1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
|
/* lzo1a_cr.ch -- literal run handling for the the LZO1A algorithm
This file is part of the LZO real-time data compression library.
Copyright (C) 1996-2015 Markus Franz Xaver Johannes Oberhumer
All Rights Reserved.
The LZO library is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
The LZO library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with the LZO library; see the file COPYING.
If not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
Markus F.X.J. Oberhumer
<markus@oberhumer.com>
http://www.oberhumer.com/opensource/lzo/
*/
/* WARNING: this file should *not* be used by applications. It is
part of the implementation of the LZO package and is subject
to change.
*/
#ifndef __LZO1A_CR_H
#define __LZO1A_CR_H 1
/***********************************************************************
// code a literal run
************************************************************************/
static lzo_bytep
store_run(lzo_bytep const oo, const lzo_bytep const ii, lzo_uint r_len)
{
lzo_bytep op;
const lzo_bytep ip;
lzo_uint t;
op = oo;
ip = ii;
assert(r_len > 0);
/* code a long R0 run */
if (r_len >= 512)
{
unsigned r_bits = 6; /* 256 << 6 == 16384 */
lzo_uint tt = 32768u;
while (r_len >= (t = tt))
{
r_len -= t;
*op++ = 0; *op++ = (R0MAX - R0MIN);
MEMCPY8_DS(op, ip, t);
LZO_STATS(lzo_stats->r0long_runs++);
}
tt >>= 1;
do {
if (r_len >= (t = tt))
{
r_len -= t;
*op++ = 0; *op++ = LZO_BYTE((R0FAST - R0MIN) + r_bits);
MEMCPY8_DS(op, ip, t);
LZO_STATS(lzo_stats->r0long_runs++);
}
tt >>= 1;
} while (--r_bits > 0);
}
assert(r_len < 512);
while (r_len >= (t = R0FAST))
{
r_len -= t;
*op++ = 0; *op++ = (R0FAST - R0MIN);
MEMCPY8_DS(op, ip, t);
LZO_STATS(lzo_stats->r0fast_runs++);
}
t = r_len;
if (t >= R0MIN)
{
/* code a short R0 run */
*op++ = 0; *op++ = LZO_BYTE(t - R0MIN);
MEMCPY_DS(op, ip, t);
LZO_STATS(lzo_stats->r0short_runs++);
}
else if (t > 0)
{
/* code a short literal run */
LZO_STATS(lzo_stats->lit_runs++);
LZO_STATS(lzo_stats->lit_run[t]++);
*op++ = LZO_BYTE(t);
MEMCPY_DS(op, ip, t);
}
return op;
}
#endif /* already included */
/* vim:set ts=4 sw=4 et: */
|
