exec/java-exec/src/main/java/org/apache/drill/exec/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.drill.exec.vector;

public class AllocationHelper {
  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 RepeatedFixedWidthVector){
      ((RepeatedFixedWidthVector) v).allocateNew(valueCount, childValCount);
    }else if(v instanceof RepeatedVariableWidthVector){
      ((RepeatedVariableWidthVector) 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
   * @param valueCount
   * @return
   */
  public static boolean allocateNew(ValueVector v, int valueCount){
    if (v instanceof  FixedWidthVector) {
      ((FixedWidthVector) v).allocateNew(valueCount);
      return true;
    } else {
      return v.allocateNewSafe();
    }
  }

}