A shelf book can be requested as an ebook, an audiobook or both (one request per format), and each request is checked against its own library, source priority list and format guard. Ranking within a source prefers the most downloaded copy, then size, and one m4b is preferred to a set of chapter files unless it is much smaller than the other copies. Soulseek peers are ranked by free slot, queue length and speed.
Automatic downloads refuse multi-book packs, sequels and other works named in the title, study guides, abridged or dramatised versions, two-in-one titles, releases in a language the requester didn't ask for, and an archive for an audiobook request.
Matching folds accents on both sides, drops an alternate title for the search and the match, and reads small numbers the same in any form. AudiobookBay releases with no author in the listing title are judged on the authors credited on the detail page.
I went through what Shelfmark does per search and per cover and measured
the pieces that showed up. Four of them are cheap to fix, so this is one
PR. Shelfmark runs on a single gevent worker, so any of these blocks
every other request while it runs, and I'm assuming a lot of people run
it on small hardware (a Pi, say).
Cover cache. Every cache hit rewrote the whole `cache_index.json` just
to bump the entry's last-access time. On my box that is 3.7 ms of CPU
per hit at 500 entries and about 100 ms at 15,000 (2.2 MB written each
time), and a results page asks for around 40 covers. The access time now
stays in memory and the index is written at most every 30 seconds, or
whenever something else saves it. A crash inside that window loses some
access times, which only changes eviction order.
Settings reload. `config.refresh()` rebuilt the cache by reading and
parsing a tab's JSON file once per field, so about 250 parses per
refresh, 100 ms of CPU, and the metadata search, providers and config
routes each trigger it. It now reads each file once per rebuild (several
tabs share `settings.json`, so the memo is keyed on the file path).
Library match. When the library check is on, each search result is
compared against every library entry, and the title was split into words
again for every entry. The words are now computed once per result. I
measured 33 ms per result at 5,000 library entries and 106 ms at 20,000,
which is a second or more per page of 40 results. The matching itself is
unchanged.
Cover URL probe. `is_covers_cache_enabled()` creates and deletes a file
in the config directory to check it is writable, and it runs for every
cover, queue task and history row. The answer is remembered for 60
seconds. The probe is 0.045 ms on its own, but it is called a few
hundred times per request in the worst case.
Each change has a test that fails without it (call counts on the index
saves, file opens during a refresh, tokenisation calls, and probe
calls). Ruff, basedpyright on the changed files and the non-e2e suite
pass. The timings are from a dev machine with an empty config, so the
real numbers depend on cache and library size.
Per discussion #1372, where you said you were fine with this specific
implementation: check whether metadata.db exists, read it if so, and
show a check mark saying the book is already there.
Searching for a book you already own gives no hint that you own it, so
the easiest way to end up with a second copy is to not remember you have
the first. This reads a Calibre `metadata.db`, read only, and marks
matching results with an **In library** badge in the card, list and
compact views and in the details dialog.
Off by default. It sits in Settings, General beside the existing Library
URL, with a test button that reports how many books it indexed. No HTTP
call, no token, nothing written back.
Matching runs most to least confident: a shared external id, then an
ISBN compared in both ISBN-10 and ISBN-13 form, then fuzzy title tokens
plus the author surname. The check fails open, so an unreadable database
degrades the badge and never blocks a search, and entries are cached for
ten minutes with an early refresh when the file changes, so a large
library costs one read rather than one per search.
`text_match.py` is new and shared by the index and the provider, so
title, author and ISBN matching stays consistent in one place.
## On the provider interface
`library_index` talks only to a `LibraryProvider` protocol and knows
nothing about Calibre. That is deliberate but it is not speculative
generality, it is what let me send you the Calibre half on its own: I
run an Audiobookshelf provider on the same interface in my fork, which
is where the audiobook side of the badge comes from. I have left that
out because it is a new service integration rather than something
already in the codebase, which is the line your non-goals draw. Happy to
send it separately if you ever want it, and equally happy for the answer
to be no.
Adding a library is a module with the `LibraryProvider` shape plus one
line in `all_providers()`.
## Verification
- `tests/core/test_library_index.py`: id, ISBN and fuzzy matching,
per-content-type provider selection, fail-open on provider errors,
stale-cache reuse, TTL and fingerprint refresh, per-provider cache
isolation, and the test-connection path including unsaved form values.
- `tests/core/test_text_match.py`: ISBN variants and token matching.
- `src/frontend/src/tests/libraryBadge.test.ts` and the added cases in
`bookTransformers.test.ts`.
- Python suite (3269) and frontend suite (206) green, plus ruff, ruff
format, basedpyright, vulture, tsc, oxlint, oxfmt and the production
build.