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 com.aliyun.odps.table.write;
  
  import com.aliyun.odps.table.metrics.Metrics;
  
  import java.io.Closeable;
  import java.io.IOException;
  
  /**
   * A batch data writer returned by {@link TableBatchWriteSession} and is
   * responsible for writing data for an data partition.
   */
  public interface BatchWriter<T> extends Closeable {
  
      /**
       * Returns an new element for {@link BatchWriter#write}
       *
       * @return
       */
      T newElement();
  
      /**
       * Writes one element.
       * <p>
       * If this method fails (by throwing an exception), {@link #abort()} will be called
       *
       * @throws IOException if failure happens during IO.
       */
      void write(T record) throws IOException;
  
      /**
       * Aborts this writer if it is failed.
       */
      void abort() throws IOException;
  
      /**
       * Commits this writer after all records are written successfully, returns a commit message which
       * will be sent back to table sink
       */
      WriterCommitMessage commit() throws IOException;
  
      /**
       * Returns metrics for this writer
       */
      default Metrics currentMetricsValues() {
          return new Metrics();
      }
  
      /**
       * Flushes any buffered data to the underlying storage.
       * @throws IOException if failure happens during IO.
       */
      default void flush() throws IOException {
      }
  
  }
  