| /* |
| * Copyright 2019 Google Inc. All rights reserved. |
| * |
| * Licensed 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 com.google.flatbuffers; |
| |
| import java.nio.ByteBuffer; |
| |
| /// @cond FLATBUFFERS_INTERNAL |
| |
| /** |
| * All vector access objects derive from this class, and add their own accessors. |
| */ |
| public class BaseVector { |
| /** Used to hold the vector data position. */ |
| private int vector; |
| /** Used to hold the vector size. */ |
| private int length; |
| /** Used to hold the vector element size in table. */ |
| private int element_size; |
| /** The underlying ByteBuffer to hold the data of the vector. */ |
| protected ByteBuffer bb; |
| |
| /** |
| * Get the start data of a vector. |
| * |
| * @return Returns the start of the vector data. |
| */ |
| protected int __vector() { |
| return vector; |
| } |
| |
| /** |
| * Gets the element position in vector's ByteBuffer. |
| * |
| * @param j An `int` index of element into a vector. |
| * @return Returns the position of the vector element in a ByteBuffer. |
| */ |
| protected int __element(int j) { |
| return vector + j * element_size; |
| } |
| |
| /** |
| * Re-init the internal state with an external buffer {@code ByteBuffer}, an offset within and |
| * element size. |
| * |
| * This method exists primarily to allow recycling vector instances without risking memory leaks |
| * due to {@code ByteBuffer} references. |
| */ |
| protected void __reset(int _vector, int _element_size, ByteBuffer _bb) { |
| bb = _bb; |
| if (bb != null) { |
| vector = _vector; |
| length = bb.getInt(_vector - Constants.SIZEOF_INT); |
| element_size = _element_size; |
| } else { |
| vector = 0; |
| length = 0; |
| element_size = 0; |
| } |
| } |
| |
| /** |
| * Resets the internal state with a null {@code ByteBuffer} and a zero position. |
| * |
| * This method exists primarily to allow recycling vector instances without risking memory leaks |
| * due to {@code ByteBuffer} references. The instance will be unusable until it is assigned |
| * again to a {@code ByteBuffer}. |
| */ |
| public void reset() { |
| __reset(0, 0, null); |
| } |
| |
| /** |
| * Get the length of a vector. |
| * |
| * @return Returns the length of the vector. |
| */ |
| public int length() { |
| return length; |
| } |
| } |
| |
| /// @endcond |