- Shipped
- August 6, 2026 at 8:45 PM UTC
- Author
- Kamo
- Commit
- 0eda67f
Attachments wrote their own "<imgId>/<fileName>" object on every upload, bypassing the content-addressed store entirely — the same logo-draft.png attached three times in one conversation occupied three objects. Uploads now hash into a shared ImgDat, so identical content is stored once no matter how often it is attached, and an attachment that matches a document already in the system costs no storage at all. The Img row stays per-attachment: it carries the conversation, uploader and revocation state, and it is still what access is checked against. Only the bytes are shared. Reads resolve the content-addressed key when the row has a dat and fall back to the legacy per-upload object when it does not, so attachments predating this keep working — including any written by an instance that has not rolled over yet. ChatAttachmentDedupBackfill folds those legacy attachments in on startup: it selects only rows with a null dat and sets that dat last, so it is idempotent, self-healing across the rollout, and a failure on one row leaves it on the still-working legacy path rather than failing startup. Legacy objects are left in place; nothing deletes from MinIO.