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https://github.com/octoleo/syncthing.git
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356c5055ad
### Purpose Remove the `lib/sha256` package, because it's no longer necessary. Go's standard library now has the same performance and is on par with `sha256-simd` since [Since Go 1.21](1a64574f42). Therefore using `sha256-simd` has no benefits anymore. ARM already has optimized sha256 assembly code since7b8a7f8272, `sha256-simd` published their results before that optimized assembly was implemented,f941fedda8. The assembly looks very similar and the benchmarks in the Go commit match that of `sha256-simd`. This patch removes all of the related code of `lib/sha256` and makes `crypto/sha256` the 'default'. Benchmark of `sha256-simd` and `crypto/sha256`: <details> ``` 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% ``` </details> ### Testing Compiled and tested on Linux. ### Documentation https://github.com/syncthing/docs/pull/874
60 lines
1.5 KiB
Go
60 lines
1.5 KiB
Go
// Copyright (C) 2015 The Syncthing Authors.
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//
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// This Source Code Form is subject to the terms of the Mozilla Public
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// License, v. 2.0. If a copy of the MPL was not distributed with this file,
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// You can obtain one at https://mozilla.org/MPL/2.0/.
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package fs
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import (
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"crypto/sha256"
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"fmt"
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"path/filepath"
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"strings"
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"github.com/syncthing/syncthing/lib/build"
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)
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const (
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WindowsTempPrefix = "~syncthing~"
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UnixTempPrefix = ".syncthing."
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)
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func tempPrefix() string {
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if build.IsWindows {
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return WindowsTempPrefix
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} else {
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return UnixTempPrefix
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}
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}
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// Real filesystems usually handle 255 bytes. encfs has varying and
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// confusing file name limits. We take a safe way out and switch to hashing
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// quite early.
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const maxFilenameLength = 160 - len(UnixTempPrefix) - len(".tmp")
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// IsTemporary is true if the file name has the temporary prefix. Regardless
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// of the normally used prefix, the standard Windows and Unix temp prefixes
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// are always recognized as temp files.
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func IsTemporary(name string) bool {
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name = filepath.Base(name)
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return strings.HasPrefix(name, WindowsTempPrefix) ||
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strings.HasPrefix(name, UnixTempPrefix)
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}
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func TempNameWithPrefix(name, prefix string) string {
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tdir := filepath.Dir(name)
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tbase := filepath.Base(name)
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var tname string
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if len(tbase) > maxFilenameLength {
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tname = fmt.Sprintf("%s%x.tmp", prefix, sha256.Sum256([]byte(tbase)))
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} else {
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tname = prefix + tbase + ".tmp"
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}
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return filepath.Join(tdir, tname)
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}
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func TempName(name string) string {
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return TempNameWithPrefix(name, tempPrefix())
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}
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