java/vector/src/main/java/org/apache/arrow/vector/VariableWidthVector.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;

/**
 * Interface vectors that contain variable width members (e.g. Strings, Lists, etc).
 */
public interface VariableWidthVector extends ElementAddressableVector, DensityAwareVector {

  /**
   * Allocate a new memory space for this vector.  Must be called prior to using the ValueVector.
   *
   * @param totalBytes Desired size of the underlying data buffer.
   * @param valueCount Number of values in the vector.
   */
  void allocateNew(int totalBytes, int valueCount);

  /**
   * Allocate a new memory space for this vector.  Must be called prior to using the ValueVector.
   * The initial size in bytes is either default (or) reused from previous allocation
   *
   * @param valueCount Number of values in the vector.
   */
  void allocateNew(int valueCount);

  /**
   * Provide the maximum amount of variable width bytes that can be stored in this vector.
   *
   * @return the byte capacity of this vector
   */
  int getByteCapacity();

  /**
   * Provide the number of bytes contained in the valueBuffer.
   * @return the number of bytes in valueBuffer.
   */
  int sizeOfValueBuffer();
}