miniupnp/miniupnpd/codelength.h at master · symform/miniupnp

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/* $Id: codelength.h,v 1.3 2011/07/30 13:10:05 nanard Exp $ */

/* Project : miniupnp

* Author : 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 */

#define DECODELENGTH(n, p) n = 0; \

do { n = (n << 7) | (*p & 0x7f); } \

while((*(p++)&0x80) && (n<(1<<25)));

#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)));

#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