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Diffstat (limited to 'src/lzo1a_cr.ch')
| -rw-r--r-- | src/lzo1a_cr.ch | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/src/lzo1a_cr.ch b/src/lzo1a_cr.ch new file mode 100644 index 0000000..62e1b27 --- /dev/null +++ b/src/lzo1a_cr.ch @@ -0,0 +1,128 @@ +/* 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) 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 LZO package and is subject + to change. + */ + + +#ifndef __LZO1A_CR_H +#define __LZO1A_CR_H + + +/*********************************************************************** +// code a literal run +************************************************************************/ + +static lzo_bytep +store_run(lzo_bytep const oo, const lzo_bytep const ii, lzo_uint r_len) +{ + register lzo_bytep op; + register const lzo_bytep ip; + register 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 */ + +/* +vi:ts=4:et +*/ + |