codelength.h

/* Project : miniupnp
 * Author : Thomas BERNARD
 * copyright (c) 2005-2008 Thomas Bernard
 * This software is subjet to the conditions detailed in the
 * provided LICENCE file. */
#ifndef __CODELENGTH_H__
#define __CODELENGTH_H__

/* 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);

#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