mirror of https://github.com/libAthena/athena.git
114 lines
2.9 KiB
Plaintext
114 lines
2.9 KiB
Plaintext
/* lzo1b_r.ch -- literal run handling for the the LZO1B/LZO1C algorithm
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This file is part of the LZO real-time data compression library.
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Copyright (C) 1996-2015 Markus Franz Xaver Johannes Oberhumer
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All Rights Reserved.
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The LZO library is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License as
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published by the Free Software Foundation; either version 2 of
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the License, or (at your option) any later version.
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The LZO library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with the LZO library; see the file COPYING.
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If not, write to the Free Software Foundation, Inc.,
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51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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Markus F.X.J. Oberhumer
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<markus@oberhumer.com>
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http://www.oberhumer.com/opensource/lzo/
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*/
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/***********************************************************************
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// store a literal run (internal)
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************************************************************************/
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LZO_LOCAL_IMPL(lzo_bytep)
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STORE_RUN(lzo_bytep const oo, const lzo_bytep const ii, lzo_uint r_len)
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{
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lzo_bytep op;
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const lzo_bytep ip;
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lzo_uint t;
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LZO_STATS(lzo_stats->literals += r_len);
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op = oo;
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ip = ii;
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assert(r_len > 0);
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/* code a long R0 run */
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if (r_len >= 512)
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{
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unsigned r_bits = 6; /* 256 << 6 == 16384 */
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lzo_uint tt = 32768u;
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while (r_len >= (t = tt))
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{
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r_len -= t;
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*op++ = 0;
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*op++ = (R0FAST - R0MIN) + 7;
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MEMCPY8_DS(op, ip, t);
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LZO_STATS(lzo_stats->r0long_runs++);
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}
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tt >>= 1;
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do
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{
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if (r_len >= (t = tt))
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{
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r_len -= t;
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*op++ = 0;
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*op++ = LZO_BYTE((R0FAST - R0MIN) + r_bits);
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MEMCPY8_DS(op, ip, t);
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LZO_STATS(lzo_stats->r0long_runs++);
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}
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tt >>= 1;
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}
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while (--r_bits > 0);
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}
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assert(r_len < 512);
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while (r_len >= (t = R0FAST))
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{
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r_len -= t;
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*op++ = 0;
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*op++ = (R0FAST - R0MIN);
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MEMCPY8_DS(op, ip, t);
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LZO_STATS(lzo_stats->r0fast_runs++);
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}
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t = r_len;
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if (t >= R0MIN)
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{
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/* code a short R0 run */
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*op++ = 0;
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*op++ = LZO_BYTE(t - R0MIN);
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MEMCPY_DS(op, ip, t);
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LZO_STATS(lzo_stats->r0short_runs++);
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}
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else if (t > 0)
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{
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/* code a short literal run */
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LZO_STATS(lzo_stats->lit_runs++);
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LZO_STATS(lzo_stats->lit_run[t]++);
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*op++ = LZO_BYTE(t);
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MEMCPY_DS(op, ip, t);
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}
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return op;
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}
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/* vim:set ts=4 sw=4 et: */
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