1/* $Id: codelength.h,v 1.4 2012/09/27 15:40:29 nanard Exp $ */
2/* Project : miniupnp
3 * Author : Thomas BERNARD
4 * copyright (c) 2005-2011 Thomas Bernard
5 * This software is subjet to the conditions detailed in the
6 * provided LICENCE file. */
7#ifndef CODELENGTH_H_INCLUDED
8#define CODELENGTH_H_INCLUDED
9
10/* Encode length by using 7bit per Byte :
11 * Most significant bit of each byte specifies that the
12 * following byte is part of the code */
13#define DECODELENGTH(n, p) n = 0; \
14                           do { n = (n << 7) | (*p & 0x7f); } \
15                           while((*(p++)&0x80) && (n<(1<<25)));
16
17#define DECODELENGTH_CHECKLIMIT(n, p, p_limit) \
18	n = 0; \
19	do { \
20		if((p) >= (p_limit)) break; \
21		n = (n << 7) | (*(p) & 0x7f); \
22	} while((*((p)++)&0x80) && (n<(1<<25)));
23
24#define CODELENGTH(n, p) if(n>=268435456) *(p++) = (n >> 28) | 0x80; \
25                         if(n>=2097152) *(p++) = (n >> 21) | 0x80; \
26                         if(n>=16384) *(p++) = (n >> 14) | 0x80; \
27                         if(n>=128) *(p++) = (n >> 7) | 0x80; \
28                         *(p++) = n & 0x7f;
29
30#endif
31
32