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](https://github.com/golang/go/commit/1a64574f42b95594cf9c8a12e9ca13d75585429c).
Therefore using `sha256-simd` has no benefits anymore.

ARM already has optimized sha256 assembly code since
https://github.com/golang/go/commit/7b8a7f8272fd1941a199af1adb334bd9996e8909,
`sha256-simd` published their results before that optimized assembly was
implemented,
https://github.com/minio/sha256-simd/commit/f941fedda826b68a196de2e0a9183e273ec0cb91.
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

This commit is contained in:

Gusted

2024-08-10 12:58:20 +01:00

committed by

GitHub

parent 19693734a3

commit 356c5055ad

26 changed files with 17 additions and 217 deletions

									
										man/syncthing.1
									
		-5
	
												View File
												
				@@ -555,11 +555,6 @@ passing \fI\%\-\-gui\-apikey\fP\&.

				Directory to load GUI assets from. Overrides compiled in assets. Useful for

				developing webgui, commonly use \fBSTGUIASSETS=gui bin/syncthing\fP\&.

				.TP

				.B STHASHING

				Specify which hashing package to use. Defaults to automatic based on

				performance. Specify “minio” (compatibility) or “standard” for the default

				Go implementation.

				.TP

				.B STHEAPPROFILE

				Write heap profiles to \fBheap\-$pid\-$timestamp.pprof\fP each time heap usage

				increases.