diff options
Diffstat (limited to 'src/thread-prefetch.js')
| -rw-r--r-- | src/thread-prefetch.js | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/src/thread-prefetch.js b/src/thread-prefetch.js index 6d34db6..c21289c 100644 --- a/src/thread-prefetch.js +++ b/src/thread-prefetch.js @@ -1,5 +1,9 @@ // Dwell is measured on mounted rows, including posts taller than the viewport. // Sampling also catches fast movement within a large post (IO alone cannot). +// A post read for half a second is a post that may be opened: its thread is +// fetched then (it was 1.2 s, which a quick reader beat to the tap), one at +// a time, a dozen a minute. +const DWELL_MS = 600, PER_MINUTE = 12; export function createThreadPrefetch({ load, key, cached, doc = globalThis.document, nav = globalThis.navigator, now = Date.now, schedule = setTimeout, cancel = clearTimeout }) { const seeds = new Map(), dwell = new Map(); @@ -23,12 +27,12 @@ export function createThreadPrefetch({ load, key, cached, doc = globalThis.docum if (!d || Math.abs(r.top - d.top) > 25) d = { since: time, top: r.top }; d.top = r.top; dwell.set(id, d); - if (time - d.since >= 1200) ready.push(seed); + if (time - d.since >= DWELL_MS) ready.push(seed); } for (const id of seeds.keys()) if (!mounted.has(id)) seeds.delete(id); for (const id of dwell.keys()) if (!visible.has(id)) dwell.delete(id); starts = starts.filter((t) => time - t < 60000); - if (!busy && starts.length < 6 && ready.length) { + if (!busy && starts.length < PER_MINUTE && ready.length) { const seed = ready[0], token = generation; busy = true; starts.push(time); // The loader inserts synchronously, so clicks share its in-flight work. |