mirror of https://github.com/libAthena/athena.git
118 lines
3.5 KiB
Plaintext
118 lines
3.5 KiB
Plaintext
/* lzo1b_cr.ch -- implementation of the LZO1B compression 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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/* WARNING: this file should *not* be used by applications. It is
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part of the implementation of the library and is subject
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to change.
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*/
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/***********************************************************************
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// store the current literal run
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************************************************************************/
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assert(ip < ip_end);
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if (pd(ip, ii) > 0)
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{
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lzo_uint t = pd(ip, ii);
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#if defined(LZO_HAVE_R1)
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if (ip == r1)
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{
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/* Code a context sensitive R1 match. */
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LZO_STATS(lzo_stats->literals += t);
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LZO_STATS(lzo_stats->r1_matches++);
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assert(t == 1);
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/* modify marker byte */
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assert((op[-2] >> M2O_BITS) == (M2_MARKER >> M2O_BITS));
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op[-2] &= M2O_MASK;
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assert((op[-2] >> M2O_BITS) == 0);
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/* copy 1 literal */
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*op++ = *ii++;
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r1 = ip + (M2_MIN_LEN + 1); /* set new R1 pointer */
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}
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else
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#endif
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if (t < R0MIN)
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{
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/* inline the copying of a short run */
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LZO_STATS(lzo_stats->literals += t);
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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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#if defined(LZO_HAVE_M3)
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if (t < LZO_SIZE(8 - M3O_BITS) && op == m3)
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{
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/* Code a very short literal run into the low offset bits
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* of the previous M3/M4 match.
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*/
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LZO_STATS(lzo_stats->lit_runs_after_m3_match++);
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LZO_STATS(lzo_stats->lit_run_after_m3_match[t]++);
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assert((m3[-2] >> M3O_BITS) == 0);
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m3[-2] = LZO_BYTE(m3[-2] | (t << M3O_BITS));
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}
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else
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#endif
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{
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*op++ = LZO_BYTE(t);
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}
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MEMCPY_DS(op, ii, t);
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#if defined(LZO_HAVE_R1)
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r1 = ip + (M2_MIN_LEN + 1); /* set new R1 pointer */
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#endif
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}
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else if (t < R0FAST)
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{
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/* inline the copying of a short R0 run */
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LZO_STATS(lzo_stats->literals += t);
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LZO_STATS(lzo_stats->r0short_runs++);
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*op++ = 0;
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*op++ = LZO_BYTE(t - R0MIN);
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MEMCPY_DS(op, ii, t);
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#if defined(LZO_HAVE_R1)
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r1 = ip + (M2_MIN_LEN + 1); /* set new R1 pointer */
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#endif
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}
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else
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{
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op = STORE_RUN(op, ii, t);
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ii = ip;
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}
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}
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/* ii now points to the start of the current match */
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assert(ii == ip);
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/* vim:set ts=4 sw=4 et: */
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