_load_server_tsv_with_backup was a near-copy of _load_id_dict_with_backup:
same verify, same fallback, same backup, differing only in the parser and in
having "server_ids" written into its log messages. #94 added the skip-if-
unchanged path to one of them, so server_ids.tsv stayed the one alias file
re-read on every 15 minute tick.
They are one function now, taking the parser as an argument. Removes 51
duplicated lines and leaves no second path to drift.
The reload loop ticks every 900s so a failed download is retried soon, but
STALE_DAYS replaces the files about once a day. Every tick in between
re-read them: blake2b over 50MB, a JSON parse, a 50MB copy to .bak, and a
300k-entry profile rebuild, all to produce the same dicts.
Parsed results are now kept against each file's (mtime_ns, size, inode) and
the backup is written only when the primary has been verified, which is the
point where it is worth keeping as a fallback. A primary that fails drops
its remembered parse so the next tick looks at the file again.
The profile build also ran in merge_reload_into_config, on the reactor
thread, at over a second per cycle. It is built in the thread pool now and
handed in.
A tick with nothing new: 2568ms -> 0.2ms.
Rodrigo Pérez