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authorArne Schwabe <arne@rfc2549.org>2012-04-16 19:21:14 +0200
committerArne Schwabe <arne@rfc2549.org>2012-04-16 19:21:14 +0200
commit3e4d8f433239c40311037616b1b8833a06651ae0 (patch)
tree98ab7fce0d011d34677b0beb762d389cb5c39199 /lzo/src/lzo1b_cr.ch
Initial import
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+/* lzo1b_cr.ch -- implementation of the LZO1B compression algorithm
+
+ This file is part of the LZO real-time data compression library.
+
+ Copyright (C) 2008 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 2007 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 2006 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 2005 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 2004 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 2003 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 2002 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 2001 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 2000 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 1999 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 1998 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 1997 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 1996 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 library and is subject
+ to change.
+ */
+
+
+
+/***********************************************************************
+// store the current literal run
+************************************************************************/
+
+ assert(ip < ip_end);
+ if (pd(ip,ii) > 0)
+ {
+ lzo_uint t = pd(ip,ii);
+
+#if defined(LZO_HAVE_R1)
+ if (ip == r1)
+ {
+ /* Code a context sensitive R1 match. */
+ LZO_STATS(lzo_stats->literals += t);
+ LZO_STATS(lzo_stats->r1_matches++);
+ assert(t == 1);
+ /* modify marker byte */
+ assert((op[-2] >> M2O_BITS) == (M2_MARKER >> M2O_BITS));
+ op[-2] &= M2O_MASK;
+ assert((op[-2] >> M2O_BITS) == 0);
+ /* copy 1 literal */
+ *op++ = *ii++;
+ r1 = ip + (M2_MIN_LEN + 1); /* set new R1 pointer */
+ }
+ else
+#endif
+ if (t < R0MIN)
+ {
+ /* inline the copying of a short run */
+ LZO_STATS(lzo_stats->literals += t);
+ LZO_STATS(lzo_stats->lit_runs++);
+ LZO_STATS(lzo_stats->lit_run[t]++);
+#if defined(LZO_HAVE_M3)
+ if (t < LZO_SIZE(8-M3O_BITS) && op == m3)
+ {
+ /* Code a very short literal run into the low offset bits
+ * of the previous M3/M4 match.
+ */
+ LZO_STATS(lzo_stats->lit_runs_after_m3_match++);
+ LZO_STATS(lzo_stats->lit_run_after_m3_match[t]++);
+ assert((m3[-2] >> M3O_BITS) == 0);
+ m3[-2] |= LZO_BYTE(t << M3O_BITS);
+ }
+ else
+#endif
+ {
+ *op++ = LZO_BYTE(t);
+ }
+ MEMCPY_DS(op, ii, t);
+#if defined(LZO_HAVE_R1)
+ r1 = ip + (M2_MIN_LEN + 1); /* set new R1 pointer */
+#endif
+ }
+ else if (t < R0FAST)
+ {
+ /* inline the copying of a short R0 run */
+ LZO_STATS(lzo_stats->literals += t);
+ LZO_STATS(lzo_stats->r0short_runs++);
+ *op++ = 0; *op++ = LZO_BYTE(t - R0MIN);
+ MEMCPY_DS(op, ii, t);
+#if defined(LZO_HAVE_R1)
+ r1 = ip + (M2_MIN_LEN + 1); /* set new R1 pointer */
+#endif
+ }
+ else
+ {
+ op = STORE_RUN(op,ii,t);
+ ii = ip;
+ }
+ }
+
+
+ /* ii now points to the start of the current match */
+ assert(ii == ip);
+
+
+/*
+vi:ts=4:et
+*/