HoneyandClaude Opus 5
31a027c93a
Go-Backend (chi, pgx, golang-migrate) + React/TS-Frontend als PWA. Enthalten: Auth inkl. OIDC, Dateien mit Versionen und Papierkorb, Freigaben (Links + intern), WebDAV, Gruppenordner, Admin/Theming, Volltextsuche mit OCR, eigener PDF-Betrachter und WOPI-Office (Collabora/OnlyOffice). Nicht im Repo: deploy/.env (Sitzungsschlüssel, DB- und Admin-Passwort) sowie alle Daten- und Build-Verzeichnisse – siehe .gitignore. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
96 lines
2.1 KiB
Go
96 lines
2.1 KiB
Go
package thumbnails
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import (
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"bytes"
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"context"
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"fmt"
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"image"
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_ "image/gif"
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"image/jpeg"
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_ "image/png"
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_ "golang.org/x/image/webp" // SupportedMIME nennt WebP – ohne den Dekodierer entstand dafür nie ein Vorschaubild
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"io"
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"strings"
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"golang.org/x/image/draw"
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"aether/internal/storage"
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)
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const (
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maxWidth = 256
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maxHeight = 256
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)
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// SupportedMIME returns true if we can generate a thumbnail for this MIME type.
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func SupportedMIME(mime string) bool {
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m := strings.ToLower(mime)
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return strings.HasPrefix(m, "image/jpeg") ||
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strings.HasPrefix(m, "image/png") ||
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strings.HasPrefix(m, "image/gif") ||
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strings.HasPrefix(m, "image/webp")
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}
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// ThumbnailKey returns the storage key for a file's thumbnail.
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func ThumbnailKey(fileID string) string {
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return "thumbs/" + fileID + ".jpg"
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}
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// Generate reads an image from src, creates a thumbnail, and stores it.
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// Returns nil if generation succeeds, error otherwise.
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func Generate(ctx context.Context, st storage.Storage, fileID, mimeType string, src io.Reader) error {
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if !SupportedMIME(mimeType) {
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return fmt.Errorf("unsupported MIME type: %s", mimeType)
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}
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img, _, err := image.Decode(src)
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if err != nil {
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return fmt.Errorf("decode image: %w", err)
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}
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thumb := resize(img, maxWidth, maxHeight)
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var buf bytes.Buffer
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if err := jpeg.Encode(&buf, thumb, &jpeg.Options{Quality: 80}); err != nil {
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return fmt.Errorf("encode thumbnail: %w", err)
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}
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key := ThumbnailKey(fileID)
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if _, _, err := st.Put(ctx, key, &buf); err != nil {
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return fmt.Errorf("store thumbnail: %w", err)
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}
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return nil
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}
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func resize(src image.Image, maxW, maxH int) image.Image {
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bounds := src.Bounds()
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w, h := bounds.Dx(), bounds.Dy()
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if w == 0 || h == 0 {
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return src
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}
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scaleW := float64(maxW) / float64(w)
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scaleH := float64(maxH) / float64(h)
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scale := scaleW
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if scaleH < scale {
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scale = scaleH
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}
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if scale >= 1 {
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return src // already smaller than max
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}
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newW := int(float64(w) * scale)
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newH := int(float64(h) * scale)
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if newW < 1 {
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newW = 1
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}
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if newH < 1 {
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newH = 1
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}
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dst := image.NewRGBA(image.Rect(0, 0, newW, newH))
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draw.BiLinear.Scale(dst, dst.Bounds(), src, src.Bounds(), draw.Over, nil)
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return dst
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}
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