Refactor avatar package, support default avatar fallback (#36788)

* Fix #34715

modules/avatar/avatar.go

@@ -28,21 +28,18 @@ import (
 // than the size after resizing.
 const DefaultAvatarSize = 256
 
-// RandomImageSize generates and returns a random avatar image unique to input data
+// RandomImageWithSize generates and returns a random avatar image unique to input data
 // in custom size (height and width).
-func RandomImageSize(size int, data []byte) (image.Image, error) {
+func RandomImageWithSize(size int, data []byte) image.Image {
 	// we use white as background, and use dark colors to draw blocks
-	imgMaker, err := identicon.New(size, color.White, identicon.DarkColors...)
-	if err != nil {
-		return nil, fmt.Errorf("identicon.New: %w", err)
-	}
-	return imgMaker.Make(data), nil
+	imgMaker := identicon.New(size, color.White, identicon.DarkColors)
+	return imgMaker.Make(data)
 }
 
-// RandomImage generates and returns a random avatar image unique to input data
+// RandomImageDefaultSize generates and returns a random avatar image unique to input data
 // in default size (height and width).
-func RandomImage(data []byte) (image.Image, error) {
-	return RandomImageSize(DefaultAvatarSize*setting.Avatar.RenderedSizeFactor, data)
+func RandomImageDefaultSize(data []byte) image.Image {
+	return RandomImageWithSize(DefaultAvatarSize*setting.Avatar.RenderedSizeFactor, data)
 }
 
 // processAvatarImage process the avatar image data, crop and resize it if necessary.

modules/avatar/avatar_test.go

@@ -15,19 +15,6 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func Test_RandomImageSize(t *testing.T) {
-	_, err := RandomImageSize(0, []byte("gitea@local"))
-	assert.Error(t, err)
-
-	_, err = RandomImageSize(64, []byte("gitea@local"))
-	assert.NoError(t, err)
-}
-
-func Test_RandomImage(t *testing.T) {
-	_, err := RandomImage([]byte("gitea@local"))
-	assert.NoError(t, err)
-}
-
 func Test_ProcessAvatarPNG(t *testing.T) {
 	setting.Avatar.MaxWidth = 4096
 	setting.Avatar.MaxHeight = 4096
@@ -134,3 +121,18 @@ func Test_ProcessAvatarImage(t *testing.T) {
 	_, err = processAvatarImage(origin, 262144)
 	assert.ErrorContains(t, err, "image width is too large: 10 > 5")
 }
+
+func BenchmarkRandomImage(b *testing.B) {
+	b.Run("size-48", func(b *testing.B) {
+		for b.Loop() {
+			// BenchmarkRandomImage/size-48-12         	   49549	     22899 ns/op
+			RandomImageWithSize(48, []byte("test-content"))
+		}
+	})
+	b.Run("size-96", func(b *testing.B) {
+		for b.Loop() {
+			// BenchmarkRandomImage/size-96-12         	   13816	     88187 ns/op
+			RandomImageWithSize(96, []byte("test-content"))
+		}
+	})
+}

modules/avatar/identicon/identicon.go

@@ -8,13 +8,14 @@ package identicon
 
 import (
 	"crypto/sha256"
-	"errors"
-	"fmt"
 	"image"
 	"image/color"
 )
 
-const minImageSize = 16
+const (
+	minImageSize = 16
+	maxImageSize = 2048
+)
 
 // Identicon is used to generate pseudo-random avatars
 type Identicon struct {
@@ -24,25 +25,17 @@ type Identicon struct {
 	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, errors.New("foreground is not set")
-	}
-
-	if size < minImageSize {
-		return nil, fmt.Errorf("size %d is smaller than min size %d", size, minImageSize)
-	}
-
+// New returns an Identicon struct.
+// Only one foreground color will be picked randomly for one image.
+func New(size int, backColor color.Color, foreColors []color.Color) *Identicon {
+	size = max(size, minImageSize)
+	size = min(size, maxImageSize)
 	return &Identicon{
-		foreColors: fore,
-		backColor:  back,
+		foreColors: foreColors,
+		backColor:  backColor,
 		size:       size,
 		rect:       image.Rect(0, 0, size, size),
-	}, nil
+	}
 }
 
 // Make generates an avatar by data

modules/avatar/identicon/identicon_test.go

@@ -23,7 +23,7 @@ func TestGenerate(t *testing.T) {
 	}
 
 	backColor := color.White
-	imgMaker, err := New(64, backColor, DarkColors...)
+	imgMaker, err := New(64, backColor, DarkColors)
 	assert.NoError(t, err)
 	for i := 0; i < 100; i++ {
 		s := strconv.Itoa(i)