abd94ff5b5
- In Go 1.21 the crypto/sha256 [got a massive improvement](https://go.dev/doc/go1.21#crypto/sha256) by utilizing the SHA instructions for AMD64 CPUs, which sha256-simd already was doing. The performance is now on par and I think it's preferable to use the standard library rather than a package when possible. ``` cpu: AMD Ryzen 5 3600X 6-Core Processor │ simd.txt │ go.txt │ │ sec/op │ sec/op vs base │ Hash/8Bytes-12 63.25n ± 1% 73.38n ± 1% +16.02% (p=0.002 n=6) Hash/64Bytes-12 98.73n ± 1% 105.30n ± 1% +6.65% (p=0.002 n=6) Hash/1K-12 567.2n ± 1% 572.8n ± 1% +0.99% (p=0.002 n=6) Hash/8K-12 4.062µ ± 1% 4.062µ ± 1% ~ (p=0.396 n=6) Hash/1M-12 512.1µ ± 0% 510.6µ ± 1% ~ (p=0.485 n=6) Hash/5M-12 2.556m ± 1% 2.564m ± 0% ~ (p=0.093 n=6) Hash/10M-12 5.112m ± 0% 5.127m ± 0% ~ (p=0.093 n=6) geomean 13.82µ 14.27µ +3.28% │ simd.txt │ go.txt │ │ B/s │ B/s vs base │ Hash/8Bytes-12 120.6Mi ± 1% 104.0Mi ± 1% -13.81% (p=0.002 n=6) Hash/64Bytes-12 618.2Mi ± 1% 579.8Mi ± 1% -6.22% (p=0.002 n=6) Hash/1K-12 1.682Gi ± 1% 1.665Gi ± 1% -0.98% (p=0.002 n=6) Hash/8K-12 1.878Gi ± 1% 1.878Gi ± 1% ~ (p=0.310 n=6) Hash/1M-12 1.907Gi ± 0% 1.913Gi ± 1% ~ (p=0.485 n=6) Hash/5M-12 1.911Gi ± 1% 1.904Gi ± 0% ~ (p=0.093 n=6) Hash/10M-12 1.910Gi ± 0% 1.905Gi ± 0% ~ (p=0.093 n=6) geomean 1.066Gi 1.032Gi -3.18% ```
28 lines
978 B
Go
28 lines
978 B
Go
// Copyright 2023 The Gitea Authors. All rights reserved.
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// SPDX-License-Identifier: MIT
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package avatar
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import (
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"crypto/sha256"
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"encoding/hex"
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"strconv"
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)
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// HashAvatar will generate a unique string, which ensures that when there's a
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// different unique ID while the data is the same, it will generate a different
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// output. It will generate the output according to:
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// HEX(HASH(uniqueID || - || data))
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// The hash being used is SHA256.
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// The sole purpose of the unique ID is to generate a distinct hash Such that
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// two unique IDs with the same data will have a different hash output.
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// The "-" byte is important to ensure that data cannot be modified such that
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// the first byte is a number, which could lead to a "collision" with the hash
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// of another unique ID.
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func HashAvatar(uniqueID int64, data []byte) string {
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h := sha256.New()
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h.Write([]byte(strconv.FormatInt(uniqueID, 10)))
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h.Write([]byte{'-'})
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h.Write(data)
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return hex.EncodeToString(h.Sum(nil))
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}
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