Missing files: detect them, stop offering them, and follow them when they move #121
Merged
bvandeusen
merged 2 commits from 2026-08-06 20:40:39 -04:00
dev into main
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 bvandeusen
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24d330424f |
feat(library): adopt moved files instead of forking their history — #2528
Track identity was file_path, so a file that came back renamed or in a different directory looked like a deletion plus an unrelated new track: the old row kept the like and every play_event while a fresh zero-history row appeared, and nothing connected them. A liked song read as unliked, its play count reset, and Rediscover could offer it as a discovery — silently. Renumbering an album was enough, which is what happened to the operator's copy of Minutes to Midnight. Adoption re-points the existing row's file_path at the new location and clears its missing mark. The normal UpsertTrack then conflicts on file_path and updates THAT row, so the track id survives and likes, plays and playlist memberships travel with it — and clients see an update rather than a delete-and-create, so no cache churn either. Matching is MBID first (identifies the recording, so it survives a re-encode), then file_size + duration_ms for untagged files. Both fingerprint components must be non-zero: duration_ms is 0 when ffprobe failed, and matching 0 against 0 would pair up unrelated broken files. Only rows already marked missing are eligible — a row whose file is present elsewhere is a duplicate, not a move, and re-pointing it would corrupt the copy that still exists. An ambiguous match inserts fresh rather than adopting one arbitrarily: a fork is recoverable later, a wrong merge isn't. Scan is now three phases, and the order is the point. Adoption can only claim a row that is ALREADY marked missing, but reconcile previously ran after processing — so a rename performed while the server was down surfaced the deletion and the addition in the same scan, the new path inserted first, and the fork became permanent. Enumeration is therefore separated from processing so reconcile can run between them: walk (paths only, no tag reads or probes) -> reconcile -> process in walk order. Consequence worth knowing: when reconcile refuses (an absent root, or a reorganisation exceeding the 25% mark cap) adoption cannot fire and renamed files fork as before. That's the pre-#2528 behaviour rather than a new failure, and the warning now names it. The old outer walk-error branch was unreachable — the callback always returned nil, so WalkDir never surfaced an error — and verifyRootsPresent is the real protection, so enumerate counts walk errors instead of pretending to abort on them. |
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bvandeusen
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f6d1cf24f0 |
feat(library): detect missing files and stop offering them — #2523
Nothing in Minstrel ever noticed a deleted file. The walk only visits paths that exist, so a row whose file was gone was never scanned, never errored, never counted — permanently invisible. classifyEvent ignores fsnotify removals by design, and the safety-net scan is the same walk, so it covers additions only. Rows accumulated forever. Found on the operator's library: a completed scan reported skipped=24185 errored=0 while the MBID backfill (which opens files by DB path rather than walking) logged ~40 "no such file or directory" across three reorganised albums. Those rows also kept their pre-#2499 welded genre, which is how this surfaced — the version-stamped tag re-read can only reach files the walk visits. The harm is not cosmetic. tracks is the candidate universe for recommendation.sql / discover.sql / system_mixes.sql and nothing filtered on file existence, so a mix could spend a slot on a track that cannot stream. Marks rather than deletes. A missing file is a claim about the filesystem and the filesystem lies transiently — an unmounted volume, a network blip, a container that started before its media mount attached. Every sweep in internal/gc resolves a truth INSIDE the database and is safe to run blind; this one is not, so no deletion happens here. Three guards refuse to act on ambiguous evidence: every scan root must resolve to a non-empty directory, the walk must have seen at least one file, and one reconcile may newly mark at most 25% of the library. Clearing a mark is never the dangerous direction, so it runs unconditionally — otherwise a library that tripped the cap could never recover once the mount returned. Only a full Scan reconciles. The walk's set of seen paths is the evidence, and ScanFiles has no basis for concluding anything about files it did not look at. Excludes marked tracks from all 13 track-emitting queries (radio x2, system mixes x5, discover x4, most-played x2), the 6 play-history seed picks, and the genre browse axis. Deliberately NOT filtered: the shared ListPlaylistTracks read path, because it also serves user-curated playlists where hiding a track the user added would be wrong — system playlists shed orphans on their next daily rebuild instead. History and the taste profile also keep them: those record the past, and a track you played 200 times still says something about your taste. Reconcile tallies land in scan_runs so a disappearance is visible rather than discovered when a mix comes up short. |