xref: /external/syslinux/lzo/src/lzo1x_d3.c

/* lzo1x_d3.c -- LZO1X decompression with preset dictionary

   This file is part of the LZO real-time data compression library.

   Copyright (C) 1996-2014 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 "config1x.h"

#define LZO_TEST_OVERRUN 1


#define SLOW_MEMCPY(a,b,l)      { do *a++ = *b++; while (--l > 0); }
#define FAST_MEMCPY(a,b,l)      { lzo_memcpy(a,b,l); a += l; }

#if 1 && defined(FAST_MEMCPY)
#  define DICT_MEMMOVE(op,m_pos,m_len,m_off) \
        if (m_off >= (m_len)) \
            FAST_MEMCPY(op,m_pos,m_len) \
        else \
            SLOW_MEMCPY(op,m_pos,m_len)
#else
#  define DICT_MEMMOVE(op,m_pos,m_len,m_off) \
        SLOW_MEMCPY(op,m_pos,m_len)
#endif

#if !defined(FAST_MEMCPY)
#  define FAST_MEMCPY   SLOW_MEMCPY
#endif


#define COPY_DICT_DICT(m_len,m_off) \
    { \
        const lzo_bytep m_pos; \
        m_off -= pd(op, out); assert(m_off > 0); \
        if (m_off > dict_len) goto lookbehind_overrun; \
        m_pos = dict_end - m_off; \
        if (m_len > m_off) \
        { \
            m_len -= m_off; \
            FAST_MEMCPY(op,m_pos,m_off) \
            m_pos = out; \
            SLOW_MEMCPY(op,m_pos,m_len) \
        } \
        else \
            FAST_MEMCPY(op,m_pos,m_len) \
    }

#define COPY_DICT(m_len,m_off) \
    assert(m_len >= 2); assert(m_off > 0); assert(op > out); \
    if (m_off <= pd(op, out)) \
    { \
        const lzo_bytep m_pos = op - m_off; \
        DICT_MEMMOVE(op,m_pos,m_len,m_off) \
    } \
    else \
        COPY_DICT_DICT(m_len,m_off)




LZO_PUBLIC(int)
lzo1x_decompress_dict_safe ( const lzo_bytep in,  lzo_uint  in_len,
                                   lzo_bytep out, lzo_uintp out_len,
                                   lzo_voidp wrkmem /* NOT USED */,
                             const lzo_bytep dict, lzo_uint dict_len)


#include "lzo1x_d.ch"


/*
vi:ts=4:et
*/