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