Filespooler

Job task queue for very specific niche cases. Specifically names NNCP users as one of those cases.

Has plain old folders which store a counter file and a directory of incoming request packet files.

Packet files are checked for a sequence number and compared against the counter file. Any jobs lower than the counter are discarded, higher than the counter are left alone, and a job equal to the counter is processed (then the counter is executed and the process repeats.)

The stated purpose is for unpacking incremental backups which has to be performed in a specific order even though the individual backups may arrive out of order.

A lockfile is also used presumably to avoid filespooler commands trampling over the same queue.

Job files must be named `fspl-*.fspl` so temp file can also live in the queue folder.

Append-only queue: the counter and lockfile are omitted; process commands are disabled but you can still use commands to insert new packets.

commands are around inserting jobs, messing with the sequence file, forcing jobs to run, creating packets to trigger jobs on another box... there are a lot but I'm too lazy to bother listing them all.