java/vector/src/main/java/org/apache/arrow/vector/AllocationHelper.java

/**
 * 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.vector.complex.RepeatedFixedWidthVectorLike;
import org.apache.arrow.vector.complex.RepeatedVariableWidthVectorLike;

public class AllocationHelper {
//  private static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(AllocationHelper.class);

  public static void allocate(ValueVector v, int valueCount, int bytesPerValue) {
    allocate(v, valueCount, bytesPerValue, 5);
  }

  public static void allocatePrecomputedChildCount(ValueVector v, int valueCount, int bytesPerValue, int childValCount){
    if(v instanceof FixedWidthVector) {
      ((FixedWidthVector) v).allocateNew(valueCount);
    } else if (v instanceof VariableWidthVector) {
      ((VariableWidthVector) v).allocateNew(valueCount * bytesPerValue, valueCount);
    } else if(v instanceof RepeatedFixedWidthVectorLike) {
      ((RepeatedFixedWidthVectorLike) v).allocateNew(valueCount, childValCount);
    } else if(v instanceof RepeatedVariableWidthVectorLike) {
      ((RepeatedVariableWidthVectorLike) v).allocateNew(childValCount * bytesPerValue, valueCount, childValCount);
    } else {
      v.allocateNew();
    }
  }

  public static void allocate(ValueVector v, int valueCount, int bytesPerValue, int repeatedPerTop){
    allocatePrecomputedChildCount(v, valueCount, bytesPerValue, repeatedPerTop * valueCount);
  }

  /**
   * Allocates the exact amount if v is fixed width, otherwise falls back to dynamic allocation
   * @param v value vector we are trying to allocate
   * @param valueCount  size we are trying to allocate
   * @throws org.apache.arrow.memory.OutOfMemoryException if it can't allocate the memory
   */
  public static void allocateNew(ValueVector v, int valueCount) {
    if (v instanceof  FixedWidthVector) {
      ((FixedWidthVector) v).allocateNew(valueCount);
    } else {
      v.allocateNew();
    }
  }
}