404 lines
12 KiB
Plaintext
404 lines
12 KiB
Plaintext
/* lzo1x_c.ch -- implementation of the LZO1[XY]-1 compression algorithm
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This file is part of the LZO real-time data compression library.
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Copyright (C) 1996-2015 Markus Franz Xaver Johannes Oberhumer
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All Rights Reserved.
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The LZO library is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License as
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published by the Free Software Foundation; either version 2 of
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the License, or (at your option) any later version.
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The LZO library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with the LZO library; see the file COPYING.
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If not, write to the Free Software Foundation, Inc.,
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51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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Markus F.X.J. Oberhumer
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<markus@oberhumer.com>
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http://www.oberhumer.com/opensource/lzo/
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*/
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#if 1 && defined(DO_COMPRESS) && !defined(do_compress)
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/* choose a unique name to better help PGO optimizations */
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# define do_compress LZO_PP_ECONCAT2(DO_COMPRESS,_core)
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#endif
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/***********************************************************************
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// compress a block of data.
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************************************************************************/
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static __lzo_noinline lzo_uint
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do_compress ( const lzo_bytep in , lzo_uint in_len,
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lzo_bytep out, lzo_uintp out_len,
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lzo_uint ti, lzo_voidp wrkmem)
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{
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const lzo_bytep ip;
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lzo_bytep op;
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const lzo_bytep const in_end = in + in_len;
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const lzo_bytep const ip_end = in + in_len - 20;
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const lzo_bytep ii;
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lzo_dict_p const dict = (lzo_dict_p) wrkmem;
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op = out;
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ip = in;
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ii = ip;
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ip += ti < 4 ? 4 - ti : 0;
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for (;;)
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{
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const lzo_bytep m_pos;
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#if !(LZO_DETERMINISTIC)
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LZO_DEFINE_UNINITIALIZED_VAR(lzo_uint, m_off, 0);
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lzo_uint m_len;
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lzo_uint dindex;
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next:
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if __lzo_unlikely(ip >= ip_end)
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break;
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DINDEX1(dindex,ip);
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GINDEX(m_pos,m_off,dict,dindex,in);
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if (LZO_CHECK_MPOS_NON_DET(m_pos,m_off,in,ip,M4_MAX_OFFSET))
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goto literal;
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#if 1
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if (m_off <= M2_MAX_OFFSET || m_pos[3] == ip[3])
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goto try_match;
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DINDEX2(dindex,ip);
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#endif
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GINDEX(m_pos,m_off,dict,dindex,in);
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if (LZO_CHECK_MPOS_NON_DET(m_pos,m_off,in,ip,M4_MAX_OFFSET))
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goto literal;
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if (m_off <= M2_MAX_OFFSET || m_pos[3] == ip[3])
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goto try_match;
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goto literal;
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try_match:
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#if (LZO_OPT_UNALIGNED32)
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if (UA_GET_NE32(m_pos) != UA_GET_NE32(ip))
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#else
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if (m_pos[0] != ip[0] || m_pos[1] != ip[1] || m_pos[2] != ip[2] || m_pos[3] != ip[3])
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#endif
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{
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/* a literal */
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literal:
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UPDATE_I(dict,0,dindex,ip,in);
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ip += 1 + ((ip - ii) >> 5);
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continue;
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}
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/*match:*/
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UPDATE_I(dict,0,dindex,ip,in);
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#else
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lzo_uint m_off;
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lzo_uint m_len;
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{
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lzo_uint32_t dv;
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lzo_uint dindex;
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literal:
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ip += 1 + ((ip - ii) >> 5);
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next:
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if __lzo_unlikely(ip >= ip_end)
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break;
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dv = UA_GET_LE32(ip);
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dindex = DINDEX(dv,ip);
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GINDEX(m_off,m_pos,in+dict,dindex,in);
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UPDATE_I(dict,0,dindex,ip,in);
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if __lzo_unlikely(dv != UA_GET_LE32(m_pos))
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goto literal;
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}
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#endif
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/* a match */
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ii -= ti; ti = 0;
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{
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lzo_uint t = pd(ip,ii);
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if (t != 0)
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{
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if (t <= 3)
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{
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op[-2] = LZO_BYTE(op[-2] | t);
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#if (LZO_OPT_UNALIGNED32)
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UA_COPY4(op, ii);
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op += t;
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#else
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{ do *op++ = *ii++; while (--t > 0); }
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#endif
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}
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#if (LZO_OPT_UNALIGNED32) || (LZO_OPT_UNALIGNED64)
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else if (t <= 16)
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{
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*op++ = LZO_BYTE(t - 3);
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UA_COPY8(op, ii);
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UA_COPY8(op+8, ii+8);
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op += t;
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}
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#endif
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else
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{
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if (t <= 18)
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*op++ = LZO_BYTE(t - 3);
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else
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{
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lzo_uint tt = t - 18;
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*op++ = 0;
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while __lzo_unlikely(tt > 255)
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{
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tt -= 255;
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UA_SET1(op, 0);
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op++;
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}
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assert(tt > 0);
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*op++ = LZO_BYTE(tt);
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}
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#if (LZO_OPT_UNALIGNED32) || (LZO_OPT_UNALIGNED64)
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do {
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UA_COPY8(op, ii);
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UA_COPY8(op+8, ii+8);
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op += 16; ii += 16; t -= 16;
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} while (t >= 16); if (t > 0)
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#endif
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{ do *op++ = *ii++; while (--t > 0); }
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}
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}
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}
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m_len = 4;
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{
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#if (LZO_OPT_UNALIGNED64)
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lzo_uint64_t v;
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v = UA_GET_NE64(ip + m_len) ^ UA_GET_NE64(m_pos + m_len);
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if __lzo_unlikely(v == 0) {
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do {
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m_len += 8;
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v = UA_GET_NE64(ip + m_len) ^ UA_GET_NE64(m_pos + m_len);
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if __lzo_unlikely(ip + m_len >= ip_end)
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goto m_len_done;
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} while (v == 0);
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}
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#if (LZO_ABI_BIG_ENDIAN) && defined(lzo_bitops_ctlz64)
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m_len += lzo_bitops_ctlz64(v) / CHAR_BIT;
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#elif (LZO_ABI_BIG_ENDIAN)
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if ((v >> (64 - CHAR_BIT)) == 0) do {
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v <<= CHAR_BIT;
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m_len += 1;
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} while ((v >> (64 - CHAR_BIT)) == 0);
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#elif (LZO_ABI_LITTLE_ENDIAN) && defined(lzo_bitops_cttz64)
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m_len += lzo_bitops_cttz64(v) / CHAR_BIT;
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#elif (LZO_ABI_LITTLE_ENDIAN)
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if ((v & UCHAR_MAX) == 0) do {
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v >>= CHAR_BIT;
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m_len += 1;
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} while ((v & UCHAR_MAX) == 0);
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#else
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if (ip[m_len] == m_pos[m_len]) do {
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m_len += 1;
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} while (ip[m_len] == m_pos[m_len]);
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#endif
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#elif (LZO_OPT_UNALIGNED32)
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lzo_uint32_t v;
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v = UA_GET_NE32(ip + m_len) ^ UA_GET_NE32(m_pos + m_len);
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if __lzo_unlikely(v == 0) {
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do {
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m_len += 4;
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v = UA_GET_NE32(ip + m_len) ^ UA_GET_NE32(m_pos + m_len);
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if (v != 0)
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break;
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m_len += 4;
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v = UA_GET_NE32(ip + m_len) ^ UA_GET_NE32(m_pos + m_len);
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if __lzo_unlikely(ip + m_len >= ip_end)
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goto m_len_done;
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} while (v == 0);
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}
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#if (LZO_ABI_BIG_ENDIAN) && defined(lzo_bitops_ctlz32)
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m_len += lzo_bitops_ctlz32(v) / CHAR_BIT;
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#elif (LZO_ABI_BIG_ENDIAN)
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if ((v >> (32 - CHAR_BIT)) == 0) do {
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v <<= CHAR_BIT;
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m_len += 1;
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} while ((v >> (32 - CHAR_BIT)) == 0);
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#elif (LZO_ABI_LITTLE_ENDIAN) && defined(lzo_bitops_cttz32)
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m_len += lzo_bitops_cttz32(v) / CHAR_BIT;
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#elif (LZO_ABI_LITTLE_ENDIAN)
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if ((v & UCHAR_MAX) == 0) do {
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v >>= CHAR_BIT;
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m_len += 1;
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} while ((v & UCHAR_MAX) == 0);
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#else
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if (ip[m_len] == m_pos[m_len]) do {
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m_len += 1;
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} while (ip[m_len] == m_pos[m_len]);
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#endif
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#else
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if __lzo_unlikely(ip[m_len] == m_pos[m_len]) {
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do {
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m_len += 1;
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if (ip[m_len] != m_pos[m_len])
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break;
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m_len += 1;
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if (ip[m_len] != m_pos[m_len])
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break;
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m_len += 1;
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if (ip[m_len] != m_pos[m_len])
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break;
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m_len += 1;
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if (ip[m_len] != m_pos[m_len])
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break;
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m_len += 1;
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if (ip[m_len] != m_pos[m_len])
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break;
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m_len += 1;
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if (ip[m_len] != m_pos[m_len])
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break;
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m_len += 1;
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if (ip[m_len] != m_pos[m_len])
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break;
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m_len += 1;
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if __lzo_unlikely(ip + m_len >= ip_end)
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goto m_len_done;
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} while (ip[m_len] == m_pos[m_len]);
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}
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#endif
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}
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m_len_done:
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m_off = pd(ip,m_pos);
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ip += m_len;
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ii = ip;
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if (m_len <= M2_MAX_LEN && m_off <= M2_MAX_OFFSET)
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{
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m_off -= 1;
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#if defined(LZO1X)
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*op++ = LZO_BYTE(((m_len - 1) << 5) | ((m_off & 7) << 2));
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*op++ = LZO_BYTE(m_off >> 3);
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#elif defined(LZO1Y)
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*op++ = LZO_BYTE(((m_len + 1) << 4) | ((m_off & 3) << 2));
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*op++ = LZO_BYTE(m_off >> 2);
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#endif
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}
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else if (m_off <= M3_MAX_OFFSET)
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{
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m_off -= 1;
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if (m_len <= M3_MAX_LEN)
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*op++ = LZO_BYTE(M3_MARKER | (m_len - 2));
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else
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{
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m_len -= M3_MAX_LEN;
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*op++ = M3_MARKER | 0;
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while __lzo_unlikely(m_len > 255)
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{
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m_len -= 255;
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UA_SET1(op, 0);
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op++;
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}
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*op++ = LZO_BYTE(m_len);
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}
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*op++ = LZO_BYTE(m_off << 2);
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*op++ = LZO_BYTE(m_off >> 6);
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}
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else
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{
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m_off -= 0x4000;
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if (m_len <= M4_MAX_LEN)
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*op++ = LZO_BYTE(M4_MARKER | ((m_off >> 11) & 8) | (m_len - 2));
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else
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{
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m_len -= M4_MAX_LEN;
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*op++ = LZO_BYTE(M4_MARKER | ((m_off >> 11) & 8));
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while __lzo_unlikely(m_len > 255)
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{
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m_len -= 255;
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UA_SET1(op, 0);
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op++;
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}
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*op++ = LZO_BYTE(m_len);
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}
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*op++ = LZO_BYTE(m_off << 2);
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*op++ = LZO_BYTE(m_off >> 6);
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}
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goto next;
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}
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*out_len = pd(op, out);
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return pd(in_end,ii-ti);
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}
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/***********************************************************************
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// public entry point
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************************************************************************/
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LZO_PUBLIC(int)
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DO_COMPRESS ( const lzo_bytep in , lzo_uint in_len,
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lzo_bytep out, lzo_uintp out_len,
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lzo_voidp wrkmem )
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{
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const lzo_bytep ip = in;
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lzo_bytep op = out;
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lzo_uint l = in_len;
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lzo_uint t = 0;
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while (l > 20)
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{
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lzo_uint ll = l;
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lzo_uintptr_t ll_end;
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#if 0 || (LZO_DETERMINISTIC)
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ll = LZO_MIN(ll, 49152);
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#endif
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ll_end = (lzo_uintptr_t)ip + ll;
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if ((ll_end + ((t + ll) >> 5)) <= ll_end || (const lzo_bytep)(ll_end + ((t + ll) >> 5)) <= ip + ll)
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break;
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#if (LZO_DETERMINISTIC)
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lzo_memset(wrkmem, 0, ((lzo_uint)1 << D_BITS) * sizeof(lzo_dict_t));
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#endif
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t = do_compress(ip,ll,op,out_len,t,wrkmem);
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ip += ll;
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op += *out_len;
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l -= ll;
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}
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t += l;
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if (t > 0)
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{
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const lzo_bytep ii = in + in_len - t;
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if (op == out && t <= 238)
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*op++ = LZO_BYTE(17 + t);
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else if (t <= 3)
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op[-2] = LZO_BYTE(op[-2] | t);
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else if (t <= 18)
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*op++ = LZO_BYTE(t - 3);
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else
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{
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lzo_uint tt = t - 18;
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*op++ = 0;
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while (tt > 255)
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{
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tt -= 255;
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UA_SET1(op, 0);
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op++;
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}
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assert(tt > 0);
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*op++ = LZO_BYTE(tt);
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}
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UA_COPYN(op, ii, t);
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op += t;
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}
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*op++ = M4_MARKER | 1;
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*op++ = 0;
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*op++ = 0;
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*out_len = pd(op, out);
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return LZO_E_OK;
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}
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/* vim:set ts=4 sw=4 et: */
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