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Diffstat (limited to 'src/lzo1x_d.ch')
| -rw-r--r-- | src/lzo1x_d.ch | 496 |
1 files changed, 496 insertions, 0 deletions
diff --git a/src/lzo1x_d.ch b/src/lzo1x_d.ch new file mode 100644 index 0000000..49cf326 --- /dev/null +++ b/src/lzo1x_d.ch @@ -0,0 +1,496 @@ +/* lzo1x_d.ch -- implementation of the LZO1X 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. +************************************************************************/ + +#if defined(DO_DECOMPRESS) +LZO_PUBLIC(int) +DO_DECOMPRESS ( const lzo_bytep in , lzo_uint in_len, + lzo_bytep out, lzo_uintp out_len, + lzo_voidp wrkmem ) +#endif +{ + register lzo_bytep op; + register const lzo_bytep ip; + register lzo_uint t; +#if defined(COPY_DICT) + lzo_uint m_off; + const lzo_bytep dict_end; +#else + register const lzo_bytep m_pos; +#endif + + const lzo_bytep const ip_end = in + in_len; +#if defined(HAVE_ANY_OP) + lzo_bytep const op_end = out + *out_len; +#endif +#if defined(LZO1Z) + lzo_uint last_m_off = 0; +#endif + + LZO_UNUSED(wrkmem); + +#if defined(COPY_DICT) + if (dict) + { + if (dict_len > M4_MAX_OFFSET) + { + dict += dict_len - M4_MAX_OFFSET; + dict_len = M4_MAX_OFFSET; + } + dict_end = dict + dict_len; + } + else + { + dict_len = 0; + dict_end = NULL; + } +#endif /* COPY_DICT */ + + *out_len = 0; + + op = out; + ip = in; + + if (*ip > 17) + { + t = *ip++ - 17; + if (t < 4) + goto match_next; + assert(t > 0); NEED_OP(t); NEED_IP(t+1); + do *op++ = *ip++; while (--t > 0); + goto first_literal_run; + } + + while (TEST_IP && TEST_OP) + { + t = *ip++; + if (t >= 16) + goto match; + /* a literal run */ + if (t == 0) + { + NEED_IP(1); + while (*ip == 0) + { + t += 255; + ip++; + NEED_IP(1); + } + t += 15 + *ip++; + } + /* copy literals */ + assert(t > 0); NEED_OP(t+3); NEED_IP(t+4); +#if defined(LZO_UNALIGNED_OK_8) && defined(LZO_UNALIGNED_OK_4) + t += 3; + if (t >= 8) do + { + UA_COPY64(op,ip); + op += 8; ip += 8; t -= 8; + } while (t >= 8); + if (t >= 4) + { + UA_COPY32(op,ip); + op += 4; ip += 4; t -= 4; + } + if (t > 0) + { + *op++ = *ip++; + if (t > 1) { *op++ = *ip++; if (t > 2) { *op++ = *ip++; } } + } +#elif defined(LZO_UNALIGNED_OK_4) || defined(LZO_ALIGNED_OK_4) +#if !defined(LZO_UNALIGNED_OK_4) + if (PTR_ALIGNED2_4(op,ip)) + { +#endif + UA_COPY32(op,ip); + op += 4; ip += 4; + if (--t > 0) + { + if (t >= 4) + { + do { + UA_COPY32(op,ip); + op += 4; ip += 4; t -= 4; + } while (t >= 4); + if (t > 0) do *op++ = *ip++; while (--t > 0); + } + else + do *op++ = *ip++; while (--t > 0); + } +#if !defined(LZO_UNALIGNED_OK_4) + } + else +#endif +#endif +#if !defined(LZO_UNALIGNED_OK_4) && !defined(LZO_UNALIGNED_OK_8) + { + *op++ = *ip++; *op++ = *ip++; *op++ = *ip++; + do *op++ = *ip++; while (--t > 0); + } +#endif + + +first_literal_run: + + + t = *ip++; + if (t >= 16) + goto match; +#if defined(COPY_DICT) +#if defined(LZO1Z) + m_off = (1 + M2_MAX_OFFSET) + (t << 6) + (*ip++ >> 2); + last_m_off = m_off; +#else + m_off = (1 + M2_MAX_OFFSET) + (t >> 2) + (*ip++ << 2); +#endif + NEED_OP(3); + t = 3; COPY_DICT(t,m_off) +#else /* !COPY_DICT */ +#if defined(LZO1Z) + t = (1 + M2_MAX_OFFSET) + (t << 6) + (*ip++ >> 2); + m_pos = op - t; + last_m_off = t; +#else + m_pos = op - (1 + M2_MAX_OFFSET); + m_pos -= t >> 2; + m_pos -= *ip++ << 2; +#endif + TEST_LB(m_pos); NEED_OP(3); + *op++ = *m_pos++; *op++ = *m_pos++; *op++ = *m_pos; +#endif /* COPY_DICT */ + goto match_done; + + + /* handle matches */ + do { +match: + if (t >= 64) /* a M2 match */ + { +#if defined(COPY_DICT) +#if defined(LZO1X) + m_off = 1 + ((t >> 2) & 7) + (*ip++ << 3); + t = (t >> 5) - 1; +#elif defined(LZO1Y) + m_off = 1 + ((t >> 2) & 3) + (*ip++ << 2); + t = (t >> 4) - 3; +#elif defined(LZO1Z) + m_off = t & 0x1f; + if (m_off >= 0x1c) + m_off = last_m_off; + else + { + m_off = 1 + (m_off << 6) + (*ip++ >> 2); + last_m_off = m_off; + } + t = (t >> 5) - 1; +#endif +#else /* !COPY_DICT */ +#if defined(LZO1X) + m_pos = op - 1; + m_pos -= (t >> 2) & 7; + m_pos -= *ip++ << 3; + t = (t >> 5) - 1; +#elif defined(LZO1Y) + m_pos = op - 1; + m_pos -= (t >> 2) & 3; + m_pos -= *ip++ << 2; + t = (t >> 4) - 3; +#elif defined(LZO1Z) + { + lzo_uint off = t & 0x1f; + m_pos = op; + if (off >= 0x1c) + { + assert(last_m_off > 0); + m_pos -= last_m_off; + } + else + { + off = 1 + (off << 6) + (*ip++ >> 2); + m_pos -= off; + last_m_off = off; + } + } + t = (t >> 5) - 1; +#endif + TEST_LB(m_pos); assert(t > 0); NEED_OP(t+3-1); + goto copy_match; +#endif /* COPY_DICT */ + } + else if (t >= 32) /* a M3 match */ + { + t &= 31; + if (t == 0) + { + NEED_IP(1); + while (*ip == 0) + { + t += 255; + ip++; + NEED_IP(1); + } + t += 31 + *ip++; + } +#if defined(COPY_DICT) +#if defined(LZO1Z) + m_off = 1 + (ip[0] << 6) + (ip[1] >> 2); + last_m_off = m_off; +#else + m_off = 1 + (ip[0] >> 2) + (ip[1] << 6); +#endif +#else /* !COPY_DICT */ +#if defined(LZO1Z) + { + lzo_uint off = 1 + (ip[0] << 6) + (ip[1] >> 2); + m_pos = op - off; + last_m_off = off; + } +#elif defined(LZO_UNALIGNED_OK_2) && defined(LZO_ABI_LITTLE_ENDIAN) + m_pos = op - 1; + m_pos -= UA_GET16(ip) >> 2; +#else + m_pos = op - 1; + m_pos -= (ip[0] >> 2) + (ip[1] << 6); +#endif +#endif /* COPY_DICT */ + ip += 2; + } + else if (t >= 16) /* a M4 match */ + { +#if defined(COPY_DICT) + m_off = (t & 8) << 11; +#else /* !COPY_DICT */ + m_pos = op; + m_pos -= (t & 8) << 11; +#endif /* COPY_DICT */ + t &= 7; + if (t == 0) + { + NEED_IP(1); + while (*ip == 0) + { + t += 255; + ip++; + NEED_IP(1); + } + t += 7 + *ip++; + } +#if defined(COPY_DICT) +#if defined(LZO1Z) + m_off += (ip[0] << 6) + (ip[1] >> 2); +#else + m_off += (ip[0] >> 2) + (ip[1] << 6); +#endif + ip += 2; + if (m_off == 0) + goto eof_found; + m_off += 0x4000; +#if defined(LZO1Z) + last_m_off = m_off; +#endif +#else /* !COPY_DICT */ +#if defined(LZO1Z) + m_pos -= (ip[0] << 6) + (ip[1] >> 2); +#elif defined(LZO_UNALIGNED_OK_2) && defined(LZO_ABI_LITTLE_ENDIAN) + m_pos -= UA_GET16(ip) >> 2; +#else + m_pos -= (ip[0] >> 2) + (ip[1] << 6); +#endif + ip += 2; + if (m_pos == op) + goto eof_found; + m_pos -= 0x4000; +#if defined(LZO1Z) + last_m_off = pd((const lzo_bytep)op, m_pos); +#endif +#endif /* COPY_DICT */ + } + else /* a M1 match */ + { +#if defined(COPY_DICT) +#if defined(LZO1Z) + m_off = 1 + (t << 6) + (*ip++ >> 2); + last_m_off = m_off; +#else + m_off = 1 + (t >> 2) + (*ip++ << 2); +#endif + NEED_OP(2); + t = 2; COPY_DICT(t,m_off) +#else /* !COPY_DICT */ +#if defined(LZO1Z) + t = 1 + (t << 6) + (*ip++ >> 2); + m_pos = op - t; + last_m_off = t; +#else + m_pos = op - 1; + m_pos -= t >> 2; + m_pos -= *ip++ << 2; +#endif + TEST_LB(m_pos); NEED_OP(2); + *op++ = *m_pos++; *op++ = *m_pos; +#endif /* COPY_DICT */ + goto match_done; + } + + /* copy match */ +#if defined(COPY_DICT) + + NEED_OP(t+3-1); + t += 3-1; COPY_DICT(t,m_off) + +#else /* !COPY_DICT */ + + TEST_LB(m_pos); assert(t > 0); NEED_OP(t+3-1); +#if defined(LZO_UNALIGNED_OK_8) && defined(LZO_UNALIGNED_OK_4) + if (op - m_pos >= 8) + { + t += (3 - 1); + if (t >= 8) do + { + UA_COPY64(op,m_pos); + op += 8; m_pos += 8; t -= 8; + } while (t >= 8); + if (t >= 4) + { + UA_COPY32(op,m_pos); + op += 4; m_pos += 4; t -= 4; + } + if (t > 0) + { + *op++ = m_pos[0]; + if (t > 1) { *op++ = m_pos[1]; if (t > 2) { *op++ = m_pos[2]; } } + } + } + else +#elif defined(LZO_UNALIGNED_OK_4) || defined(LZO_ALIGNED_OK_4) +#if !defined(LZO_UNALIGNED_OK_4) + if (t >= 2 * 4 - (3 - 1) && PTR_ALIGNED2_4(op,m_pos)) + { + assert((op - m_pos) >= 4); /* both pointers are aligned */ +#else + if (t >= 2 * 4 - (3 - 1) && (op - m_pos) >= 4) + { +#endif + UA_COPY32(op,m_pos); + op += 4; m_pos += 4; t -= 4 - (3 - 1); + do { + UA_COPY32(op,m_pos); + op += 4; m_pos += 4; t -= 4; + } while (t >= 4); + if (t > 0) do *op++ = *m_pos++; while (--t > 0); + } + else +#endif + { +copy_match: + *op++ = *m_pos++; *op++ = *m_pos++; + do *op++ = *m_pos++; while (--t > 0); + } + +#endif /* COPY_DICT */ + +match_done: +#if defined(LZO1Z) + t = ip[-1] & 3; +#else + t = ip[-2] & 3; +#endif + if (t == 0) + break; + + /* copy literals */ +match_next: + assert(t > 0); assert(t < 4); NEED_OP(t); NEED_IP(t+1); +#if 0 + do *op++ = *ip++; while (--t > 0); +#else + *op++ = *ip++; + if (t > 1) { *op++ = *ip++; if (t > 2) { *op++ = *ip++; } } +#endif + t = *ip++; + } while (TEST_IP && TEST_OP); + } + +#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); + *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 +*/ + |