gitforge/models/user/avatar.go
Antonin Delpeuch 0a57672544 feat: serve downsized versions of avatars (#11242)
Fixes #2325.

This introduces a way to download downsized versions of the user and repository avatars:
* `/avatars/123abcd` still serves the full-size avatar
* `/avatars/123abcd?size=64` serves it at size 64x64 px

Those downsized versions are computed on demand when requested for the first time and cached. The caching is done in a storage location configurable in the instance settings, just like the storage locations for the full-sized avatars are. The sizes of the downsized images are restricted to a fixed set of sizes, so that the cache doesn't grow too big. The caching and resizing logic is exposed in a way that could potentially be reused for other types of images (such as user uploads in issue discussions).

Luckily, the Go templates already specify in many places which size those avatars should be rendered, even if this information was only used for external avatar providers (such as Gravatar) until now.

The range of sizes requested by the HTML templates is rather wide: the table below lists all the sizes I could find, and the corresponding size served by the backend with the logic I implemented. The scaling factor of 2 was already used for requesting resized external avatars, and likely exists to make sure that users with display scaling enabled get a sharper picture.

| Size requested in the template | After scaling (x2)  | Size of the image served |
|---------|---------|---------|
| 256 px |  512 px | original (512 px) |
| 140 px | 280 px | original (512 px) |
| 48 px | 96 px | 128 px |
| 40 px | 80 px | 128 px |
| 32 px | 64 px | 64 px |
| 28 px | 56 px | 64 px |
| 24 px | 48 px | 64 px |
| 20 px | 40 px | 64 px |

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/11242
Reviewed-by: Gusted <gusted@noreply.codeberg.org>
2026-05-16 12:04:05 +02:00

120 lines
3.4 KiB
Go

// Copyright 2020 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package user
import (
"context"
"crypto/md5"
"fmt"
"image/png"
"io"
"strings"
"forgejo.org/models/avatars"
"forgejo.org/models/db"
"forgejo.org/modules/avatar"
"forgejo.org/modules/log"
"forgejo.org/modules/setting"
"forgejo.org/modules/storage"
)
// CustomAvatarRelativePath returns user custom avatar relative path.
func (u *User) CustomAvatarRelativePath() string {
return u.Avatar
}
// GenerateRandomAvatar generates a random avatar for user.
func GenerateRandomAvatar(ctx context.Context, u *User) error {
seed := u.Email
if len(seed) == 0 {
seed = u.Name
}
img, err := avatar.RandomImage([]byte(seed))
if err != nil {
return fmt.Errorf("RandomImage: %w", err)
}
u.Avatar = avatars.HashEmail(seed)
_, err = storage.Avatars.Stat(u.CustomAvatarRelativePath())
if err != nil {
// If unable to Stat the avatar file (usually it means non-existing), then try to save a new one
// Don't share the images so that we can delete them easily
if err := storage.SaveFrom(storage.Avatars, u.CustomAvatarRelativePath(), func(w io.Writer) error {
if err := png.Encode(w, img); err != nil {
log.Error("Encode: %v", err)
}
return nil
}); err != nil {
return fmt.Errorf("failed to save avatar %s: %w", u.CustomAvatarRelativePath(), err)
}
}
if _, err := db.GetEngine(ctx).ID(u.ID).Cols("avatar").Update(u); err != nil {
return err
}
log.Info("New random avatar created: %d", u.ID)
return nil
}
// AvatarLinkWithSize returns a link to the user's avatar. It may be a relative
// or absolute URL.
func (u *User) AvatarLinkWithSize(ctx context.Context, size int) string {
if u.IsGhost() || u.ID <= 0 {
return avatars.DefaultAvatarLink()
}
useLocalAvatar := false
autoGenerateAvatar := false
disableGravatar := setting.Config().Picture.DisableGravatar.Value(ctx)
switch {
case u.UseCustomAvatar:
useLocalAvatar = true
case disableGravatar, setting.OfflineMode:
useLocalAvatar = true
autoGenerateAvatar = true
}
if useLocalAvatar {
if u.Avatar == "" && autoGenerateAvatar {
if err := GenerateRandomAvatar(ctx, u); err != nil {
log.Error("GenerateRandomAvatar: %v", err)
}
}
if u.Avatar == "" {
return avatars.DefaultAvatarLink()
}
return avatars.GenerateUserResizedAvatarLink(u.Avatar, size)
}
return avatars.GenerateEmailAvatarFastLink(ctx, u.AvatarEmail, size)
}
// AvatarLink returns the full avatar link with http host
func (u *User) AvatarLink(ctx context.Context) string {
link := u.AvatarLinkWithSize(ctx, 0)
if !strings.HasPrefix(link, "//") && !strings.Contains(link, "://") {
return setting.AppURL + strings.TrimPrefix(link, setting.AppSubURL+"/")
}
return link
}
// IsUploadAvatarChanged returns true if the current user's avatar would be changed with the provided data
func (u *User) IsUploadAvatarChanged(data []byte) bool {
if !u.UseCustomAvatar || len(u.Avatar) == 0 {
return true
}
avatarID := fmt.Sprintf("%x", md5.Sum(fmt.Appendf(nil, "%d-%x", u.ID, md5.Sum(data))))
return u.Avatar != avatarID
}
// ExistsWithAvatarAtStoragePath returns true if there is a user with this Avatar
func ExistsWithAvatarAtStoragePath(ctx context.Context, storagePath string) (bool, error) {
// See func (u *User) CustomAvatarRelativePath()
// u.Avatar is used directly as the storage path - therefore we can check for existence directly using the path
return db.GetEngine(ctx).Where("`avatar`=?", storagePath).Exist(new(User))
}