release/src/router/miniupnpd/codelength.h

   1 /* $Id: codelength.h,v 1.1 2008/10/06 22:04:06 nanard Exp $ */
   2 /* Project : miniupnp
   3  * Author : Thomas BERNARD
   4  * copyright (c) 2005-2008 Thomas Bernard
   5  * This software is subjet to the conditions detailed in the
   6  * provided LICENCE file. */
   7 #ifndef __CODELENGTH_H__
   8 #define __CODELENGTH_H__
   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);
  16
  17 #define CODELENGTH(n, p) if(n>=268435456) *(p++) = (n >> 28) | 0x80; \
  18                          if(n>=2097152) *(p++) = (n >> 21) | 0x80; \
  19                          if(n>=16384) *(p++) = (n >> 14) | 0x80; \
  20                          if(n>=128) *(p++) = (n >> 7) | 0x80; \
  21                          *(p++) = n & 0x7f;
  22
  23 #endif
  24