/api/showcase returns a random sample; after enough scrolling, an
unlucky 3-item batch can be entirely in the `seen` Set, which was
flipping `exhausted=true` and surfacing "End." mid-scroll. The
showcase is endless by intent — only a genuinely empty API response
(library has 0 images) should mark it exhausted. Tiny-library
fallback: cap retries at 8 to avoid spinning forever.
Operator-flagged 2026-05-30 (round 3): the all-parallel fetch was fast
but could let later chunks arrive ahead of earlier ones — even when
each chunk is a random sample, that "later chunk loads first" risk made
the load order non-deterministic. And the original goal behind asking
for batching was a faster first-image-on-screen, which neither sequen-
tial nor parallel really addressed cleanly.
Switched the loadInitial flow to a PIPELINE:
- Only one fetch in flight at any moment (in-order arrival, no race).
- The NEXT fetch kicks off as soon as the current one resolves (NOT
after its trickle finishes), so the next RTT overlaps the visible
trickle window — round-trips are hidden behind the animation cadence.
- PAGE 5 → 3 + INITIAL_BATCHES 12 → 20 (total still 60). Smaller chunk
→ first chunk's items appear sooner (a chunk of 3 trickles in 240ms,
well within one RTT, so by the time chunk 2 is in-hand the first
trickle is just finishing).
Trickle, sequence-token guard, and infinite-scroll behaviour unchanged.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Operator-flagged 2026-05-30 (round 2): the batched-loads change improved
consistency but still felt "chunky" — 5 items appeared together, then a
~200 ms API round-trip pause, then another 5. And infinite-scroll fired
too late when a single tall image (long manga page) made one masonry
column much taller than its siblings.
**Cadence (showcase store):**
- Fire all INITIAL_BATCHES fetches in PARALLEL — collapses the per-
batch round-trip gap so all the data arrives in ~1 RTT instead of 12
sequential RTTs.
- Trickle each response's items into images.value one at a time with
APPEND_DELAY_MS = 80ms between each (≈ the MasonryGrid stagger
animation, 70ms). User sees a smooth steady stream.
- fetchPage (the infinite-scroll path) uses the same trickle so its
5-item appends also cascade one-by-one instead of popping together.
- Sequence token guards against a fast shuffle / mount-then-shuffle
interleaving two trickles into the same images.value.
- Dropped useAsyncAction here — the parallel-fetch-then-trickle flow
doesn't fit its single-wrap-call shape cleanly; inline loading/error
state is clearer.
**Infinite-scroll trigger (MasonryGrid):**
- Pass `rootMargin: '2400px'` to useInfiniteScroll (was the 600px
default). The masonry sentinel sits at the bottom of the container,
whose height = MAX(column heights). A tall image in one column pushes
the sentinel ~2× viewport below where the user is actually reading
(the bottom of the SHORTER columns). 2400px ≈ 2-3 screen-heights of
pre-emptive trigger, comfortable for typical tall manga heights.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The showcase-store change in adeee64 didn't actually land — only
gallery.js + ShowcaseView.vue made it into the commit. Without this,
ShowcaseView mounts loadInitial() which doesn't exist yet, so the
showcase blows up. Landing the matching store edit now.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
New composables/useAsyncAction.js owns the loading/error/try-finally
lifecycle. Migrated 11 stores: credentials, downloads, sources, posts
(error=raw) + ml, artistDirectory, tagDirectory, showcase, suggestions,
seriesReader, modal (error=message). The errorAs option preserves each
store's existing error shape so store.error keeps the same type for
components (~50 consumption sites unchanged). Stores whose catch also
reset data (suggestions/seriesReader/modal) clear it upfront instead.
Deliberately NOT migrated (special control flow, would change behavior):
artist (conditional 404 catch + dual loading states), migration (rethrows),
gallery (inflight-id stale-response guard), and the Shape-B no-catch /
loaded-guard / keyed-cache stores.
Net -77 lines.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
bvandeusen
