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.arrow.vector;
  
  import org.apache.arrow.memory.BufferAllocator;
  import org.apache.arrow.memory.util.ArrowBufPointer;
  import org.apache.arrow.memory.util.hash.ArrowBufHasher;
  import org.apache.arrow.vector.types.pojo.Field;
  import org.apache.arrow.vector.types.pojo.FieldType;
  import org.apache.arrow.vector.util.CallBack;
  import org.apache.arrow.vector.util.TransferPair;
  
  /** A zero length vector of any type. */
  public final class ZeroVector extends NullVector {
    public static final ZeroVector INSTANCE = new ZeroVector();
  
    /**
     * Instantiate a ZeroVector.
     *
     * @param name name of the vector
     */
    public ZeroVector(String name) {
      super(name);
    }
  
    /**
     * Instantiate a ZeroVector.
     *
     * @param name name of the vector
     * @param fieldType type of Field materialized by this vector.
     */
    public ZeroVector(String name, FieldType fieldType) {
      super(name, fieldType);
    }
  
    /**
     * Instantiate a ZeroVector.
     *
     * @param field field materialized by this vector.
     */
    public ZeroVector(Field field) {
      super(field);
    }
  
    @Deprecated
    public ZeroVector() {}
  
    @Override
    public int getValueCount() {
      return 0;
    }
  
    @Override
    public void setValueCount(int valueCount) {}
  
    @Override
    public int getNullCount() {
      return 0;
    }
  
    @Override
    public boolean isNull(int index) {
      throw new IndexOutOfBoundsException();
    }
  
    @Override
    public int hashCode(int index) {
      return 0;
    }
  
    @Override
    public int hashCode(int index, ArrowBufHasher hasher) {
      return ArrowBufPointer.NULL_HASH_CODE;
    }
  
    @Override
    public int getValueCapacity() {
      return 0;
    }
  
    @Override
    public TransferPair getTransferPair(BufferAllocator allocator) {
      return defaultPair;
    }
  
    @Override
    public TransferPair getTransferPair(String ref, BufferAllocator allocator) {
      return defaultPair;
    }
  
    @Override
    public TransferPair getTransferPair(String ref, BufferAllocator allocator, CallBack callBack) {
      return defaultPair;
    }
  
    @Override
    public TransferPair makeTransferPair(ValueVector target) {
      return defaultPair;
    }
  
    private final TransferPair defaultPair =
        new TransferPair() {
          @Override
          public void transfer() {}
  
          @Override
          public void splitAndTransfer(int startIndex, int length) {}
  
          @Override
          public ValueVector getTo() {
            return ZeroVector.this;
          }
  
          @Override
          public void copyValueSafe(int from, int to) {}
        };
  }
  