xref: /6.6.0/platform/include/platform/crc32c.h (revision 87c134a8)
1/* -*- Mode: C++; tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*- */
2/*
3 *     Copyright 2015 Couchbase, Inc
4 *
5 *   Licensed under the Apache License, Version 2.0 (the "License");
6 *   you may not use this file except in compliance with the License.
7 *   You may obtain a copy of the License at
8 *
9 *       http://www.apache.org/licenses/LICENSE-2.0
10 *
11 *   Unless required by applicable law or agreed to in writing, software
12 *   distributed under the License is distributed on an "AS IS" BASIS,
13 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 *   See the License for the specific language governing permissions and
15 *   limitations under the License.
16 */
17
18//
19// Generate a CRC-32C (Castagnolia)
20// CRC polynomial of 0x1EDC6F41
21//
22// When available a hardware assisted function is used for increased
23// performance.
24//
25#pragma once
26#include <platform/visibility.h>
27#include <cstddef>
28#include <cstdint>
29
30//
31// This module requires X86 for the HW assisted version of the function.
32// For now this #error is here because there's been no requirement for
33// a portable/non-X86 version of this function in Couchbase.
34// To fix will require refactoring to hide the X86 dependencies when
35// built on another platform.
36//
37#if !defined(__x86_64__) && !defined(_M_X64) && !defined(_M_IX86)
38#error "crc32c requires X86 SSE4.2 for hardware acceleration"
39#endif
40
41PLATFORM_PUBLIC_API
42uint32_t crc32c(const uint8_t* buf, size_t len, uint32_t crc_in);
43
44// The following methods are used by unit testing to force the calculation
45// of the checksum by using a given implementation.
46PLATFORM_PUBLIC_API
47uint32_t crc32c_sw(const uint8_t* buf, size_t len, uint32_t crc_in);
48PLATFORM_PUBLIC_API
49uint32_t crc32c_hw(const uint8_t* buf, size_t len, uint32_t crc_in);
50PLATFORM_PUBLIC_API
51uint32_t crc32c_hw_1way(const uint8_t* buf, size_t len, uint32_t crc_in);
52