35 lines
950 B
Go
35 lines
950 B
Go
|
package cid
|
||
|
|
||
|
// Version of varint function that work with a string rather than
|
||
|
// []byte to avoid unnecessary allocation
|
||
|
|
||
|
// Copyright 2011 The Go Authors. All rights reserved.
|
||
|
// Use of this source code is governed by a BSD-style
|
||
|
// license as given at https://golang.org/LICENSE
|
||
|
|
||
|
// uvarint decodes a uint64 from buf and returns that value and the
|
||
|
// number of characters read (> 0). If an error occurred, the value is 0
|
||
|
// and the number of bytes n is <= 0 meaning:
|
||
|
//
|
||
|
// n == 0: buf too small
|
||
|
// n < 0: value larger than 64 bits (overflow)
|
||
|
// and -n is the number of bytes read
|
||
|
//
|
||
|
func uvarint(buf string) (uint64, int) {
|
||
|
var x uint64
|
||
|
var s uint
|
||
|
// we have a binary string so we can't use a range loope
|
||
|
for i := 0; i < len(buf); i++ {
|
||
|
b := buf[i]
|
||
|
if b < 0x80 {
|
||
|
if i > 9 || i == 9 && b > 1 {
|
||
|
return 0, -(i + 1) // overflow
|
||
|
}
|
||
|
return x | uint64(b)<<s, i + 1
|
||
|
}
|
||
|
x |= uint64(b&0x7f) << s
|
||
|
s += 7
|
||
|
}
|
||
|
return 0, 0
|
||
|
}
|