simon/jacuzzi
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Reuse upstream connections, and stop sniffing what we already know

Browse Source 
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
This commit is contained in:
Simon
2026-09-05 23:27:24 +00:00
parent 52d7802491
commit b48d7aa161
5 changed files with 184 additions and 23 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
frontend/js/player.js
View File

@@ -734,9 +734,9 @@ App.player = App.player || {};
};
let streamUrl = entry.direct ? resolved.url : App.videos.buildStreamUrlFromSource(resolved);
let isHls = /\.m3u8($|\?)/i.test(resolved.url);
let isDirectMedia = /\.(mp4|m4v|m4s|webm|ts|mov)($|\?)/i.test(resolved.url);
if (resolved.isLive) { isHls = true; isDirectMedia = false; }
const kind = App.videos.classifySource(resolved);
let isHls = kind.isHls;
let isDirectMedia = kind.isDirectMedia;
video.onerror = null;
if (state.hlsPlayer) {
@@ -749,7 +749,11 @@ App.player = App.player || {};
video.removeAttribute('src');
video.load();
if (!isHls && !entry.direct) {
// Last resort only: a HEAD through the proxy is a whole upstream
// connection (handshake included) before the first byte of video is
// ever requested, so it runs only when neither the URL nor the
// extractor's protocol says what this source is.
if (!isHls && !isDirectMedia && !entry.direct) {
try {
const headResp = await fetch(streamUrl, { method: 'HEAD' });
if (token !== cp.attemptToken) return;