Introduction

We currently have thousands of statically built pages that need to be populated into the cache handler on startup. This takes about 30-40 seconds in our production instance. This change tries to reduce the time spent registering the initial cache by parallelizing the route population.

Summary

Populate page-cache in parallel instead of sequentially.

Old behavior
Previously, all routes were set one-by-one.

New behavior
Up to os.availableParallelism() pages are now concurrently read from the filesystem and populated into the cache handler.

Changes

• Parallelize initial cache hydration by wrapping route population in p-limit with os.availableParallelism() and awaiting Promise.all, so initial routes/pages are processed concurrently.
• Introduce a promise-backed latch on CacheHandler that guarantees onCreation runs exactly once; #ensureConfigured() now serializes calls while still letting the main set/get/revalidateTag logic run in parallel.
• Preserve previous behavior by resetting the latch if initialization fails, and retain the existing merged-handler guard so repeated calls after the first simply fall through and create a debug log message.

OSS @durchblicker