minilzo.c

lzo-1.08-src.zip 高效的压缩解压代码

	    goto try_match;
	DINDEX2(dindex,ip);
#endif
	GINDEX(m_pos,m_off,dict,dindex,in);
	if (LZO_CHECK_MPOS_NON_DET(m_pos,m_off,in,ip,M4_MAX_OFFSET))
	    goto literal;
	if (m_off <= M2_MAX_OFFSET || m_pos[3] == ip[3])
	    goto try_match;
	goto literal;

try_match:
#if 1 && defined(LZO_UNALIGNED_OK_2)
	if (* (const lzo_ushortp) m_pos != * (const lzo_ushortp) ip)
#else
	if (m_pos[0] != ip[0] || m_pos[1] != ip[1])
#endif
	{
	}
	else
	{
	    if (m_pos[2] == ip[2])
	    {
#if 0
		if (m_off <= M2_MAX_OFFSET)
		    goto match;
		if (lit <= 3)
		    goto match;
		if (lit == 3)
		{
		    assert(op - 2 > out); op[-2] |= LZO_BYTE(3);
		    *op++ = *ii++; *op++ = *ii++; *op++ = *ii++;
		    goto code_match;
		}
		if (m_pos[3] == ip[3])
#endif
		    goto match;
	    }
	    else
	    {
#if 0
#if 0
		if (m_off <= M1_MAX_OFFSET && lit > 0 && lit <= 3)
#else
		if (m_off <= M1_MAX_OFFSET && lit == 3)
#endif
		{
		    register lzo_uint t;

		    t = lit;
		    assert(op - 2 > out); op[-2] |= LZO_BYTE(t);
		    do *op++ = *ii++; while (--t > 0);
		    assert(ii == ip);
		    m_off -= 1;
		    *op++ = LZO_BYTE(M1_MARKER | ((m_off & 3) << 2));
		    *op++ = LZO_BYTE(m_off >> 2);
		    ip += 2;
		    goto match_done;
		}
#endif
	    }
	}

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

match:
	UPDATE_I(dict,0,dindex,ip,in);
	if (pd(ip,ii) > 0)
	{
	    register lzo_uint t = pd(ip,ii);

	    if (t <= 3)
	    {
		assert(op - 2 > out);
		op[-2] |= LZO_BYTE(t);
	    }
	    else if (t <= 18)
		*op++ = LZO_BYTE(t - 3);
	    else
	    {
		register lzo_uint tt = t - 18;

		*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);
	ip += 3;
	if (m_pos[3] != *ip++ || m_pos[4] != *ip++ || m_pos[5] != *ip++ ||
	    m_pos[6] != *ip++ || m_pos[7] != *ip++ || m_pos[8] != *ip++
#ifdef LZO1Y
	    || m_pos[ 9] != *ip++ || m_pos[10] != *ip++ || m_pos[11] != *ip++
	    || m_pos[12] != *ip++ || m_pos[13] != *ip++ || m_pos[14] != *ip++
#endif
	   )
	{
	    --ip;
	    m_len = ip - ii;
	    assert(m_len >= 3); assert(m_len <= M2_MAX_LEN);

	    if (m_off <= M2_MAX_OFFSET)
	    {
		m_off -= 1;
#if defined(LZO1X)
		*op++ = LZO_BYTE(((m_len - 1) << 5) | ((m_off & 7) << 2));
		*op++ = LZO_BYTE(m_off >> 3);
#elif defined(LZO1Y)
		*op++ = LZO_BYTE(((m_len + 1) << 4) | ((m_off & 3) << 2));
		*op++ = LZO_BYTE(m_off >> 2);
#endif
	    }
	    else if (m_off <= M3_MAX_OFFSET)
	    {
		m_off -= 1;
		*op++ = LZO_BYTE(M3_MARKER | (m_len - 2));
		goto m3_m4_offset;
	    }
	    else
#if defined(LZO1X)
	    {
		m_off -= 0x4000;
		assert(m_off > 0); assert(m_off <= 0x7fff);
		*op++ = LZO_BYTE(M4_MARKER |
				 ((m_off & 0x4000) >> 11) | (m_len - 2));
		goto m3_m4_offset;
	    }
#elif defined(LZO1Y)
		goto m4_match;
#endif
	}
	else
	{
	    {
		const lzo_byte *end = in_end;
		const lzo_byte *m = m_pos + M2_MAX_LEN + 1;
		while (ip < end && *m == *ip)
		    m++, ip++;
		m_len = (ip - ii);
	    }
	    assert(m_len > M2_MAX_LEN);

	    if (m_off <= M3_MAX_OFFSET)
	    {
		m_off -= 1;
		if (m_len <= 33)
		    *op++ = LZO_BYTE(M3_MARKER | (m_len - 2));
		else
		{
		    m_len -= 33;
		    *op++ = M3_MARKER | 0;
		    goto m3_m4_len;
		}
	    }
	    else
	    {
#if defined(LZO1Y)
m4_match:
#endif
		m_off -= 0x4000;
		assert(m_off > 0); assert(m_off <= 0x7fff);
		if (m_len <= M4_MAX_LEN)
		    *op++ = LZO_BYTE(M4_MARKER |
				     ((m_off & 0x4000) >> 11) | (m_len - 2));
		else
		{
		    m_len -= M4_MAX_LEN;
		    *op++ = LZO_BYTE(M4_MARKER | ((m_off & 0x4000) >> 11));
m3_m4_len:
		    while (m_len > 255)
		    {
			m_len -= 255;
			*op++ = 0;
		    }
		    assert(m_len > 0);
		    *op++ = LZO_BYTE(m_len);
		}
	    }

m3_m4_offset:
	    *op++ = LZO_BYTE((m_off & 63) << 2);
	    *op++ = LZO_BYTE(m_off >> 6);
	}

#if 0
match_done:
#endif
	ii = ip;
	if (ip >= ip_end)
	    break;
    }

    *out_len = op - out;
    return pd(in_end,ii);
}

LZO_PUBLIC(int)
DO_COMPRESS      ( const lzo_byte *in , lzo_uint  in_len,
			 lzo_byte *out, lzo_uintp out_len,
			 lzo_voidp wrkmem )
{
    lzo_byte *op = out;
    lzo_uint t;

#if defined(__LZO_QUERY_COMPRESS)
    if (__LZO_IS_COMPRESS_QUERY(in,in_len,out,out_len,wrkmem))
	return __LZO_QUERY_COMPRESS(in,in_len,out,out_len,wrkmem,D_SIZE,lzo_sizeof(lzo_dict_t));
#endif

    if (in_len <= M2_MAX_LEN + 5)
	t = in_len;
    else
    {
	t = do_compress(in,in_len,op,out_len,wrkmem);
	op += *out_len;
    }

    if (t > 0)
    {
	const lzo_byte *ii = in + in_len - t;

	if (op == out && t <= 238)
	    *op++ = LZO_BYTE(17 + t);
	else if (t <= 3)
	    op[-2] |= LZO_BYTE(t);
	else if (t <= 18)
	    *op++ = LZO_BYTE(t - 3);
	else
	{
	    lzo_uint tt = t - 18;

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

    *op++ = M4_MARKER | 1;
    *op++ = 0;
    *op++ = 0;

    *out_len = op - out;
    return LZO_E_OK;
}

#undef do_compress
#undef DO_COMPRESS
#undef LZO_HASH

#undef LZO_TEST_DECOMPRESS_OVERRUN
#undef LZO_TEST_DECOMPRESS_OVERRUN_INPUT
#undef LZO_TEST_DECOMPRESS_OVERRUN_OUTPUT
#undef LZO_TEST_DECOMPRESS_OVERRUN_LOOKBEHIND
#undef DO_DECOMPRESS
#define DO_DECOMPRESS       lzo1x_decompress

#if defined(LZO_TEST_DECOMPRESS_OVERRUN)
#  if !defined(LZO_TEST_DECOMPRESS_OVERRUN_INPUT)
#    define LZO_TEST_DECOMPRESS_OVERRUN_INPUT       2
#  endif
#  if !defined(LZO_TEST_DECOMPRESS_OVERRUN_OUTPUT)
#    define LZO_TEST_DECOMPRESS_OVERRUN_OUTPUT      2
#  endif
#  if !defined(LZO_TEST_DECOMPRESS_OVERRUN_LOOKBEHIND)
#    define LZO_TEST_DECOMPRESS_OVERRUN_LOOKBEHIND
#  endif
#endif

#undef TEST_IP
#undef TEST_OP
#undef TEST_LOOKBEHIND
#undef NEED_IP
#undef NEED_OP
#undef HAVE_TEST_IP
#undef HAVE_TEST_OP
#undef HAVE_NEED_IP
#undef HAVE_NEED_OP
#undef HAVE_ANY_IP
#undef HAVE_ANY_OP

#if defined(LZO_TEST_DECOMPRESS_OVERRUN_INPUT)
#  if (LZO_TEST_DECOMPRESS_OVERRUN_INPUT >= 1)
#    define TEST_IP             (ip < ip_end)
#  endif
#  if (LZO_TEST_DECOMPRESS_OVERRUN_INPUT >= 2)
#    define NEED_IP(x) \
	    if ((lzo_uint)(ip_end - ip) < (lzo_uint)(x))  goto input_overrun
#  endif
#endif

#if defined(LZO_TEST_DECOMPRESS_OVERRUN_OUTPUT)
#  if (LZO_TEST_DECOMPRESS_OVERRUN_OUTPUT >= 1)
#    define TEST_OP             (op <= op_end)
#  endif
#  if (LZO_TEST_DECOMPRESS_OVERRUN_OUTPUT >= 2)
#    undef TEST_OP
#    define NEED_OP(x) \
	    if ((lzo_uint)(op_end - op) < (lzo_uint)(x))  goto output_overrun
#  endif
#endif

#if defined(LZO_TEST_DECOMPRESS_OVERRUN_LOOKBEHIND)
#  define TEST_LOOKBEHIND(m_pos,out)    if (m_pos < out) goto lookbehind_overrun
#else
#  define TEST_LOOKBEHIND(m_pos,op)     ((void) 0)
#endif

#if !defined(LZO_EOF_CODE) && !defined(TEST_IP)
#  define TEST_IP               (ip < ip_end)
#endif

#if defined(TEST_IP)
#  define HAVE_TEST_IP
#else
#  define TEST_IP               1
#endif
#if defined(TEST_OP)
#  define HAVE_TEST_OP
#else
#  define TEST_OP               1
#endif

#if defined(NEED_IP)
#  define HAVE_NEED_IP
#else
#  define NEED_IP(x)            ((void) 0)
#endif
#if defined(NEED_OP)
#  define HAVE_NEED_OP
#else
#  define NEED_OP(x)            ((void) 0)
#endif

#if defined(HAVE_TEST_IP) || defined(HAVE_NEED_IP)
#  define HAVE_ANY_IP
#endif
#if defined(HAVE_TEST_OP) || defined(HAVE_NEED_OP)
#  define HAVE_ANY_OP
#endif

#undef __COPY4
#define __COPY4(dst,src)    * (lzo_uint32p)(dst) = * (const lzo_uint32p)(src)

#undef COPY4
#if defined(LZO_UNALIGNED_OK_4)
#  define COPY4(dst,src)    __COPY4(dst,src)
#elif defined(LZO_ALIGNED_OK_4)
#  define COPY4(dst,src)    __COPY4((lzo_ptr_t)(dst),(lzo_ptr_t)(src))
#endif

#if defined(DO_DECOMPRESS)
LZO_PUBLIC(int)
DO_DECOMPRESS  ( const lzo_byte *in , lzo_uint  in_len,
		       lzo_byte *out, lzo_uintp out_len,
		       lzo_voidp wrkmem )
#endif
{
    register lzo_byte *op;
    register const lzo_byte *ip;
    register lzo_uint t;
#if defined(COPY_DICT)
    lzo_uint m_off;
    const lzo_byte *dict_end;
#else
    register const lzo_byte *m_pos;
#endif

    const lzo_byte * const ip_end = in + in_len;
#if defined(HAVE_ANY_OP)
    lzo_byte * const op_end = out + *out_len;
#endif
#if defined(LZO1Z)
    lzo_uint last_m_off = 0;
#endif

    LZO_UNUSED(wrkmem);

#if defined(__LZO_QUERY_DECOMPRESS)
    if (__LZO_IS_DECOMPRESS_QUERY(in,in_len,out,out_len,wrkmem))
	return __LZO_QUERY_DECOMPRESS(in,in_len,out,out_len,wrkmem,0,0);
#endif

#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

    *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;
	if (t == 0)
	{
	    NEED_IP(1);
	    while (*ip == 0)
	    {
		t += 255;
		ip++;
		NEED_IP(1);
	    }
	    t += 15 + *ip++;
	}
	assert(t > 0); NEED_OP(t+3); NEED_IP(t+4);
#if defined(LZO_UNALIGNED_OK_4) || defined(LZO_ALIGNED_OK_4)
#if !defined(LZO_UNALIGNED_OK_4)
	if (PTR_ALIGNED2_4(op,ip))
	{
#endif
	COPY4(op,ip);
	op += 4; ip += 4;
	if (--t > 0)
	{
	    if (t >= 4)
	    {
		do {
		    COPY4(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)
	{
	    *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
#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_LOOKBEHIND(m_pos,out); NEED_OP(3);
	*op++ = *m_pos++; *op++ = *m_pos++; *op++ = *m_pos;
#endif
	goto match_done;

	while (TEST_IP && TEST_OP)
	{
match:
	    if (t >= 64)
	    {
#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
#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;