DOM work cannot leave the main thread -- a worker has no document, and
nodes are not transferable -- so a card can never be compiled elsewhere.
It can be compiled *earlier*. The page already prefetches the next page's
JSON and warms its thumbnails; this does the same for the cards those
items will need, building and binding them while the browser is idle and
handing them over ready when the reader arrives.
Alongside that, three things that keep a frame from being held too long,
which is what smoothness actually reduces to when the work has nowhere
else to go:
Mounting and filling are drained against a 4ms budget rather than all at
once. Filling in one pass was a regression I introduced with the fling
deferral: it moved the stall from during the fling to the end of it.
A frame's mounts go into a DocumentFragment and enter the document in one
insertion, with filling afterwards so nothing reads layout mid-insert.
The pool is topped up with card shells during idle, so a mount during a
scroll is a rebind and not a construction: cards built mid-scroll fell
from 24 to 5 across profiling runs.
Also reverted, with its numbers kept in a comment: narrowing the overscan
during a fling. It reads like an obvious saving and measures as the
opposite -- a tight window makes cards leave and re-enter it, and mount
churn went from 88 to 155 with blocked time from 3.6s to 4.3s.
What this does not do is reduce total blocked time. Roughly three
quarters of it is browser style, layout, paint and decode for each card
shown, which no amount of scheduling removes. The deep stalls get
shorter; the thread stays busy.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QBDkEXP4htyXTCZUwMLphd
Profiling the reported stutter on a fixed 400-card grid: 30 cards mounted
during one fast scroll, 693ms of blocked main thread -- about 23ms per
card. Building the card is 15.6ms of that. The rest is what a mount sets
off: a thumbnail request and decode, the height correction its load
triggers, a forced layout to measure the title, and an /api/resolve call
that runs yt-dlp on the server. Measured separately, a single fast scroll
fired twelve of those, peaking at nine a second, for videos the reader
never stopped on.
None of it is work anyone asked for while the list is moving. So a mount
during a fling now only places the card: right size, right position, text
and heart in place, so the grid and the scrollbar stay exactly correct.
Everything that costs waits 140ms for the scroll to settle, and then runs
only for the cards still on screen. Whatever was scrolled past is
unmounted having cost almost nothing.
The threshold is 1600px/s, well above a deliberate scroll, so reading at
a normal pace behaves as it did. The visible trade is that flinging
through a long list shows card text over an empty thumbnail box until you
slow down.
Roughly half the blocked time was browser style, layout, paint and decode
that no amount of restructuring removes -- this avoids provoking that work
for cards nobody looks at, rather than making it cheaper.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QBDkEXP4htyXTCZUwMLphd
A second review pass over the pool. All three are the same shape: state
or a listener outliving the video it belonged to.
attachProxyFallback replaces whatever fallback an image currently has,
so a call arriving late -- a race hitting its patience timeout after the
card was recycled -- took away the live listener and left a dead one, and
the new video's thumbnail would then fail with nothing behind it. This
one was self-inflicted: the detach came in last round to stop the
listeners accumulating, and introduced the clobber. It is token-guarded
now, like every other path that can arrive late.
The favourite pop is cleared by animationend, which never fires on a card
release() has already detached -- detached elements run no animations. So
the class rode into the pool and replayed on the next video the card
showed. Favourite something and flick-scroll to see it.
And withOrigin compared a token that dataset reports as undefined for an
unstamped card, which matched every unstamped card instead of none --
failing open in the guard whose whole purpose is noticing that the grid
has recycled the card out from under the player.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QBDkEXP4htyXTCZUwMLphd
Scrolling the grid did nothing but destroy cards and build near-identical
ones back: a template string parsed as innerHTML, ten querySelectors, and
a listener per interactive element, every time a card entered the window.
The virtualizer now keeps a pool and rebinds a card it already has --
18us against 136us to build one, and 74-83% of mounts are served from it.
Two things had to change first. Nothing on a card may close over the
video it is showing, because the card outlives the video, so every
interaction moved to one delegated listener per event type on the grid.
And every card now has the same shape whatever it shows: the optional
parts are always present and hidden when unused, so any pooled card fits
any video. That needed a global [hidden] rule, since .live-badge and
.video-tags carry their own display.
The rest is the release path, which is where this design lives or dies.
A thumbnail carries a generation, so a race or a proxy fallback settling
after the card moved on cannot paint over the video now showing. The
player stamps the card it was opened from, so a recycled element stops
answering for it. The reveal handler, the entrance-animation listener and
the hover preview are all taken back off. Anything missed here surfaces
as one video's title, thumbnail or heart on another video's card, which
is what the smoke suite scrolls back and forth to catch.
Two incidental fixes found while measuring: bindCard no longer writes a
data-tag per tag button (dataset is a proxy, and that alone cost more
than the rest of a rebind put together -- the handler reads the label off
the button), and favorites.has no longer parses a URL for every card that
isn't a favorite by key.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QBDkEXP4htyXTCZUwMLphd
The same video reaches this client under two identities: saved from a
card it carries the server's id, imported from a Hot Tub backup it
carries only its URL. indexOfEntry already matched on either, but the
grid card and the player asked only whether the key was known -- so an
imported favorite left its own listing card, and the player, showing an
empty heart. All three surfaces now ask one question.
Once matched, the listing's copy is the better one: it has the id the
cards key on, and a thumbnail URL that hasn't been sitting in
localStorage since whenever the backup was taken. So a page of listing
videos rewrites the favorites it matches, keeping only the date each was
first saved -- the one fact the listing doesn't know, and the one the
sort depends on. Nothing is written when nothing differs.
Both identity sets now come from one cache dropped on write, since this
is read once per card built and per layout probe, and each read was
re-parsing the whole favorites list out of localStorage.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QBDkEXP4htyXTCZUwMLphd
A thumbnail used to try the provider and only ask /api/image once that
had failed, so every hotlink-blocked host cost a wasted request per card
before anything appeared. Both routes now go out together for the first
thumbnail of a host, and the rest of the batch waits on that one answer
rather than each rediscovering it. Speed decides which image is shown;
capability decides what the host is remembered as, since the proxy tends
to win first contact merely for being same-origin -- pinning a host to it
over that would push a whole page of thumbnails through our own server.
Playback asks the same question, but per video and at play time: one
provider can spread its media over several CDNs, so there is nothing
useful to pre-compute, and the old per-card probe answered for whichever
card happened to scroll past. The direct route is now tested alongside
the proxied playback and takes over if it answers before a frame is
decoded. Whatever loses is cancelled -- the token guards stopped stale
callbacks but left their requests running, so the losing route kept
pulling bytes and the server kept an upstream connection open for them.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QBDkEXP4htyXTCZUwMLphd
Favorites now carry `favoriteDate`. Ones saved before this had no way of
knowing when they were saved, so they are all stamped with the moment the
client first reads them -- they sort together as one batch, at the point
favorites learned to keep dates. An import brings the date the other client
recorded instead, so a restored library keeps its history.
The bar used to build a card per favorite, which an import of several
hundred made an expensive way to open the app. It now renders a screenful
and appends more as the strip is scrolled.
"Browse all" turns the whole grid into favorites: the same cards, the same
virtualized masonry, the same infinite scroll and reels mode as a channel
listing -- App.videos.loadVideos simply pages out of localStorage instead of
the server while that view is open. Sort applies to the bar and the grid
together: recently added (default), oldest, title, longest, shortest, and a
shuffle for rediscovering a long list.
Tests (scratchpad): dates backfilled onto undated favorites, the bar paging
as it scrolls rather than building every card, the grid paging to the full
list with zero server calls, each sort order reordering it, and the way back
to the channel listing. Also measured: 515 imported favorites load with the
page responsive and 24 bar cards built.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QBDkEXP4htyXTCZUwMLphd
Settings gains a file picker that reads an exported Hot Tub database and
merges its favorites into this client's. The file never leaves the device:
sqlite.js is a small read-only reader -- header, schema, table b-trees,
record decoding, and the overflow pages that real rows here spill onto --
which is all it takes to walk one table, and avoids putting a wasm SQLite
behind a CDN fetch.
The two sides don't agree on what identifies a video. The app keys one by a
hash it computes locally (a 64-hex string); the server, and so this client,
keys it as something like "reddit-1rdudss". So the merge matches on
normalized URL: entries already saved here are left exactly as they are,
keeping the server id that makes a listing card's heart light up, and only
genuinely new videos are appended.
That means an imported favorite has no server id, so hearts now also match
by URL (`data-fav-url` on the card, feed slide and favorites bar). Without
it an imported favorite would look unsaved on its own card, and clicking
the heart would file a second copy of the same video.
Only the columns a favorite needs are read. `allFormats` is deliberately
left behind: it holds resolved, signed URLs, which is exactly what
favorites must not store (they expire -- see App.favorites.normalize).
Tests (scratchpad): the reader checked against Python's sqlite3 on a real
12MB backup -- table list, every table's row count, all 515 favorites with
their fields and order, and the 25 longest records byte-for-byte, which is
where a wrong overflow split shows up; and the Settings control driven
end-to-end, covering the merge, an existing favorite keeping its id, a
re-import adding nothing, and a listing card recognising an imported
favorite and unfavoriting it cleanly.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QBDkEXP4htyXTCZUwMLphd
Two costs sat in front of every video: a TLS handshake per upstream request,
and a round trip spent asking the proxy what kind of file it was about to
play.
The session cache was a thread-local, which never once hit -- the server
gives each connection a fresh thread, so every request found empty storage
and built a session, and with it a new connection to the CDN. Instrumented,
that was one session per request; a video is dozens of range requests and an
HLS stream one per segment. Sessions now live in a shared pool, checked out
for a request and returned when its response closes (for a streamed body,
after the last byte), so the connection stays warm. Measured against a
nearby CDN: 32-45ms per request becomes 9-11ms.
The player then HEADed the proxy before playback to sniff a content type --
and that HEAD ran a full upstream GET server-side, so two connections were
opened before the first byte of video was asked for. It now sniffs only when
neither the URL's extension nor yt-dlp's `protocol` says what the source is,
which is nearly never; `protocol` is newly carried through /api/resolve for
exactly this. A HEAD that does still happen asks upstream for one byte and
restates the 206 as a 200 describing the whole resource.
`format_note` joins the resolved fields too: the quality menu has been
reading it since 52d7802, but the backend was dropping it, so no note could
ever have been shown.
Tests (scratchpad, headless): sessions reused across requests, never shared
by two at once, returned after a client aborts mid-stream; HEAD probes one
byte while ranged and plain GETs are byte-identical; no HEAD for an mp4 or a
protocol-bearing URL, and one for a URL with neither.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QBDkEXP4htyXTCZUwMLphd
Some channels hand back the media URL itself as an item's url. Since the
favorites fix, opening one of those sent it to /api/resolve first, so
yt-dlp fetched the media just to report the URL we already had. On a
signed link (`?secure=<ts>-<token>`) that is a second request against
something that may be single-use or IP-bound, and the request that
matters -- the playback fetch -- is then refused. Such URLs now play
directly, with no resolve round trip, as they did before.
Alongside that, three things that make expiry survivable:
/api/stream, after its existing referer-less retry, now retries a 403
completely bare (Range only). Signed CDN links are routinely served to a
plain browser request and refused when it carries extras -- a
`Sec-Fetch-Mode: navigate` on a media subresource, say, which is what
yt-dlp's generic extractor hands back and no real player would send.
When every source fails, the player re-resolves once and retries instead
of giving up, since the likeliest cause is that signed URLs went stale in
a long-open tab rather than the video being gone. A manual quality pick
is dropped for that retry, as it names one of the URLs that just failed.
Favorites stored by older versions still carry a `meta` blob of resolved
formats, long expired; it's now stripped on read so nothing can reach for
one.
Verified: a favorite whose url is a .mp4 plays with zero /api/resolve
calls, straight from that URL; playback, prefetch, feed paging, HUD,
rotation, momentum and the version check all still pass.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QBDkEXP4htyXTCZUwMLphd
A page used to be requested at the moment the reader hit the bottom, so
the cards that appeared were empty frames filling in as their thumbnails
arrived. Now the next page is fetched as soon as the current one renders
and its thumbnails are decoded off-screen (low priority, started on an
idle callback, so warming never competes with what's on screen), then
held until the second-to-last row comes into view -- at which point the
cards appear already finished, and the page after that starts loading.
The two loaders are split into fetch-a-batch and commit-a-batch so the
prefetcher and the on-demand path share them; a held batch is dropped
when the result set changes (search, channel, filters).
Three things this surfaced, all handled:
loadVideos awaited the in-flight prefetch before raising state.isLoading,
so every caller that arrived meanwhile sailed past the guard and started
a duplicate page load, each one re-filling the viewport and calling back
in. On a short desktop page that amplified until the tab stopped
responding. A guard now covers the whole call.
The reveal test can't be "the topmost visible card is in the last two
rows": a desktop viewport shows several rows at once, so the reader would
reach the end of the list without it ever passing. It's now "the
second-to-last row has come into view", measured against the layout.
The reels feed pulls pages through the same entry point, where the grid's
scroll position means nothing -- it (and the Load more button) now pass
force, which skips the hold.
Verified in headless Chrome: page 2 fetched and all 12 of its thumbnails
warmed while it was still hidden, grid still at 12 cards; revealed on the
second-to-last row (phone: viewport bottom 4337px vs row at 4335px;
desktop 4-col: 1704px vs 1687px) with its images already decoded; feed
paging, search reset, rotation, momentum and playback all still good.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QBDkEXP4htyXTCZUwMLphd
The settle window I added for rotation also ran for every `resize`, and
on a phone the URL bar collapsing during a fast flick is exactly that.
It re-asserted an anchor captured before the flick, so a scrollTo landed
mid-momentum and stopped the scroll dead.
Only a width change (or an orientationchange) can move a card: positions
are absolute pixels in the grid's own space, so a height-only resize
leaves both the layout and the scroll position correct and needs no
restore at all. The one exception kept is a scrollbar appearing on
desktop, which changes the grid's inner width while window.innerWidth
stays put -- that re-packs, but only when the columns actually moved.
Modelled the failure in headless Chrome (height change mid-flick, scroll
continuing): the flick was yanked back 173px before, and now runs on to
where it was headed. Rotation still re-anchors, and a fast scroll with 80
videos loaded holds 60fps (median 16.7ms/frame, max 17.2ms, no frame
over 32ms).
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QBDkEXP4htyXTCZUwMLphd
Favorites persisted the *resolved* stream metadata (resolveAndProbe
mutates video.meta with yt-dlp's CDN format URLs), so a favorite opened
the next day replayed a dead link. They now store only the page URL and
identifying fields, and ignore any stale meta left in localStorage --
playback, download and info re-resolve through the backend, which
resolves a page URL live in /api/stream.
That left the quality switcher empty for anything not yet resolved
(favorites, cards clicked before their hover-resolve landed, feed
slides), so App.videos.ensureFormats now resolves formats once per
session -- cached by video id rather than per object, so any object
describing the same video gets them -- and both the player and the reels
feed rebuild their format menu when they arrive. Playback isn't blocked:
it already starts from the page URL via the proxy.
Rotating a phone also jumped the grid to a completely different place:
the anchor was read inside the resize handler (by which point the
browser has already moved the scroll) and asserted once, and every
re-pack discarded known card heights for the 16:9 placeholder estimate.
The virtualizer now tracks the anchor on every scroll pass, re-asserts
it across a short settling window (ending early on a real gesture), and
remembers each thumbnail's true aspect ratio so a re-pack places cards
at their real heights. Verified in headless Chrome across a
portrait/landscape/portrait cycle: visible videos 37-39 -> 36-40 ->
36-38, against 37-39 -> 34-37 -> 29-30 before.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QBDkEXP4htyXTCZUwMLphd
Single fullscreen player state everywhere (desktop/Android/iOS/feed) instead
of the old modal-vs-native-fullscreen split, with custom controls: draggable
timeline with buffered range, dynamically-escalating skip buttons (double-tap
zones too), per-video format switching, favorites, PiP with auto-PiP on
backgrounding, volume swipe, TikTok-style HUD auto-hide, and swipe-down/
back-button/close-button dismissal. Reels feed reuses the same skip/format/
PiP logic via the new customPlayer.js shared module.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Move the duration (bottom-right) and uploader (bottom-left) onto the
thumbnail as dark-transparent pills instead of text rows below it, for
both .video-card and .favorite-card. Wrap the thumbnail in .video-thumb
to anchor the overlays; uploader stays clickable and truncates with
ellipsis. Favorite cards now show duration too (was stored, never shown).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Layered progressive polish on the warm classic + brass theme:
- Card entrance animation on first mount (virtualizer-aware)
- Cursor-tracking brass spotlight border on cards
- Thumbnail skeleton shimmer until the poster paints
- Hover video preview after a short dwell (only when formats resolved)
- View Transition + blurred-poster ambient backdrop on player open
- Favorite heart pop + expanding ring on add
- ⌘K command palette (search, theme, density, reels, source/channel)
- Scroll-progress bar + back-to-top FAB
- Grid density toggle (comfortable/compact)
- Reels HUD: serif title, brass scrubber, muted-state pulse
All new motion respects prefers-reduced-motion; no JS/HTML structure
changes to the core grid/feed. New glue lives in frontend/js/enhance.js.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
