Re-inserting a card that has already been imported produced a folder full of
`-1` copies. Both halves of the placement logic treated a taken name as a
collision to rename around, which is right for the case they were written for
— two cameras both writing IMG_0001.CR3 — and exactly wrong for the far more
common one, where the taken name is the same photograph.
Locally this cannot be answered from the catalog. On a library whose catalog
describes a *server*, a file sitting in the local destination has no row to be
found by, so the only way to know whether it has already been copied is to
look. The destination folder is listed once per folder rather than probed per
file: a card is two thousand frames landing in a handful of days.
Remotely the same question is one PROPFIND that was already being made to
resolve the name, so `upload_original` now returns `Placed::AlreadyThere`
instead of inventing a second copy of work that is already safe. The count is
reported apart from `uploaded`, because "12 already on the server" and "12
uploaded" are different answers to whether this run backed anything up — and
apart from the local duplicate count, because these files *were* copied here.
Name plus length decides it, not a digest: this runs before any transfer, and
hashing to answer it would read the whole card to avoid reading the whole card.
A camera reusing a filename after IMG_9999 writes a different number of bytes
essentially always, which leaves the rename for the case it is really for. The
digest tier still catches the same frame under a different name.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Distinct from a scan, and the distinction is the whole reason the crate
exists: a scan catalogues files where they already are, where an import moves
them from a card into the library. A scan that fails halfway has read
nothing; an import that fails halfway has written something.
So the failure paths are the design. Bytes stream at 1 MiB and are hashed on
the way past, so an 80 MB RAW never sits in memory. The second destination
(FR-CAT-10's backup copy) is written from the same read rather than copied
from the primary afterwards — a backup made by re-reading the primary would
inherit a bad write rather than catch it, and re-reading the card doubles the
wear on the one copy that still exists. Verification re-reads the
destination, because hashing what is still in memory would pass on a full
disk, a dying card and a truncated write alike. Anything that fails past the
point of creating the file takes the file back, or the next scan catalogues a
truncated RAW as though it were fine.
Three things the crate refuses to know. It never deletes from the card: a
move-import records what is now redundant and a separate retire() does the
deleting, because on a syncing library "safe" means the upload was confirmed
(FR-NC-7b). It does not decode, so capture metadata arrives through a probe
and a card of unreadable files costs no demosaic. And it does not know what a
duplicate is, since that is a catalog query — FR-CAT-11's two tiers arrive as
one closure asked twice, once before any transfer and once with the digest.
Camera serial would be the stronger metadata key and is absent, because
nothing in the tree reads it yet; make and model plus capture time and the
original filename is what is available, and the digest tier covers the gap.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>