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Diffstat (limited to 'src/lzo2a_d.ch')
| -rw-r--r-- | src/lzo2a_d.ch | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/src/lzo2a_d.ch b/src/lzo2a_d.ch new file mode 100644 index 0000000..48e51ca --- /dev/null +++ b/src/lzo2a_d.ch @@ -0,0 +1,191 @@ +/* lzo2a_d.ch -- implementation of the LZO2A decompression 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 "lzo1_d.ch" + + +/*********************************************************************** +// decompress a block of data. +************************************************************************/ + +#define _NEEDBYTE NEED_IP(1) +#define _NEXTBYTE (*ip++) + +LZO_PUBLIC(int) +DO_DECOMPRESS ( const lzo_bytep in , lzo_uint in_len, + lzo_bytep out, lzo_uintp out_len, + lzo_voidp wrkmem ) +{ + register lzo_bytep op; + register const lzo_bytep ip; + register const lzo_bytep m_pos; + + lzo_uint t; + const lzo_bytep const ip_end = in + in_len; +#if defined(HAVE_ANY_OP) + lzo_bytep const op_end = out + *out_len; +#endif + + lzo_uint32 b = 0; /* bit buffer */ + unsigned k = 0; /* bits in bit buffer */ + + LZO_UNUSED(wrkmem); + + op = out; + ip = in; + + while (TEST_IP && TEST_OP) + { + NEEDBITS(1); + if (MASKBITS(1) == 0) + { + DUMPBITS(1); + /* a literal */ + NEED_IP(1); NEED_OP(1); + *op++ = *ip++; + continue; + } + DUMPBITS(1); + + NEEDBITS(1); + if (MASKBITS(1) == 0) + { + DUMPBITS(1); + /* a M1 match */ + NEEDBITS(2); + t = M1_MIN_LEN + (lzo_uint) MASKBITS(2); + DUMPBITS(2); + NEED_IP(1); NEED_OP(t); + m_pos = op - 1 - *ip++; + assert(m_pos >= out); assert(m_pos < op); + TEST_LB(m_pos); + MEMCPY_DS(op,m_pos,t); + continue; + } + DUMPBITS(1); + + NEED_IP(2); + t = *ip++; + m_pos = op; + m_pos -= (t & 31) | (((lzo_uint) *ip++) << 5); + t >>= 5; + if (t == 0) + { +#if (SWD_N >= 8192) + NEEDBITS(1); + t = MASKBITS(1); + DUMPBITS(1); + if (t == 0) + t = 10 - 1; + else + { + /* a M3 match */ + m_pos -= 8192; /* t << 13 */ + t = M3_MIN_LEN - 1; + } +#else + t = 10 - 1; +#endif + NEED_IP(1); + while (*ip == 0) + { + t += 255; + ip++; + NEED_IP(1); + } + t += *ip++; + } + else + { +#if defined(LZO_EOF_CODE) + if (m_pos == op) + goto eof_found; +#endif + t += 2; + } + assert(m_pos >= out); assert(m_pos < op); + TEST_LB(m_pos); + NEED_OP(t); + MEMCPY_DS(op,m_pos,t); + } + + +#if defined(LZO_EOF_CODE) +#if defined(HAVE_TEST_IP) || defined(HAVE_TEST_OP) + /* no EOF code was found */ + *out_len = pd(op, out); + return LZO_E_EOF_NOT_FOUND; +#endif + +eof_found: + assert(t == 1); +#endif + *out_len = pd(op, out); + return (ip == ip_end ? LZO_E_OK : + (ip < ip_end ? LZO_E_INPUT_NOT_CONSUMED : LZO_E_INPUT_OVERRUN)); + + +#if defined(HAVE_NEED_IP) +input_overrun: + *out_len = pd(op, out); + return LZO_E_INPUT_OVERRUN; +#endif + +#if defined(HAVE_NEED_OP) +output_overrun: + *out_len = pd(op, out); + return LZO_E_OUTPUT_OVERRUN; +#endif + +#if defined(LZO_TEST_OVERRUN_LOOKBEHIND) +lookbehind_overrun: + *out_len = pd(op, out); + return LZO_E_LOOKBEHIND_OVERRUN; +#endif +} + + +/* +vi:ts=4:et +*/ + |