thodg/libgit2/src/varint.c

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• Hash : 0c7f49dd
  Author :
  Date : 2017-06-30T13:39:01
  

  Make sure to always include "common.h" first Next to including several files, our "common.h" header also declares various macros which are then used throughout the project. As such, we have to make sure to always include this file first in all implementation files. Otherwise, we might encounter problems or even silent behavioural differences due to macros or defines not being defined as they should be. So in fact, our header and implementation files should make sure to always include "common.h" first. This commit does so by establishing a common include pattern. Header files inside of "src" will now always include "common.h" as its first other file, separated by a newline from all the other includes to make it stand out as special. There are two cases for the implementation files. If they do have a matching header file, they will always include this one first, leading to "common.h" being transitively included as first file. If they do not have a matching header file, they instead include "common.h" as first file themselves. This fixes the outlined problems and will become our standard practice for header and source files inside of the "src/" from now on.

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• src/varint.c

• /*
   * Copyright (C) the libgit2 contributors. All rights reserved.
   *
   * This file is part of libgit2, distributed under the GNU GPL v2 with
   * a Linking Exception. For full terms see the included COPYING file.
   */
  
  #include "varint.h"
  
  uintmax_t git_decode_varint(const unsigned char *bufp, size_t *varint_len)
  {
  	const unsigned char *buf = bufp;
  	unsigned char c = *buf++;
  	uintmax_t val = c & 127;
  	while (c & 128) {
  		val += 1;
  		if (!val || MSB(val, 7)) {
  			/* This is not a valid varint_len, so it signals
  			   the error */
  			*varint_len = 0;
  			return 0; /* overflow */
  		}
  		c = *buf++;
  		val = (val << 7) + (c & 127);
  	}
  	*varint_len = buf - bufp;
  	return val;
  }
  
  int git_encode_varint(unsigned char *buf, size_t bufsize, uintmax_t value)
  {
  	unsigned char varint[16];
  	unsigned pos = sizeof(varint) - 1;
  	varint[pos] = value & 127;
  	while (value >>= 7)
  		varint[--pos] = 128 | (--value & 127);
  	if (buf) {
  		if (bufsize < (sizeof(varint) - pos))
  			return -1;
  		memcpy(buf, varint + pos, sizeof(varint) - pos);
  	}
  	return sizeof(varint) - pos;
  }
  

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