1/********************************************************************
2 * Copyright (c) 2013 - 2014, Pivotal Inc.
3 * All rights reserved.
4 *
5 * Author: Zhanwei Wang
6 ********************************************************************/
7/********************************************************************
8 * 2014 -
9 * open source under Apache License Version 2.0
10 ********************************************************************/
11/**
12 * Licensed to the Apache Software Foundation (ASF) under one
13 * or more contributor license agreements. See the NOTICE file
14 * distributed with this work for additional information
15 * regarding copyright ownership. The ASF licenses this file
16 * to you under the Apache License, Version 2.0 (the
17 * "License"); you may not use this file except in compliance
18 * with the License. You may obtain a copy of the License at
19 *
20 * http://www.apache.org/licenses/LICENSE-2.0
21 *
22 * Unless required by applicable law or agreed to in writing, software
23 * distributed under the License is distributed on an "AS IS" BASIS,
24 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
25 * See the License for the specific language governing permissions and
26 * limitations under the License.
27 */
28#ifndef _HDFS_LIBHDFS3_COMMON_HWCHECKSUM_H_
29#define _HDFS_LIBHDFS3_COMMON_HWCHECKSUM_H_
30
31#include "Checksum.h"
32
33namespace Hdfs {
34namespace Internal {
35
36/**
37 * Calculate CRC with hardware support.
38 */
39class HWCrc32c: public Checksum {
40public:
41 /**
42 * Constructor.
43 */
44 HWCrc32c() :
45 crc(0xFFFFFFFF) {
46 }
47
48 uint32_t getValue() {
49 return ~crc;
50 }
51
52 /**
53 * @ref Checksum#reset()
54 */
55 void reset() {
56 crc = 0xFFFFFFFF;
57 }
58
59 /**
60 * @ref Checksum#update(const void *, int)
61 */
62 void update(const void * b, int len);
63
64 /**
65 * Destory an HWCrc32 instance.
66 */
67 ~HWCrc32c() {
68 }
69
70 /**
71 * To test if the hardware support this function.
72 * @return true if the hardware support to calculate the CRC.
73 */
74 static bool available();
75
76private:
77 void updateInt64(const char * b, int len);
78
79private:
80 uint32_t crc;
81};
82
83}
84}
85
86#endif /* _HDFS_LIBHDFS3_COMMON_HWCHECKSUM_H_ */
87