sandrodachandClaude Opus 5.5
4c26eb2960
MindSift CI & Docker Release / Build, Test in Container & Push (push) Successful in 1m52s
- GET /link-preview?url= fetches the page on the server (https only, SSRF-guarded like webhooks), reads Open Graph/Twitter tags, title, description and icon from the head, loads picture and icon (no SVG) and keeps them in link_previews (migration 6) for 7 days; readers' browsers never contact the page. Off in the demo; 300 fetches per address in 15 minutes. - Compact card above the bullet (icon, site, title, one line, small picture); the duplicate link badge is left out. - ✕ turns the address into [title](url), so hiding syncs with the note; "Link-Vorschauen anzeigen" under appearance switches all off per device. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
88 lines
3.2 KiB
Go
88 lines
3.2 KiB
Go
package storage
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import (
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"crypto/sha256"
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"database/sql"
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"encoding/hex"
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"errors"
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"time"
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)
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// Link previews: title, description, a small picture and the site icon of a web page, fetched once by
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// the server and kept for a while, so readers' browsers never contact the page themselves.
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type LinkPreview struct {
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Key string `json:"key"`
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URL string `json:"url"`
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Title string `json:"title"`
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Description string `json:"description"`
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SiteName string `json:"siteName"`
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HasImage bool `json:"hasImage"`
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HasIcon bool `json:"hasIcon"`
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OK bool `json:"ok"` // false: the page gave nothing usable (kept shorter, then tried again)
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FetchedAt string `json:"fetchedAt"`
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Image, Icon []byte `json:"-"`
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ImageMime, IconMime string `json:"-"`
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}
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// LinkPreviewKey identifies the preview of a URL (also used in the picture URLs).
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func LinkPreviewKey(url string) string {
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sum := sha256.Sum256([]byte(url))
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return hex.EncodeToString(sum[:12])
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}
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func (s *Store) migrateLinkPreviews() error {
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return s.execInTx(stmt(`CREATE TABLE IF NOT EXISTS link_previews (
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key TEXT PRIMARY KEY,
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url TEXT NOT NULL,
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title TEXT NOT NULL DEFAULT '',
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description TEXT NOT NULL DEFAULT '',
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site_name TEXT NOT NULL DEFAULT '',
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image BLOB,
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image_mime TEXT NOT NULL DEFAULT '',
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icon BLOB,
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icon_mime TEXT NOT NULL DEFAULT '',
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ok INTEGER NOT NULL DEFAULT 0,
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fetched_at TEXT NOT NULL
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)`))
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}
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var ErrLinkPreviewNotFound = errors.New("Keine Vorschau vorhanden")
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func (s *Store) GetLinkPreview(key string) (*LinkPreview, error) {
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var p LinkPreview
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var ok int
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err := s.db.QueryRow(`SELECT key, url, title, description, site_name, image, image_mime, icon, icon_mime, ok, fetched_at
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FROM link_previews WHERE key = ?`, key).
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Scan(&p.Key, &p.URL, &p.Title, &p.Description, &p.SiteName, &p.Image, &p.ImageMime, &p.Icon, &p.IconMime, &ok, &p.FetchedAt)
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if errors.Is(err, sql.ErrNoRows) {
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return nil, ErrLinkPreviewNotFound
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}
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if err != nil {
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return nil, err
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}
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p.OK = ok == 1
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p.HasImage, p.HasIcon = len(p.Image) > 0, len(p.Icon) > 0
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return &p, nil
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}
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func (s *Store) SaveLinkPreview(p *LinkPreview) error {
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p.Key = LinkPreviewKey(p.URL)
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p.FetchedAt = time.Now().UTC().Format(time.RFC3339)
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_, err := s.db.Exec(`INSERT INTO link_previews (key, url, title, description, site_name, image, image_mime, icon, icon_mime, ok, fetched_at)
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VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
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ON CONFLICT(key) DO UPDATE SET url = excluded.url, title = excluded.title, description = excluded.description,
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site_name = excluded.site_name, image = excluded.image, image_mime = excluded.image_mime, icon = excluded.icon,
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icon_mime = excluded.icon_mime, ok = excluded.ok, fetched_at = excluded.fetched_at`,
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p.Key, p.URL, p.Title, p.Description, p.SiteName, p.Image, p.ImageMime, p.Icon, p.IconMime, boolInt(p.OK), p.FetchedAt)
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p.HasImage, p.HasIcon = len(p.Image) > 0, len(p.Icon) > 0
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return err
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}
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// PruneLinkPreviews forgets previews older than the given time (they are fetched again when needed).
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func (s *Store) PruneLinkPreviews(olderThan time.Time) error {
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_, err := s.db.Exec(`DELETE FROM link_previews WHERE fetched_at < ?`, olderThan.UTC().Format(time.RFC3339))
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return err
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}
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