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/*
* 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 "common.h"
#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 < pos)
return -1;
memcpy(buf, varint + pos, sizeof(varint) - pos);
}
return sizeof(varint) - pos;
}
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