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/* lzo1b_r.ch -- literal run handling for the the LZO1B/LZO1C 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/
*/
/***********************************************************************
// store a literal run (internal)
************************************************************************/
LZO_LOCAL_IMPL(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;
LZO_STATS(lzo_stats->literals += r_len);
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++ = (R0FAST - R0MIN) + 7;
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;
}
/* vim:set ts=4 sw=4 et: */
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