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Diffstat (limited to 'src/lzo1c_9x.c')
| -rw-r--r-- | src/lzo1c_9x.c | 382 |
1 files changed, 382 insertions, 0 deletions
diff --git a/src/lzo1c_9x.c b/src/lzo1c_9x.c new file mode 100644 index 0000000..4b7091f --- /dev/null +++ b/src/lzo1c_9x.c @@ -0,0 +1,382 @@ +/* lzo1c_9x.c -- implementation of the LZO1C-999 compression algorithm + + This file is part of the LZO real-time data compression library. + + Copyright (C) 2011 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2010 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2009 Markus Franz Xaver Johannes Oberhumer + 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/ + */ + + +#include "config1c.h" + + +/*********************************************************************** +// +************************************************************************/ + +#define SWD_N 16383 /* size of ring buffer */ +#define SWD_THRESHOLD 2 /* lower limit for match length */ +#define SWD_F 2048 /* upper limit for match length */ + + +#define LZO1C 1 +#define LZO_COMPRESS_T lzo1c_999_t +#define lzo_swd_t lzo1c_999_swd_t +#include "lzo_mchw.ch" + + + +/*********************************************************************** +// +************************************************************************/ + +static lzo_bytep +code_match ( LZO_COMPRESS_T *c, lzo_bytep op, lzo_uint m_len, lzo_uint m_off ) +{ + if (m_len <= M2_MAX_LEN && m_off <= M2_MAX_OFFSET) + { + assert(m_len >= M2_MIN_LEN); + assert(m_off >= M2_MIN_OFFSET); + + m_off -= M2_MIN_OFFSET; + /* code match len + low offset bits */ + *op++ = LZO_BYTE(((m_len - (M2_MIN_LEN - 2)) << M2O_BITS) | + (m_off & M2O_MASK)); + /* code high offset bits */ + *op++ = LZO_BYTE(m_off >> M2O_BITS); + c->m2_m++; + } + else + { + assert(m_len >= M3_MIN_LEN); + assert(m_off <= M3_MAX_OFFSET); + + m_off -= M3_MIN_OFFSET - M3_EOF_OFFSET; + /* code match len */ + if (m_len <= M3_MAX_LEN) + *op++ = LZO_BYTE(M3_MARKER | (m_len - (M3_MIN_LEN - 1))); + else + { + assert(m_len >= M4_MIN_LEN); + /* code M4 match len flag */ + *op++ = M4_MARKER; + /* code match len */ + m_len -= M4_MIN_LEN - 1; + while (m_len > 255) + { + m_len -= 255; + *op++ = 0; + } + assert(m_len > 0); + *op++ = LZO_BYTE(m_len); + } + /* code low offset bits */ + *op++ = LZO_BYTE(m_off & M3O_MASK); + /* code high offset bits */ + *op++ = LZO_BYTE(m_off >> M3O_BITS); + + c->r1_m_len = 0; + c->m3 = op; + c->m3_m++; + } + return op; +} + + +/*********************************************************************** +// this is a public function, but there is no prototype in a header file +************************************************************************/ + +LZO_EXTERN(int) +lzo1c_999_compress_callback ( const lzo_bytep in , lzo_uint in_len, + lzo_bytep out, lzo_uintp out_len, + lzo_voidp wrkmem, + lzo_callback_p cb, + lzo_uint max_chain ); + +LZO_PUBLIC(int) +lzo1c_999_compress_callback ( const lzo_bytep in , lzo_uint in_len, + lzo_bytep out, lzo_uintp out_len, + lzo_voidp wrkmem, + lzo_callback_p cb, + lzo_uint max_chain ) +{ + lzo_bytep op; + const lzo_bytep ii; + lzo_uint lit; + lzo_uint m_len, m_off; + LZO_COMPRESS_T cc; + LZO_COMPRESS_T * const c = &cc; + lzo_swd_p const swd = (lzo_swd_p) wrkmem; + int r; + + /* sanity check */ + LZO_COMPILE_TIME_ASSERT(LZO1C_999_MEM_COMPRESS >= SIZEOF_LZO_SWD_T) + + c->init = 0; + c->ip = c->in = in; + c->in_end = in + in_len; + c->cb = cb; + c->r1_r = c->m3_r = c->m2_m = c->m3_m = 0; + + op = out; + ii = c->ip; /* point to start of literal run */ + lit = 0; + c->r1_m_len = 0; + c->m3 = out + 1; /* pointer after last m3/m4 match */ + + r = init_match(c,swd,NULL,0,0); + if (r != 0) + return r; + if (max_chain > 0) + swd->max_chain = max_chain; + + r = find_match(c,swd,0,0); + if (r != 0) + return r; + while (c->look > 0) + { + int lazy_match_min_gain = -1; + lzo_uint ahead = 0; + + m_len = c->m_len; + m_off = c->m_off; + +#if 0 + printf("%5ld: %5d len:%3d off:%5d\n", (c->ip-c->look)-in, c->look, + m_len, m_off); +#endif + + assert(c->ip - c->look >= in); + if (lit == 0) + ii = c->ip - c->look; + assert(ii + lit == c->ip - c->look); + assert(swd->b_char == *(c->ip - c->look)); + + if ((m_len < M2_MIN_LEN) || + (m_len < M3_MIN_LEN && m_off > M2_MAX_OFFSET)) + { + m_len = 0; + } + else + { + assert(c->ip - c->look - m_off >= in); + assert(c->ip - c->look - m_off + m_len < c->ip); + assert(lzo_memcmp(c->ip - c->look, c->ip - c->look - m_off, + m_len) == 0); + + if (lit > 0) + { + /* we have a current literal run: do not try a lazy match, + if the literal could be coded into a r1 or m3 match */ + if (lit == 1 && c->r1_m_len == M2_MIN_LEN) + lazy_match_min_gain = -1; + else if (lit == 3 && op == c->m3) + lazy_match_min_gain = -1; + else if (lit < 3 && op == c->m3) + lazy_match_min_gain = 0; + else + lazy_match_min_gain = 1; + +#if (M2_MIN_LEN == 2) + if (m_len == 2) + { + /* don't code a match of len 2 if we have to + code a literal run. Code a literal instead. */ + m_len = 0; + } +#endif +#if (M2_MIN_LEN == M3_MIN_LEN) + if (m_len == M2_MIN_LEN && m_off > M2_MAX_OFFSET) + { + /* don't code a M3 match of len 3 if we have to + code a literal run. Code a literal instead. */ + m_len = 0; + } +#endif + } + else + { + /* no current literal run: only try a lazy match, + if the literal could be coded into a r1 or m3 match */ + if (c->r1_m_len == M2_MIN_LEN || op == c->m3) + lazy_match_min_gain = 0; + else + lazy_match_min_gain = -1; + } + } + + + /* try a lazy match */ + if (m_len == 0) + lazy_match_min_gain = -1; + if (lazy_match_min_gain >= 0 && c->look > m_len) + { + assert(m_len > 0); + + r = find_match(c,swd,1,0); + assert(r == 0); LZO_UNUSED(r); + assert(c->look > 0); + + if (m_len <= M2_MAX_LEN && m_off <= M2_MAX_OFFSET && + c->m_off > M2_MAX_OFFSET) + lazy_match_min_gain += 1; + + if (c->m_len >= m_len + lazy_match_min_gain) + { + c->lazy++; +#if !defined(NDEBUG) + m_len = c->m_len; + m_off = c->m_off; + assert(lzo_memcmp(c->ip - c->look, c->ip - c->look - m_off, + m_len) == 0); +#endif + lit++; + assert(ii + lit == c->ip - c->look); + continue; + } + else + { + ahead = 1; + assert(ii + lit + 1 == c->ip - c->look); + } + assert(m_len > 0); + } + assert(ii + lit + ahead == c->ip - c->look); + + + if (m_len == 0) + { + /* a literal */ + lit++; + r = find_match(c,swd,1,0); + assert(r == 0); LZO_UNUSED(r); + } + else + { + /* 1 - store run */ + if (lit > 0) + { + /* code current literal run */ + if (lit == 1 && c->r1_m_len == M2_MIN_LEN) + { + /* Code a context sensitive R1 match. */ + assert((op[-2] >> M2O_BITS) == (M2_MARKER >> M2O_BITS)); + op[-2] &= M2O_MASK; + assert((op[-2] >> M2O_BITS) == 0); + /* copy 1 literal */ + *op++ = *ii++; + assert(ii + ahead == c->ip - c->look); + c->r1_r++; + } + else if (lit < 4 && op == c->m3) + { + assert((c->m3[-2] >> M3O_BITS) == 0); + c->m3[-2] |= LZO_BYTE(lit << M3O_BITS); + MEMCPY_DS(op, ii, lit); + assert(ii + ahead == c->ip - c->look); + c->m3_r++; + } + else + { + op = STORE_RUN(op,ii,lit); + } + if (lit < R0FAST) + c->r1_m_len = m_len; + else + c->r1_m_len = 0; + lit = 0; + } + else + c->r1_m_len = 0; + + /* 2 - code match */ + op = code_match(c,op,m_len,m_off); + r = find_match(c,swd,m_len,1+ahead); + assert(r == 0); LZO_UNUSED(r); + } + + c->codesize = pd(op, out); + } + + + /* store final run */ + if (lit > 0) + op = STORE_RUN(op,ii,lit); + +#if defined(LZO_EOF_CODE) + *op++ = M3_MARKER | 1; + *op++ = 0; + *op++ = 0; +#endif + + c->codesize = pd(op, out); + assert(c->textsize == in_len); + + *out_len = pd(op, out); + + if (c->cb && c->cb->nprogress) + (*c->cb->nprogress)(c->cb, c->textsize, c->codesize, 0); + +#if 0 + printf("%ld %ld -> %ld: %ld %ld %ld %ld %ld\n", + (long) c->textsize, (long)in_len, (long) c->codesize, + c->r1_r, c->m3_r, c->m2_m, c->m3_m, c->lazy); +#endif + return LZO_E_OK; +} + + + +/*********************************************************************** +// +************************************************************************/ + +LZO_PUBLIC(int) +lzo1c_999_compress ( const lzo_bytep in , lzo_uint in_len, + lzo_bytep out, lzo_uintp out_len, + lzo_voidp wrkmem ) +{ + return lzo1c_999_compress_callback(in,in_len,out,out_len,wrkmem, + (lzo_callback_p) 0, 0); +} + + +/* +vi:ts=4:et +*/ + |