minilzo.c

lzo-1.08-src.zip 高效的压缩解压代码

#endif
		TEST_LOOKBEHIND(m_pos,out); assert(t > 0); NEED_OP(t+3-1);
		goto copy_match;
#endif
	    }
	    else if (t >= 32)
	    {
		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
#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) && (LZO_BYTE_ORDER == LZO_LITTLE_ENDIAN)
		m_pos = op - 1;
		m_pos -= (* (const lzo_ushortp) ip) >> 2;
#else
		m_pos = op - 1;
		m_pos -= (ip[0] >> 2) + (ip[1] << 6);
#endif
#endif
		ip += 2;
	    }
	    else if (t >= 16)
	    {
#if defined(COPY_DICT)
		m_off = (t & 8) << 11;
#else
		m_pos = op;
		m_pos -= (t & 8) << 11;
#endif
		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
#if defined(LZO1Z)
		m_pos -= (ip[0] << 6) + (ip[1] >> 2);
#elif defined(LZO_UNALIGNED_OK_2) && (LZO_BYTE_ORDER == LZO_LITTLE_ENDIAN)
		m_pos -= (* (const lzo_ushortp) 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 = op - m_pos;
#endif
#endif
	    }
	    else
	    {
#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
#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_LOOKBEHIND(m_pos,out); NEED_OP(2);
		*op++ = *m_pos++; *op++ = *m_pos;
#endif
		goto match_done;
	    }

#if defined(COPY_DICT)

	    NEED_OP(t+3-1);
	    t += 3-1; COPY_DICT(t,m_off)

#else

	    TEST_LOOKBEHIND(m_pos,out); assert(t > 0); NEED_OP(t+3-1);
#if 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);
#else
	    if (t >= 2 * 4 - (3 - 1) && (op - m_pos) >= 4)
	    {
#endif
		COPY4(op,m_pos);
		op += 4; m_pos += 4; t -= 4 - (3 - 1);
		do {
		    COPY4(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

match_done:
#if defined(LZO1Z)
	    t = ip[-1] & 3;
#else
	    t = ip[-2] & 3;
#endif
	    if (t == 0)
		break;

match_next:
	    assert(t > 0); NEED_OP(t); NEED_IP(t+1);
	    do *op++ = *ip++; while (--t > 0);
	    t = *ip++;
	}
    }

#if defined(HAVE_TEST_IP) || defined(HAVE_TEST_OP)
    *out_len = op - out;
    return LZO_E_EOF_NOT_FOUND;
#endif

eof_found:
    assert(t == 1);
    *out_len = 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 = op - out;
    return LZO_E_INPUT_OVERRUN;
#endif

#if defined(HAVE_NEED_OP)
output_overrun:
    *out_len = op - out;
    return LZO_E_OUTPUT_OVERRUN;
#endif

#if defined(LZO_TEST_DECOMPRESS_OVERRUN_LOOKBEHIND)
lookbehind_overrun:
    *out_len = op - out;
    return LZO_E_LOOKBEHIND_OVERRUN;
#endif
}

#define LZO_TEST_DECOMPRESS_OVERRUN
#undef DO_DECOMPRESS
#define DO_DECOMPRESS       lzo1x_decompress_safe

#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;
#endif
		TEST_LOOKBEHIND(m_pos,out); assert(t > 0); NEED_OP(t+3-1);
		goto copy_match;
#endif
	    }
	    else if (t >= 32)
	    {
		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
#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) && (LZO_BYTE_ORDER == LZO_LITTLE_ENDIAN)
		m_pos = op - 1;
		m_pos -= (* (const lzo_ushortp) ip) >> 2;
#else
		m_pos = op - 1;
		m_pos -= (ip[0] >> 2) + (ip[1] << 6);
#endif
#endif
		ip += 2;
	    }
	    else if (t >= 16)
	    {
#if defined(COPY_DICT)
		m_off = (t & 8) << 11;
#else
		m_pos = op;
		m_pos -= (t & 8) << 11;
#endif
		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)