iu
04617d1cdb
- backend: user_avatar_objects binding (PG+SQLite), GC preserves avatar blobs, avatar service (EXIF-stripping WebP 128/512), public avatar read route - web: avatar upload/crop on profile, round avatar in header/members/comments/author - android: avatar upload/crop, round avatar on profile and albums header - openspec: add-user-avatar proposal/design/specs/tasks
57 lines
1.7 KiB
Go
57 lines
1.7 KiB
Go
// Package avatar manages a user's profile photo: it normalises an uploaded
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// image into square WebP variants and keeps them as journaled objects bound to
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// the user, so the object ledger's garbage collection preserves them.
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package avatar
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import (
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"bytes"
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"errors"
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"image"
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"github.com/disintegration/imaging"
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"github.com/gen2brain/webp"
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)
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// Canonical avatar sizes. The small variant serves lists and headers; the large
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// one serves the profile page.
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const (
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SizeLarge = 512
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SizeSmall = 128
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)
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// maxUploadBytes caps an avatar upload. Avatars are small, so a generous
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// general image limit would let a client stream needlessly.
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const maxUploadBytes = 10 << 20
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var errInvalidImage = errors.New("invalid image")
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// normalize decodes an uploaded image and produces two square WebP variants.
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// Decoding honours the EXIF orientation; re-encoding discards all metadata
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// (including GPS), so the stored avatar carries none of the original's.
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func normalize(data []byte) (large, small []byte, err error) {
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img, err := imaging.Decode(bytes.NewReader(data), imaging.AutoOrientation(true))
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if err != nil {
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return nil, nil, errInvalidImage
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}
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large, err = fillWebP(img, SizeLarge)
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if err != nil {
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return nil, nil, err
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}
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small, err = fillWebP(img, SizeSmall)
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if err != nil {
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return nil, nil, err
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}
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return large, small, nil
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}
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// fillWebP centre-crops the image to a square of the given size and encodes it
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// as WebP.
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func fillWebP(img image.Image, size int) ([]byte, error) {
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square := imaging.Fill(img, size, size, imaging.Center, imaging.Lanczos)
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var buf bytes.Buffer
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if err := webp.Encode(&buf, square, webp.Options{Quality: 82}); err != nil {
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return nil, err
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}
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return buf.Bytes(), nil
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}
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