syncthing/cmd/stcrashreceiver/util.go
Gusted 356c5055ad
lib/sha256: Remove it (#9643)
### 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 since
7b8a7f8272,
`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
2024-08-10 12:58:20 +01:00

57 lines
1.4 KiB
Go

// Copyright (C) 2021 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.
package main
import (
"bytes"
"compress/gzip"
"crypto/sha256"
"fmt"
"net"
"net/http"
"os"
"path/filepath"
"time"
)
// userIDFor returns a string we can use as the user ID for the purpose of
// counting affected users. It's the truncated hash of a salt, the user
// remote IP, and the current month.
func userIDFor(req *http.Request) string {
addr := req.RemoteAddr
if fwd := req.Header.Get("x-forwarded-for"); fwd != "" {
addr = fwd
}
if host, _, err := net.SplitHostPort(addr); err == nil {
addr = host
}
now := time.Now().Format("200601")
salt := "stcrashreporter"
hash := sha256.Sum256([]byte(salt + addr + now))
return fmt.Sprintf("%x", hash[:8])
}
// 01234567890abcdef... => 01/23
func dirFor(base string) string {
return filepath.Join(base[0:2], base[2:4])
}
func fullPathCompressed(root, reportID string) string {
return filepath.Join(root, dirFor(reportID), reportID) + ".gz"
}
func compressAndWrite(bs []byte, fullPath string) error {
// Compress the report for storage
buf := new(bytes.Buffer)
gw := gzip.NewWriter(buf)
_, _ = gw.Write(bs) // can't fail
gw.Close()
// Create an output file with the compressed report
return os.WriteFile(fullPath, buf.Bytes(), 0644)
}