Mercurial > hg > nginx-quic
annotate src/core/ngx_crc.h @ 5529:e4adaa47af65
SPDY: store the length of frame instead of its whole size.
The "length" value better corresponds with the specification and reduces
confusion about whether frame's header is included in "size" or not.
Also this change simplifies some parts of code, since in more cases the
length of frame is more useful than its actual size, especially considering
that the size of frame header is constant.
author | Valentin Bartenev <vbart@nginx.com> |
---|---|
date | Wed, 22 Jan 2014 04:58:19 +0400 |
parents | d620f497c50f |
children |
rev | line source |
---|---|
441
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
208
diff
changeset
|
1 |
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
208
diff
changeset
|
2 /* |
444
42d11f017717
nginx-0.1.0-2004-09-29-20:00:49 import; remove years from copyright
Igor Sysoev <igor@sysoev.ru>
parents:
441
diff
changeset
|
3 * Copyright (C) Igor Sysoev |
4412 | 4 * Copyright (C) Nginx, Inc. |
441
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
208
diff
changeset
|
5 */ |
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
208
diff
changeset
|
6 |
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
208
diff
changeset
|
7 |
201
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
8 #ifndef _NGX_CRC_H_INCLUDED_ |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
9 #define _NGX_CRC_H_INCLUDED_ |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
10 |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
11 |
792 | 12 #include <ngx_config.h> |
13 #include <ngx_core.h> | |
14 | |
15 | |
201
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
16 /* 32-bit crc16 */ |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
17 |
776 | 18 static ngx_inline uint32_t |
789 | 19 ngx_crc(u_char *data, size_t len) |
201
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
20 { |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
21 uint32_t sum; |
208
0b67be7d4489
nginx-0.0.1-2003-12-08-23:48:12 import
Igor Sysoev <igor@sysoev.ru>
parents:
201
diff
changeset
|
22 |
201
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
23 for (sum = 0; len; len--) { |
441
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
208
diff
changeset
|
24 |
201
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
25 /* |
776 | 26 * gcc 2.95.2 x86 and icc 7.1.006 compile |
27 * that operator into the single "rol" opcode, | |
201
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
28 * msvc 6.0sp2 compiles it into four opcodes. |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
29 */ |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
30 sum = sum >> 1 | sum << 31; |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
31 |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
32 sum += *data++; |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
33 } |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
34 |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
35 return sum; |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
36 } |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
37 |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
38 |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
39 #endif /* _NGX_CRC_H_INCLUDED_ */ |