ceph/src/arrow/java/vector/src/main/java/org/apache/arrow/vector/ZeroVector.java

   1 /*
   2  * Licensed to the Apache Software Foundation (ASF) under one or more
   3  * contributor license agreements.  See the NOTICE file distributed with
   4  * this work for additional information regarding copyright ownership.
   5  * The ASF licenses this file to You under the Apache License, Version 2.0
   6  * (the "License"); you may not use this file except in compliance with
   7  * the License.  You may obtain a copy of the License at
   8  *
   9  *    http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 package org.apache.arrow.vector;
  19
  20 import org.apache.arrow.memory.BufferAllocator;
  21 import org.apache.arrow.memory.util.ArrowBufPointer;
  22 import org.apache.arrow.memory.util.hash.ArrowBufHasher;
  23 import org.apache.arrow.vector.types.pojo.Field;
  24 import org.apache.arrow.vector.types.pojo.FieldType;
  25 import org.apache.arrow.vector.util.CallBack;
  26 import org.apache.arrow.vector.util.TransferPair;
  27
  28 /**
  29  * A zero length vector of any type.
  30  */
  31 public final class ZeroVector extends NullVector {
  32   public static final ZeroVector INSTANCE = new ZeroVector();
  33
  34   /**
  35    * Instantiate a ZeroVector.
  36    *
  37    * @param name name of the vector
  38    */
  39   public ZeroVector(String name) {
  40     super(name);
  41   }
  42
  43   /**
  44    * Instantiate a ZeroVector.
  45    *
  46    * @param name      name of the vector
  47    * @param fieldType type of Field materialized by this vector.
  48    */
  49   public ZeroVector(String name, FieldType fieldType) {
  50     super(name, fieldType);
  51   }
  52
  53   /**
  54    * Instantiate a ZeroVector.
  55    *
  56    * @param field field materialized by this vector.
  57    */
  58   public ZeroVector(Field field) {
  59     super(field);
  60   }
  61
  62   @Deprecated
  63   public ZeroVector() {
  64   }
  65
  66   @Override
  67   public int getValueCount() {
  68     return 0;
  69   }
  70
  71   @Override
  72   public void setValueCount(int valueCount) {
  73   }
  74
  75   @Override
  76   public int getNullCount() {
  77     return 0;
  78   }
  79
  80   @Override
  81   public boolean isNull(int index) {
  82     throw new IndexOutOfBoundsException();
  83   }
  84
  85   @Override
  86   public int hashCode(int index) {
  87     return 0;
  88   }
  89
  90   @Override
  91   public int hashCode(int index, ArrowBufHasher hasher) {
  92     return ArrowBufPointer.NULL_HASH_CODE;
  93   }
  94
  95   @Override
  96   public int getValueCapacity() {
  97     return 0;
  98   }
  99
 100   @Override
 101   public TransferPair getTransferPair(BufferAllocator allocator) {
 102     return defaultPair;
 103   }
 104
 105   @Override
 106   public TransferPair getTransferPair(String ref, BufferAllocator allocator) {
 107     return defaultPair;
 108   }
 109
 110   @Override
 111   public TransferPair getTransferPair(String ref, BufferAllocator allocator, CallBack callBack) {
 112     return defaultPair;
 113   }
 114
 115   @Override
 116   public TransferPair makeTransferPair(ValueVector target) {
 117     return defaultPair;
 118   }
 119
 120   private final TransferPair defaultPair = new TransferPair() {
 121     @Override
 122     public void transfer() {
 123     }
 124
 125     @Override
 126     public void splitAndTransfer(int startIndex, int length) {
 127     }
 128
 129     @Override
 130     public ValueVector getTo() {
 131       return ZeroVector.this;
 132     }
 133
 134     @Override
 135     public void copyValueSafe(int from, int to) {
 136     }
 137   };
 138 }