxDBConfig.getBatchActions(), influxDBConfig.getFlushDuration(), influxDBConfig.getFlushDurationTimeUnit());
          }
  
          if (influxDBConfig.isEnableGzip()) {
  
              influxDBClient.enableGzip();
          }
      }
  
      /**
       * Called when new data arrives to the sink, and forwards it to InfluxDB.
       *
       * @param dataPoint {@link InfluxDBPoint}
       */
      @Override
      public void invoke(InfluxDBPoint dataPoint, Context context) throws Exception {
          if (StringUtils.isNullOrWhitespaceOnly(dataPoint.getMeasurement())) {
              throw new RuntimeException("No measurement defined");
          }
  
          Point.Builder builder = Point.measurement(dataPoint.getMeasurement())
                  .time(dataPoint.getTimestamp(), TimeUnit.MILLISECONDS);
  
          if (!CollectionUtil.isNullOrEmpty(dataPoint.getFields())) {
              builder.fields(dataPoint.getFields());
          }
  
          if (!CollectionUtil.isNullOrEmpty(dataPoint.getTags())) {
              builder.tag(dataPoint.getTags());
          }
  
          Point point = builder.build();
          influxDBClient.write(point);
      }
  
      @Override
      public void close() {
          if (influxDBClient.isBatchEnabled()) {
              influxDBClient.disableBatch();
          }
          influxDBClient.close();
      }
  }
  