Return a still-valid upload URL to the pool for future reuse.
The bucket ID or file ID the entry belongs to.
The upload URL entry to return to the pool.
Take an upload URL from the pool, or return null if none are available.
The bucket ID or file ID to look up.
An upload URL entry, or null if the pool is empty for the given key.
Remove all entries from every key in the pool.
Remove a specific upload URL from the pool (e.g. after an upload error).
The bucket ID or file ID the entry belongs to.
The failed upload URL entry to remove.
Manages a pool of reusable upload URLs keyed by bucket ID or file ID. URLs are checked out before an upload, checked back in on success, and evicted on error so they are not reused.