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.arrow.constructor;
  
  import com.aliyun.odps.table.utils.Preconditions;
  import org.apache.arrow.vector.ValueVector;
  
  public abstract class ArrowFieldWriter<IN> {
  
      protected final ValueVector valueVector;
      protected int count = 0;
  
      public ArrowFieldWriter(ValueVector valueVector) {
          this.valueVector = Preconditions.checkNotNull(valueVector, "Value vector");
      }
  
      public int getCount() {
          return count;
      }
  
      public String getName() {
          return valueVector.getField().getName();
      }
  
      public void write(IN row, int ordinal) {
          if (isNullAt(row, ordinal)) {
              setNull();
          } else {
              setValue(row, ordinal);
          }
          count += 1;
      }
  
      public void finish() {
          valueVector.setValueCount(count);
      }
  
      public void reset() {
          valueVector.reset();
          count = 0;
      }
  
      protected abstract boolean isNullAt(IN row, int ordinal);
  
      protected abstract void setValue(IN row, int ordinal);
  
      protected abstract void setNull();
  }
  