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Diffstat (limited to 'src/lzo1x_oo.ch')
| -rw-r--r-- | src/lzo1x_oo.ch | 369 |
1 files changed, 369 insertions, 0 deletions
diff --git a/src/lzo1x_oo.ch b/src/lzo1x_oo.ch new file mode 100644 index 0000000..6bd2cf1 --- /dev/null +++ b/src/lzo1x_oo.ch @@ -0,0 +1,369 @@ +/* lzo1x_oo.ch -- LZO1X compressed data optimizer + + 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/ + */ + + +#define TEST_IP (ip < ip_end) +#define TEST_OP (op <= op_end) + +#define NO_LIT LZO_UINT_MAX + + +/*********************************************************************** +// +************************************************************************/ + +static void copy2(lzo_bytep ip, const lzo_bytep m_pos, lzo_uint off) +{ + assert(off > 0); + ip[0] = m_pos[0]; + if (off == 1) + ip[1] = m_pos[0]; + else + ip[1] = m_pos[1]; +} + + +static void copy3(lzo_bytep ip, const lzo_bytep m_pos, lzo_uint off) +{ + assert(off > 0); + ip[0] = m_pos[0]; + if (off == 1) + { + ip[2] = ip[1] = m_pos[0]; + } + else if (off == 2) + { + ip[1] = m_pos[1]; + ip[2] = m_pos[0]; + } + else + { + ip[1] = m_pos[1]; + ip[2] = m_pos[2]; + } +} + + +/*********************************************************************** +// optimize a block of data. +************************************************************************/ + +LZO_PUBLIC(int) +DO_OPTIMIZE ( lzo_bytep in , lzo_uint in_len, + lzo_bytep out, lzo_uintp out_len, + lzo_voidp wrkmem ) +{ + lzo_bytep op; + lzo_bytep ip; + lzo_uint t; + lzo_bytep m_pos; + lzo_bytep const ip_end = in + in_len; + lzo_bytep const op_end = out + *out_len; + lzo_bytep litp = NULL; + lzo_uint lit = 0; + lzo_uint next_lit = NO_LIT; + lzo_uint nl; + unsigned long o_m1_a = 0, o_m1_b = 0, o_m2 = 0, o_m3_a = 0, o_m3_b = 0; + + LZO_UNUSED(wrkmem); + + *out_len = 0; + + op = out; + ip = in; + + assert(in_len >= 3); + if (*ip > 17) + { + t = *ip++ - 17; + if (t < 4) + goto match_next; + goto first_literal_run; + } + assert(*ip < 16 || (*ip == 17 && in_len == 3)); + + while (TEST_IP && TEST_OP) + { + t = *ip++; + if (t >= 16) + goto match; + /* a literal run */ + litp = ip - 1; + if (t == 0) + { + t = 15; + while (*ip == 0) + t += 255, ip++; + t += *ip++; + } + lit = t + 3; + /* copy literals */ +copy_literal_run: + *op++ = *ip++; *op++ = *ip++; *op++ = *ip++; +first_literal_run: + do *op++ = *ip++; while (--t > 0); + + + t = *ip++; + + if (t >= 16) + goto match; +#if defined(LZO1X) + m_pos = op - 1 - 0x800; +#elif defined(LZO1Y) + m_pos = op - 1 - 0x400; +#endif + m_pos -= t >> 2; + m_pos -= *ip++ << 2; + *op++ = *m_pos++; *op++ = *m_pos++; *op++ = *m_pos++; + lit = 0; + goto match_done; + + + /* handle matches */ + do { + if (t < 16) /* a M1 match */ + { + m_pos = op - 1; + m_pos -= t >> 2; + m_pos -= *ip++ << 2; + + if (litp == NULL) + goto copy_m1; + + /* assert that there was a match just before */ + assert(lit >= 1 && lit <= 3); + assert(litp == ip - 2 - lit - 2); + assert((lzo_uint)(*litp & 3) == lit); + nl = ip[-2] & 3; + /* test if a match follows */ + if (nl == 0 && lit == 1 && ip[0] >= 16) + { + next_lit = nl; + /* adjust length of previous short run */ + lit += 2; + *litp = LZO_BYTE((*litp & ~3) | lit); + /* copy over the 2 literals that replace the match */ + copy2(ip-2,m_pos,pd(op,m_pos)); + o_m1_a++; + } + /* test if a literal run follows */ + else if (nl == 0 && ip[0] < 16 && ip[0] != 0 && + (lit + 2 + ip[0] < 16)) + { + t = *ip++; + /* remove short run */ + *litp &= ~3; + /* copy over the 2 literals that replace the match */ + copy2(ip-3+1,m_pos,pd(op,m_pos)); + /* move literals 1 byte ahead */ + litp += 2; + if (lit > 0) + lzo_memmove(litp+1,litp,lit); + /* insert new length of long literal run */ + lit += 2 + t + 3; assert(lit <= 18); + *litp = LZO_BYTE(lit - 3); + + o_m1_b++; + *op++ = *m_pos++; *op++ = *m_pos++; + goto copy_literal_run; + } +copy_m1: + *op++ = *m_pos++; *op++ = *m_pos++; + } + else + { +match: + if (t >= 64) /* a M2 match */ + { + m_pos = op - 1; +#if defined(LZO1X) + m_pos -= (t >> 2) & 7; + m_pos -= *ip++ << 3; + t = (t >> 5) - 1; +#elif defined(LZO1Y) + m_pos -= (t >> 2) & 3; + m_pos -= *ip++ << 2; + t = (t >> 4) - 3; +#endif + if (litp == NULL) + goto copy_m; + + nl = ip[-2] & 3; + /* test if in beetween two long literal runs */ + if (t == 1 && lit > 3 && nl == 0 && + ip[0] < 16 && ip[0] != 0 && (lit + 3 + ip[0] < 16)) + { + assert(*litp == lit - 3); + t = *ip++; + /* copy over the 3 literals that replace the match */ + copy3(ip-1-2,m_pos,pd(op,m_pos)); + /* set new length of previous literal run */ + lit += 3 + t + 3; assert(lit <= 18); + *litp = LZO_BYTE(lit - 3); + o_m2++; + *op++ = *m_pos++; *op++ = *m_pos++; *op++ = *m_pos++; + goto copy_literal_run; + } + } + else + { + if (t >= 32) /* a M3 match */ + { + t &= 31; + if (t == 0) + { + t = 31; + while (*ip == 0) + t += 255, ip++; + t += *ip++; + } + m_pos = op - 1; + m_pos -= *ip++ >> 2; + m_pos -= *ip++ << 6; + } + else /* a M4 match */ + { + m_pos = op; + m_pos -= (t & 8) << 11; + t &= 7; + if (t == 0) + { + t = 7; + while (*ip == 0) + t += 255, ip++; + t += *ip++; + } + m_pos -= *ip++ >> 2; + m_pos -= *ip++ << 6; + if (m_pos == op) + goto eof_found; + m_pos -= 0x4000; + } + if (litp == NULL) + goto copy_m; + + nl = ip[-2] & 3; + /* test if in beetween two matches */ + if (t == 1 && lit == 0 && nl == 0 && ip[0] >= 16) + { + assert(litp == ip - 3 - lit - 2); + assert((lzo_uint)(*litp & 3) == lit); + next_lit = nl; + /* make a previous short run */ + lit += 3; + *litp = LZO_BYTE((*litp & ~3) | lit); + /* copy over the 3 literals that replace the match */ + copy3(ip-3,m_pos,pd(op,m_pos)); + o_m3_a++; + } + /* test if a literal run follows */ + else if (t == 1 && lit <= 3 && nl == 0 && + ip[0] < 16 && ip[0] != 0 && (lit + 3 + ip[0] < 16)) + { + assert(litp == ip - 3 - lit - 2); + assert((lzo_uint)(*litp & 3) == lit); + t = *ip++; + /* remove short run */ + *litp &= ~3; + /* copy over the 3 literals that replace the match */ + copy3(ip-4+1,m_pos,pd(op,m_pos)); + /* move literals 1 byte ahead */ + litp += 2; + if (lit > 0) + lzo_memmove(litp+1,litp,lit); + /* insert new length of long literal run */ + lit += 3 + t + 3; assert(lit <= 18); + *litp = LZO_BYTE(lit - 3); + + o_m3_b++; + *op++ = *m_pos++; *op++ = *m_pos++; *op++ = *m_pos++; + goto copy_literal_run; + } + } +copy_m: + *op++ = *m_pos++; *op++ = *m_pos++; + do *op++ = *m_pos++; while (--t > 0); + } + +match_done: + if (next_lit == NO_LIT) + { + t = ip[-2] & 3; + lit = t; + litp = ip - 2; + } + else + t = next_lit; + assert(t <= 3); + next_lit = NO_LIT; + if (t == 0) + break; + /* copy literals */ +match_next: + do *op++ = *ip++; while (--t > 0); + t = *ip++; + } while (TEST_IP && TEST_OP); + } + + /* no EOF code was found */ + *out_len = pd(op, out); + return LZO_E_EOF_NOT_FOUND; + +eof_found: + assert(t == 1); +#if 0 + printf("optimize: %5lu %5lu %5lu %5lu %5lu\n", + o_m1_a, o_m1_b, o_m2, o_m3_a, o_m3_b); +#endif + LZO_UNUSED(o_m1_a); LZO_UNUSED(o_m1_b); LZO_UNUSED(o_m2); + LZO_UNUSED(o_m3_a); LZO_UNUSED(o_m3_b); + *out_len = pd(op, out); + return (ip == ip_end ? LZO_E_OK : + (ip < ip_end ? LZO_E_INPUT_NOT_CONSUMED : LZO_E_INPUT_OVERRUN)); +} + + +/* +vi:ts=4:et +*/ + |