mirror of
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
99 lines
1.8 KiB
Go
99 lines
1.8 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 main
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import (
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"crypto/sha256"
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"flag"
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"fmt"
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"io"
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"os"
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"time"
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_ "github.com/syncthing/syncthing/lib/automaxprocs"
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)
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func main() {
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period := flag.Duration("period", 200*time.Millisecond, "Sleep period between checks")
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flag.Parse()
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file := flag.Arg(0)
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if file == "" {
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fmt.Println("Expects a path as an argument")
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return
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}
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exists := true
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size := int64(0)
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mtime := time.Time{}
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var hash [sha256.Size]byte
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for {
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time.Sleep(*period)
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newExists := true
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fi, err := os.Stat(file)
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if err != nil && os.IsNotExist(err) {
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newExists = false
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} else if err != nil {
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fmt.Println("stat:", err)
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return
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}
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if newExists != exists {
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exists = newExists
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if !newExists {
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fmt.Println(file, "does not exist")
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} else {
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fmt.Println(file, "appeared")
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}
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}
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if !exists {
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size = 0
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mtime = time.Time{}
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hash = [sha256.Size]byte{}
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continue
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}
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if fi.IsDir() {
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fmt.Println(file, "is directory")
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return
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}
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newSize := fi.Size()
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newMtime := fi.ModTime()
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newHash, err := sha256file(file)
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if err != nil {
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fmt.Println("sha256file:", err)
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}
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if newSize != size || newMtime != mtime || newHash != hash {
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fmt.Println(file, "Size:", newSize, "Mtime:", newMtime, "Hash:", fmt.Sprintf("%x", newHash))
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hash = newHash
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size = newSize
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mtime = newMtime
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}
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}
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}
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func sha256file(fname string) (hash [sha256.Size]byte, err error) {
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f, err := os.Open(fname)
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if err != nil {
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return
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}
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defer f.Close()
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h := sha256.New()
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io.Copy(h, f)
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hb := h.Sum(nil)
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copy(hash[:], hb)
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return
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}
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