1 /*
2  * Copyright 2017 Google Inc. All rights reserved.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.google.flatbuffers;
18 
19 import static com.google.flatbuffers.Constants.*;
20 
21 import java.nio.ByteBuffer;
22 
23 /// @file
24 /// @addtogroup flatbuffers_java_api
25 /// @{
26 
27 /**
28  * Class that collects utility functions around `ByteBuffer`.
29  */
30 public class ByteBufferUtil {
31 
32 	/**
33      * Extract the size prefix from a `ByteBuffer`.
34      *
35      * @param bb a size-prefixed buffer
36      * @return the size prefix
37      */
getSizePrefix(ByteBuffer bb)38     public static int getSizePrefix(ByteBuffer bb) {
39         return bb.getInt(bb.position());
40     }
41 
42 	/**
43      * Create a duplicate of a size-prefixed `ByteBuffer` that has its position
44      * advanced just past the size prefix.
45      *
46      * @param bb a size-prefixed buffer
47      * @return a new buffer on the same underlying data that has skipped the
48      *         size prefix
49      */
removeSizePrefix(ByteBuffer bb)50     public static ByteBuffer removeSizePrefix(ByteBuffer bb) {
51         ByteBuffer s = bb.duplicate();
52         s.position(s.position() + SIZE_PREFIX_LENGTH);
53         return s;
54     }
55 
56 }
57 
58 /// @}
59