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GitHub Repository: godotengine/godot
 Path: blob/master/thirdparty/miniupnpc/src/codelength.h
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/* $Id: codelength.h,v 1.3 2011/07/30 13:10:05 nanard Exp $ */

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/* Project : miniupnp

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 * Author : Thomas BERNARD

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 * copyright (c) 2005-2015 Thomas Bernard

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 * This software is subjet to the conditions detailed in the

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 * provided LICENCE file. */

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#ifndef CODELENGTH_H_INCLUDED

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#define CODELENGTH_H_INCLUDED

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/* Encode length by using 7bit per Byte :

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 * Most significant bit of each byte specifies that the

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 * following byte is part of the code */

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/* n : unsigned

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 * p : unsigned char *

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 */

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

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

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

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/* n :    unsigned

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 * READ : function/macro to read one byte (unsigned char)

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 */

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#define DECODELENGTH_READ(n, READ) \

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	n = 0; \

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	do { \

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		unsigned char c; \

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		READ(c); \

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		n = (n << 7) | (c & 0x07f); \

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		if(!(c&0x80)) break; \

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	} while(n<(1<<25));

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/* n :       unsigned

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 * p :       unsigned char *

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 * p_limit : unsigned char *

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 */

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#define DECODELENGTH_CHECKLIMIT(n, p, p_limit) \

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	n = 0; \

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	do { \

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		if((p) >= (p_limit)) break; \

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

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

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/* n : unsigned

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 * p : unsigned char *

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 */

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#define CODELENGTH(n, p) if(n>=268435456) *(p++) = (n >> 28) | 0x80; \

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                         if(n>=2097152) *(p++) = (n >> 21) | 0x80; \

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                         if(n>=16384) *(p++) = (n >> 14) | 0x80; \

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                         if(n>=128) *(p++) = (n >> 7) | 0x80; \

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                         *(p++) = n & 0x7f;

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#endif /* CODELENGTH_H_INCLUDED */

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