54 lines
1.5 KiB
C++
54 lines
1.5 KiB
C++
/* $Id: codelength.h,v 1.3 2011/07/30 13:10:05 nanard Exp $ */
|
|
/* Project : miniupnp
|
|
* Author : Thomas BERNARD
|
|
* copyright (c) 2005-2015 Thomas Bernard
|
|
* This software is subjet to the conditions detailed in the
|
|
* provided LICENCE file. */
|
|
#ifndef CODELENGTH_H_INCLUDED
|
|
#define CODELENGTH_H_INCLUDED
|
|
|
|
/* Encode length by using 7bit per Byte :
|
|
* Most significant bit of each byte specifies that the
|
|
* following byte is part of the code */
|
|
|
|
/* n : unsigned
|
|
* p : unsigned char *
|
|
*/
|
|
#define DECODELENGTH(n, p) n = 0; \
|
|
do { n = (n << 7) | (*p & 0x7f); } \
|
|
while((*(p++)&0x80) && (n<(1<<25)));
|
|
|
|
/* n : unsigned
|
|
* READ : function/macro to read one byte (unsigned char)
|
|
*/
|
|
#define DECODELENGTH_READ(n, READ) \
|
|
n = 0; \
|
|
do { \
|
|
unsigned char c; \
|
|
READ(c); \
|
|
n = (n << 7) | (c & 0x07f); \
|
|
if(!(c&0x80)) break; \
|
|
} while(n<(1<<25));
|
|
|
|
/* n : unsigned
|
|
* p : unsigned char *
|
|
* p_limit : unsigned char *
|
|
*/
|
|
#define DECODELENGTH_CHECKLIMIT(n, p, p_limit) \
|
|
n = 0; \
|
|
do { \
|
|
if((p) >= (p_limit)) break; \
|
|
n = (n << 7) | (*(p) & 0x7f); \
|
|
} while((*((p)++)&0x80) && (n<(1<<25)));
|
|
|
|
|
|
/* n : unsigned
|
|
* p : unsigned char *
|
|
*/
|
|
#define CODELENGTH(n, p) if(n>=268435456) *(p++) = (n >> 28) | 0x80; \
|
|
if(n>=2097152) *(p++) = (n >> 21) | 0x80; \
|
|
if(n>=16384) *(p++) = (n >> 14) | 0x80; \
|
|
if(n>=128) *(p++) = (n >> 7) | 0x80; \
|
|
*(p++) = n & 0x7f;
|
|
|
|
#endif /* CODELENGTH_H_INCLUDED */
|