@lankajs/plugin-prefetch

⬡ plugin · Network priority ladder

SSE > request > route chunk > prefetch — a rule the code enforces.

A core capability core does not implement itself. Registered with use(), then called by core. peerDependencies: lanka is mandatory.

Runs in: the browser, node and React Native — everywhere.

How to use it: GUIDE.md — the user guide, with examples. How to change it: SKILL.md.

Extension point

Plugs into:

use(plugin) · the instance's observable in-flight counter

Contents

• LankaIntentPrefetch — short-lived buffer: claim, freshness fences, TTL, eviction
• LankaChunkPreload — chunk sweeping with its own counter and expirable gates
• LankaDataWarmup — batched data warm-up with a ceiling on waiting for silence

The ladder

SSE  >  ordinary request  >  route chunk  >  data warm-up  >  intent buffer

Three tiers, three counters — not duplication

The request counter lives in core: there is one send point and the accounting belongs there. The chunk counter lives here because a chunk is pulled by a dynamic import() and is invisible to the request layer; without it, data warm-up would read the wire as quiet mid-sweep and "code first, then data" would rest on a head start rather than a gate.

The intent buffer counts its OWN in-flight requests and SUBTRACTS them from the total. Without that it would see its own request as foreign traffic after the first warm-up and stop itself — permanently and silently.

The tiers also differ by consumer: data warm-up must yield to chunks, the intent buffer must not. It fires on a confirmed gesture toward a known screen and DISCARDS rather than defers; letting a speculative background chunk suppress it would trade a certain win for a guess.

Every gate is escapable

Gates EXPIRE, waiting for silence has a CEILING, and a platform that never reported its visibility is not believed. An absolute gate switches the service off forever on one unlucky moment: a pause whose release never arrives, a connection read as slow in the one second that mattered, a start before the router published its routes — all invisible in a desktop browser and ordinary inside a mobile client.

A buffer, not a cache

Entries live seconds and are read once, so there is no invalidation bus and no way to get it wrong. A live event always beats a warmed copy, through domain fences counted by a COUNTER rather than a list of touched entities: guessing which entry went stale is exactly the guess that cannot be made safely. A redundant invalidation costs one ordinary request.

Repository map: ../../README.md