Esempio n. 1
0
static int
do_compress    ( const lzo_bytep in , lzo_uint  in_len,
                       lzo_bytep out, lzo_uintp out_len,
                       lzo_voidp wrkmem )
{
    const lzo_bytep ip;
#if defined(__LZO_HASH_INCREMENTAL)
    lzo_xint dv;
#endif
    lzo_bytep op;
    const lzo_bytep m_pos;
    const lzo_bytep const ip_end = in+in_len - DVAL_LEN - MIN_MATCH_LONG;
    const lzo_bytep const in_end = in+in_len - DVAL_LEN;
    const lzo_bytep ii;
    lzo_dict_p const dict = (lzo_dict_p) wrkmem;

#if !defined(NDEBUG)
    const lzo_bytep m_pos_sav;
#endif

    op = out;
    ip = in;
    ii = ip;                /* point to start of literal run */
    if (in_len <= MIN_MATCH_LONG + DVAL_LEN + 1)
        goto the_end;

    /* init dictionary */
#if (LZO_DETERMINISTIC)
    BZERO8_PTR(wrkmem,sizeof(lzo_dict_t),D_SIZE);
#endif

    DVAL_FIRST(dv,ip);
    UPDATE_D(dict,0,dv,ip,in);
    ip++;
    DVAL_NEXT(dv,ip);

    do {
        LZO_DEFINE_UNINITIALIZED_VAR(lzo_uint, m_off, 0);
        lzo_uint dindex;

        DINDEX1(dindex,ip);
        GINDEX(m_pos,m_off,dict,dindex,in);
        if (LZO_CHECK_MPOS(m_pos,m_off,in,ip,MAX_OFFSET))
            goto literal;
        if (m_pos[0] == ip[0] && m_pos[1] == ip[1] && m_pos[2] == ip[2])
            goto match;
        DINDEX2(dindex,ip);
        GINDEX(m_pos,m_off,dict,dindex,in);
        if (LZO_CHECK_MPOS(m_pos,m_off,in,ip,MAX_OFFSET))
            goto literal;
        if (m_pos[0] == ip[0] && m_pos[1] == ip[1] && m_pos[2] == ip[2])
            goto match;
        goto literal;


literal:
        UPDATE_I(dict,0,dindex,ip,in);
        if (++ip >= ip_end)
            break;
        continue;

match:
        UPDATE_I(dict,0,dindex,ip,in);
#if !defined(NDEBUG) && (LZO_DICT_USE_PTR)
        m_pos_sav = m_pos;
#endif
        m_pos += 3;
        {
    /* we have found a match (of at least length 3) */
#if !defined(NDEBUG) && !(LZO_DICT_USE_PTR)
            assert((m_pos_sav = ip - m_off) == (m_pos - 3));
#endif
            /* 1) store the current literal run */
            if (pd(ip,ii) > 0)
            {
                lzo_uint t = pd(ip,ii);
#if 1
                /* OPTIMIZED: inline the copying of a short run */
                if (t < R0MIN)
                {
                    *op++ = LZO_BYTE(t);
                    MEMCPY_DS(op, ii, t);
                }
                else
#endif
                    op = store_run(op,ii,t);
            }

            /* 2a) compute match len */
            ii = ip;        /* point to start of current match */

            /* we already matched MIN_MATCH bytes,
             * m_pos also already advanced MIN_MATCH bytes */
            ip += MIN_MATCH;
            assert(m_pos < ip);

            /* try to match another MIN_MATCH_LONG - MIN_MATCH bytes
             * to see if we get a long match */

#define PS  *m_pos++ != *ip++

#if (MIN_MATCH_LONG - MIN_MATCH == 2)                   /* MBITS == 2 */
            if (PS || PS)
#elif (MIN_MATCH_LONG - MIN_MATCH == 6)                 /* MBITS == 3 */
            if (PS || PS || PS || PS || PS || PS)
#elif (MIN_MATCH_LONG - MIN_MATCH == 14)                /* MBITS == 4 */
            if (PS || PS || PS || PS || PS || PS || PS ||
                PS || PS || PS || PS || PS || PS || PS)
#elif (MIN_MATCH_LONG - MIN_MATCH == 30)                /* MBITS == 5 */
            if (PS || PS || PS || PS || PS || PS || PS || PS ||
                PS || PS || PS || PS || PS || PS || PS || PS ||
                PS || PS || PS || PS || PS || PS || PS || PS ||
                PS || PS || PS || PS || PS || PS)
#else
#  error "MBITS not yet implemented"
#endif
            {
                lzo_uint m_len;

            /* 2b) code a short match */
                    assert(pd(ip,m_pos) == m_off);
                --ip;   /* ran one too far, point back to non-match */
                m_len = pd(ip, ii);
                    assert(m_len >= MIN_MATCH_SHORT);
                    assert(m_len <= MAX_MATCH_SHORT);
                    assert(m_off > 0);
                    assert(m_off <= MAX_OFFSET);
                    assert(ii-m_off == m_pos_sav);
                    assert(lzo_memcmp(m_pos_sav,ii,m_len) == 0);
                --m_off;
                /* code short match len + low offset bits */
                *op++ = LZO_BYTE(((m_len - THRESHOLD) << OBITS) |
                                 (m_off & OMASK));
                /* code high offset bits */
                *op++ = LZO_BYTE(m_off >> OBITS);


            /* 2c) Insert phrases (beginning with ii+1) into the dictionary. */

#define SI      /* nothing */
#define DI      ++ii; DVAL_NEXT(dv,ii); UPDATE_D(dict,0,dv,ii,in);
#define XI      assert(ii < ip); ii = ip; DVAL_FIRST(dv,(ip));

#if (CLEVEL == 9) || (CLEVEL >= 7 && MBITS <= 4) || (CLEVEL >= 5 && MBITS <= 3)
            /* Insert the whole match (ii+1)..(ip-1) into dictionary.  */
                ++ii;
                do {
                    DVAL_NEXT(dv,ii);
                    UPDATE_D(dict,0,dv,ii,in);
                } while (++ii < ip);
                DVAL_NEXT(dv,ii);
                assert(ii == ip);
                DVAL_ASSERT(dv,ip);
#elif (CLEVEL >= 3)
                SI   DI DI   XI
#elif (CLEVEL >= 2)
                SI   DI      XI
#else
                             XI
#endif

            }
            else
            {
            /* we've found a long match - see how far we can still go */
                const lzo_bytep end;
                lzo_uint m_len;

                assert(ip <= in_end);
                assert(ii == ip - MIN_MATCH_LONG);

                if (pd(in_end,ip) <= (MAX_MATCH_LONG - MIN_MATCH_LONG))
                    end = in_end;
                else
                {
                    end = ip + (MAX_MATCH_LONG - MIN_MATCH_LONG);
                    assert(end < in_end);
                }

                while (ip < end  &&  *m_pos == *ip)
                    m_pos++, ip++;
                assert(ip <= in_end);

            /* 2b) code the long match */
                m_len = pd(ip, ii);
                    assert(m_len >= MIN_MATCH_LONG);
                    assert(m_len <= MAX_MATCH_LONG);
                    assert(m_off > 0);
                    assert(m_off <= MAX_OFFSET);
                    assert(ii-m_off == m_pos_sav);
                    assert(lzo_memcmp(m_pos_sav,ii,m_len) == 0);
                    assert(pd(ip,m_pos) == m_off);
                --m_off;
                /* code long match flag + low offset bits */
                *op++ = LZO_BYTE(((MSIZE - 1) << OBITS) | (m_off & OMASK));
                /* code high offset bits */
                *op++ = LZO_BYTE(m_off >> OBITS);
                /* code match len */
                *op++ = LZO_BYTE(m_len - MIN_MATCH_LONG);


            /* 2c) Insert phrases (beginning with ii+1) into the dictionary. */
#if (CLEVEL == 9)
            /* Insert the whole match (ii+1)..(ip-1) into dictionary.  */
            /* This is not recommended because it is slow. */
                ++ii;
                do {
                    DVAL_NEXT(dv,ii);
                    UPDATE_D(dict,0,dv,ii,in);
                } while (++ii < ip);
                DVAL_NEXT(dv,ii);
                assert(ii == ip);
                DVAL_ASSERT(dv,ip);
#elif (CLEVEL >= 8)
                SI   DI DI DI DI DI DI DI DI   XI
#elif (CLEVEL >= 7)
                SI   DI DI DI DI DI DI DI      XI
#elif (CLEVEL >= 6)
                SI   DI DI DI DI DI DI         XI
#elif (CLEVEL >= 5)
                SI   DI DI DI DI               XI
#elif (CLEVEL >= 4)
                SI   DI DI DI                  XI
#elif (CLEVEL >= 3)
                SI   DI DI                     XI
#elif (CLEVEL >= 2)
                SI   DI                        XI
#else
                                               XI
#endif
            }

            /* ii now points to the start of next literal run */
            assert(ii == ip);
        }
Esempio n. 2
0
static
int do_compress          ( const lzo_byte *in , lzo_uint  in_len,
                                 lzo_byte *out, lzo_uint *out_len,
                                 lzo_voidp wrkmem )
{
#if 1 && defined(__GNUC__) && defined(__i386__)
	register const lzo_byte *ip __asm__("%esi");
#else
	register const lzo_byte *ip;
#endif
	lzo_uint32 dv;
	lzo_byte *op;
	const lzo_byte * const in_end = in + in_len;
	const lzo_byte * const ip_end = in + in_len - 9;
	const lzo_byte *ii;
	const lzo_bytepp const dict = (const lzo_bytepp) wrkmem;

	op = out;
	ip = in;
	ii = ip;

	DVAL_FIRST(dv,ip);
	UPDATE_D(dict,cycle,dv,ip);
	ip++;
	DVAL_NEXT(dv,ip);


	while (1)
	{
#if 1 && defined(__GNUC__) && defined(__i386__)
		register const lzo_byte *m_pos __asm__("%edi");
#else
		register const lzo_byte *m_pos;
#endif
		lzo_uint m_len;
		lzo_ptrdiff_t m_off;
		lzo_uint lit;

		{
			lzo_uint dindex = DINDEX(dv,ip);
			m_pos = dict[dindex];
			UPDATE_I(dict,cycle,dindex,ip);
		}


		if (LZO_CHECK_MPOS_NON_DET(m_pos,m_off,in,ip,M3_MAX_OFFSET))
		{
		}
#if defined(LZO_UNALIGNED_OK_2)
		else if (* (lzo_ushortp) m_pos != * (lzo_ushortp) ip)
#else
		else if (m_pos[0] != ip[0] || m_pos[1] != ip[1]) 
#endif
		{
		}
		else
		{
			if (m_pos[2] == ip[2])
			{
				m_pos += 3;
				if (m_off <= M2_MAX_OFFSET)
					goto match;
#if 1
				if (ip - ii <= 3)
					goto match;
#else
				if (ip - ii == 3)		/* better compression, but slower */
					goto match;
#endif
				if (*m_pos == ip[3])
					goto match;
			}
		}


	/* a literal */
		++ip;
		if (ip >= ip_end)
			break;
		DVAL_NEXT(dv,ip);
		continue;


	/* a match */
match:

		/* store current literal run */
		lit = ip - ii;
		if (lit > 0)
		{
			register lzo_uint t = lit;

			if (t < 4 && op > out)
				op[-2] |= LZO_BYTE(t);
			else if (t <= 31)
				*op++ = LZO_BYTE(t);
			else
			{
				register lzo_uint tt = t - 31;

				*op++ = 0;
				while (tt > 255)
				{
					tt -= 255;
					*op++ = 0;
				}
				assert(tt > 0);
				*op++ = LZO_BYTE(tt);
			}
			do *op++ = *ii++; while (--t > 0);
		}
		assert(ii == ip);


		/* code the match */
		ip += 3;
		if (*m_pos++ != *ip++ || *m_pos++ != *ip++ || *m_pos++ != *ip++ ||
		    *m_pos++ != *ip++ || *m_pos++ != *ip++ || *m_pos++ != *ip++)
		{
			--ip;
			m_len = ip - ii;
			assert(m_len >= 3); assert(m_len <= 8);

			if (m_off <= M2_MAX_OFFSET)
			{
				m_off -= 1;
				*op++ = LZO_BYTE(((m_len - 2) << 5) | ((m_off & 7) << 2));
				*op++ = LZO_BYTE(m_off >> 3);
			}
			else if (m_len == 3 && m_off <= 2*M2_MAX_OFFSET && lit > 0)