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Diffstat (limited to 'src/lzo1b_c.ch')
| -rw-r--r-- | src/lzo1b_c.ch | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/src/lzo1b_c.ch b/src/lzo1b_c.ch new file mode 100644 index 0000000..67ef4ff --- /dev/null +++ b/src/lzo1b_c.ch @@ -0,0 +1,270 @@ +/* lzo1b_c.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/ + */ + + + +/*********************************************************************** +// +************************************************************************/ + +#if !defined(LZO_HAVE_R1) && !defined(LZO_NO_R1) +# define LZO_HAVE_R1 +#endif + +#if !defined(LZO_HAVE_M3) && !defined(LZO_NO_M3) +# if (M3O_BITS < 8) +# define LZO_HAVE_M3 +# endif +#endif + + +#define MI +#define SI MI +#if (DD_BITS > 0) +#define DI ++ii; DVAL_NEXT(dv,ii); UPDATE_D(dict,drun,dv,ii,in); MI +#define XI assert(ii < ip); ii = ip; DVAL_FIRST(dv,(ip)); +#else +#define DI ++ii; DINDEX1(dindex,ii); UPDATE_I(dict,0,dindex,ii,in); MI +#define XI assert(ii < ip); ii = ip; +#endif + + +/*********************************************************************** +// compress a block of data. +// +// I really apologize for this spaghetti code. +************************************************************************/ + +LZO_PRIVATE(int) +do_compress ( const lzo_bytep in , lzo_uint in_len, + lzo_bytep out, lzo_uintp out_len, + lzo_voidp wrkmem ) +{ + register const lzo_bytep ip; +#if (DD_BITS > 0) +#if defined(__LZO_HASH_INCREMENTAL) + lzo_xint dv; +#endif + unsigned drun = 0; +#endif + lzo_bytep op; + const lzo_bytep const in_end = in + in_len; + const lzo_bytep const ip_end = in + in_len - MIN_LOOKAHEAD; + const lzo_bytep ii; +#if defined(LZO_HAVE_R1) + const lzo_bytep r1 = ip_end; /* pointer for R1 match (none yet) */ +#endif +#if defined(LZO_HAVE_M3) + lzo_bytep m3 = out + 1; /* pointer after last m3/m4 match */ +#endif + + lzo_dict_p const dict = (lzo_dict_p) wrkmem; + + +#if defined(LZO_COLLECT_STATS) + lzo_stats->r_bits = R_BITS; + lzo_stats->m3o_bits = M3O_BITS; + lzo_stats->dd_bits = DD_BITS; + lzo_stats->clevel = CLEVEL; + lzo_stats->d_bits = D_BITS; + lzo_stats->min_lookahead = MIN_LOOKAHEAD; + lzo_stats->max_lookbehind = MAX_LOOKBEHIND; + lzo_stats->compress_id = LZO_CPP_MACRO_EXPAND(COMPRESS_ID); +#endif + + /* init dictionary */ +#if defined(LZO_DETERMINISTIC) + BZERO8_PTR(wrkmem,sizeof(lzo_dict_t),D_SIZE); +#endif + + + op = out; + ip = in; + ii = ip; /* point to start of current literal run */ + + +#if (DD_BITS > 0) + DVAL_FIRST(dv,ip); + UPDATE_D(dict,drun,dv,ip,in); + ip++; + DVAL_NEXT(dv,ip); +#else + ip++; +#endif + + assert(ip < ip_end); + for (;;) + { + const lzo_bytep m_pos; +#if !defined(NDEBUG) + const lzo_bytep m_pos_sav = NULL; +#endif + lzo_uint m_off; +#if (DD_BITS == 0) + lzo_uint dindex; +#endif + lzo_uint m_len; + + +/*********************************************************************** +// search for a match +************************************************************************/ + +#if !defined(LZO_SEARCH_MATCH_INCLUDE_FILE) +# define LZO_SEARCH_MATCH_INCLUDE_FILE "lzo1b_sm.ch" +#endif + +#include LZO_SEARCH_MATCH_INCLUDE_FILE + + +#if !defined(LZO_TEST_MATCH_INCLUDE_FILE) +# define LZO_TEST_MATCH_INCLUDE_FILE "lzo1b_tm.ch" +#endif + +#include LZO_TEST_MATCH_INCLUDE_FILE + + + +/*********************************************************************** +// found a literal +************************************************************************/ + + + /* a literal */ +literal: +#if (DD_BITS == 0) + UPDATE_I(dict,0,dindex,ip,in); +#endif + if (++ip >= ip_end) + break; +#if (DD_BITS > 0) + DVAL_NEXT(dv,ip); +#endif + continue; + + + +/*********************************************************************** +// found a match +************************************************************************/ + +match: +#if (DD_BITS == 0) + UPDATE_I(dict,0,dindex,ip,in); +#endif + /* we have found a match of at least M2_MIN_LEN */ + + +#if !defined(LZO_CODE_RUN_INCLUDE_FILE) +# define LZO_CODE_RUN_INCLUDE_FILE "lzo1b_cr.ch" +#endif + +#include LZO_CODE_RUN_INCLUDE_FILE + + + /* ii now points to the start of the current match */ + assert(ii == ip); + + +/*********************************************************************** +// code the match +************************************************************************/ + +#if !defined(LZO_CODE_MATCH_INCLUDE_FILE) +# define LZO_CODE_MATCH_INCLUDE_FILE "lzo1b_cm.ch" +#endif + +#include LZO_CODE_MATCH_INCLUDE_FILE + + + /* ii now points to the start of the next literal run */ + assert(ii == ip); + + } + + +/*********************************************************************** +// end of block +************************************************************************/ + + assert(ip <= in_end); + +#if defined(LZO_COLLECT_STATS) + { + lzo_uint i; + const lzo_bytep p; + + for (i = 0; i < D_SIZE; i++) + { + p = dict[i]; + if (BOUNDS_CHECKING_OFF_IN_EXPR(p == NULL || p < in || p > in_end)) + lzo_stats->unused_dict_entries++; + } + lzo_stats->unused_dict_entries_percent = + 100.0 * lzo_stats->unused_dict_entries / D_SIZE; + } +#endif + + +#if defined(LZO_RETURN_IF_NOT_COMPRESSIBLE) + /* return if op == out to indicate that we + * couldn't compress and didn't copy anything. + */ + if (op == out) + { + *out_len = 0; + return LZO_E_NOT_COMPRESSIBLE; + } +#endif + + /* store the final literal run */ + if (pd(in_end,ii) > 0) + { + lzo_uint t = pd(in_end,ii); + op = STORE_RUN(op,ii,t); + } + + *out_len = pd(op, out); + return LZO_E_OK; /* compression went ok */ +} + + +/* +vi:ts=4:et +*/ |