forgejo/modules/avatar/identicon/identicon.go
Gusted fa37a211fb
[GITEA] Drop sha256-simd in favor of stdlib
- 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%
```

(cherry picked from commit abd94ff5b59c86e793fd9bf12187ea6cfd1f3fa1)
(cherry picked from commit 15e81637abf70576a564cf9eecaa9640228afb5b)

Conflicts:
	go.mod
	https://codeberg.org/forgejo/forgejo/pulls/1581
(cherry picked from commit 325d92917f655c999b81b08832ee623d6b669f0f)

Conflicts:
	modules/context/context_cookie.go
	https://codeberg.org/forgejo/forgejo/pulls/1617
(cherry picked from commit 358819e8959886faa171ac16541097500d0a703e)
(cherry picked from commit 362fd7aae17832fa922fa017794bc564ca43060d)
(cherry picked from commit 4f64ee294ee05c93042b6ec68f0a179ec249dab9)
(cherry picked from commit 4bde77f7b13c5f961c141c01b6da1f9eda5ec387)
(cherry picked from commit 1311e30a811675eb623692349e4e808a85aabef6)
(cherry picked from commit 57b69e334c2973118488b9b5dbdc8a2c88135756)
(cherry picked from commit 52dc892fadecf39e89c3c351edc9efb42522257b)
(cherry picked from commit 77f54f4187869c6eabcc837742fd3f908093a76c)
(cherry picked from commit 0d0392f3a510ce3683bb649dee1e65b45dd91354)

Conflicts:
	go.mod
	https://codeberg.org/forgejo/forgejo/pulls/2034
(cherry picked from commit 92798364e8fe3188a2100b54f3adea943f8309e9)
(cherry picked from commit 43d218127752aa9251c4c3ef71b9c060f109dffc)
(cherry picked from commit 45c88b86a35729fc0b2dc6b72bc33caf9f69265f)
(cherry picked from commit a1cd6f4e3a7956773cbc0aef8abb80d17b62eb49)
(cherry picked from commit 01191dc2adf8c57ae448be37e73158005a8ff74d)
(cherry picked from commit 151e07f37e2854ad633f1352fb0ce3cd06f4b2ae)
2024-02-05 16:09:40 +01:00

141 lines
3.8 KiB
Go

// Copyright 2021 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
// Copied and modified from https://github.com/issue9/identicon/ (MIT License)
// Generate pseudo-random avatars by IP, E-mail, etc.
package identicon
import (
"crypto/sha256"
"fmt"
"image"
"image/color"
)
const minImageSize = 16
// Identicon is used to generate pseudo-random avatars
type Identicon struct {
foreColors []color.Color
backColor color.Color
size int
rect image.Rectangle
}
// New returns an Identicon struct with the correct settings
// size image size
// back background color
// fore all possible foreground colors. only one foreground color will be picked randomly for one image
func New(size int, back color.Color, fore ...color.Color) (*Identicon, error) {
if len(fore) == 0 {
return nil, fmt.Errorf("foreground is not set")
}
if size < minImageSize {
return nil, fmt.Errorf("size %d is smaller than min size %d", size, minImageSize)
}
return &Identicon{
foreColors: fore,
backColor: back,
size: size,
rect: image.Rect(0, 0, size, size),
}, nil
}
// Make generates an avatar by data
func (i *Identicon) Make(data []byte) image.Image {
h := sha256.New()
h.Write(data)
sum := h.Sum(nil)
b1 := int(sum[0]+sum[1]+sum[2]) % len(blocks)
b2 := int(sum[3]+sum[4]+sum[5]) % len(blocks)
c := int(sum[6]+sum[7]+sum[8]) % len(centerBlocks)
b1Angle := int(sum[9]+sum[10]) % 4
b2Angle := int(sum[11]+sum[12]) % 4
foreColor := int(sum[11]+sum[12]+sum[15]) % len(i.foreColors)
return i.render(c, b1, b2, b1Angle, b2Angle, foreColor)
}
func (i *Identicon) render(c, b1, b2, b1Angle, b2Angle, foreColor int) image.Image {
p := image.NewPaletted(i.rect, []color.Color{i.backColor, i.foreColors[foreColor]})
drawBlocks(p, i.size, centerBlocks[c], blocks[b1], blocks[b2], b1Angle, b2Angle)
return p
}
/*
# Algorithm
Origin: An image is splitted into 9 areas
```
-------------
| 1 | 2 | 3 |
-------------
| 4 | 5 | 6 |
-------------
| 7 | 8 | 9 |
-------------
```
Area 1/3/9/7 use a 90-degree rotating pattern.
Area 1/3/9/7 use another 90-degree rotating pattern.
Area 5 uses a random pattern.
The Patched Fix: make the image left-right mirrored to get rid of something like "swastika"
*/
// draw blocks to the paletted
// c: the block drawer for the center block
// b1,b2: the block drawers for other blocks (around the center block)
// b1Angle,b2Angle: the angle for the rotation of b1/b2
func drawBlocks(p *image.Paletted, size int, c, b1, b2 blockFunc, b1Angle, b2Angle int) {
nextAngle := func(a int) int {
return (a + 1) % 4
}
padding := (size % 3) / 2 // in cased the size can not be aligned by 3 blocks.
blockSize := size / 3
twoBlockSize := 2 * blockSize
// center
c(p, blockSize+padding, blockSize+padding, blockSize, 0)
// left top (1)
b1(p, 0+padding, 0+padding, blockSize, b1Angle)
// center top (2)
b2(p, blockSize+padding, 0+padding, blockSize, b2Angle)
b1Angle = nextAngle(b1Angle)
b2Angle = nextAngle(b2Angle)
// right top (3)
// b1(p, twoBlockSize+padding, 0+padding, blockSize, b1Angle)
// right middle (6)
// b2(p, twoBlockSize+padding, blockSize+padding, blockSize, b2Angle)
b1Angle = nextAngle(b1Angle)
b2Angle = nextAngle(b2Angle)
// right bottom (9)
// b1(p, twoBlockSize+padding, twoBlockSize+padding, blockSize, b1Angle)
// center bottom (8)
b2(p, blockSize+padding, twoBlockSize+padding, blockSize, b2Angle)
b1Angle = nextAngle(b1Angle)
b2Angle = nextAngle(b2Angle)
// lef bottom (7)
b1(p, 0+padding, twoBlockSize+padding, blockSize, b1Angle)
// left middle (4)
b2(p, 0+padding, blockSize+padding, blockSize, b2Angle)
// then we make it left-right mirror, so we didn't draw 3/6/9 before
for x := 0; x < size/2; x++ {
for y := 0; y < size; y++ {
p.SetColorIndex(size-x, y, p.ColorIndexAt(x, y))
}
}
}