Only write a bridge-stats string if bridge stats have been
initialized. This behavior is similar to dirreq-stats, entry-stats,
etc.
Also add a few unit tests for the bridge-stats code.
This patch separates the generation of a dirreq-stats string from
actually writing it to disk. The new geoip_format_dirreq_stats()
generates a dirreq-stats string that geoip_dirreq_stats_write() writes
to disk. All the state changing (e.g., resetting the dirreq-stats
history and initializing the next measurement interval) takes place in
geoip_dirreq_stats_write(). That allows us to finally test the
dirreq-stats code better.
This lets us make a lot of other stuff const, allows the compiler to
generate (slightly) better code, and will make me get slightly fewer
patches from folks who stick mutable stuff into or_options_t.
const: because not every input is an output!
Instead of answering GETINFO requests about our geoip usage only after
running for 24 hours, this patch makes us answer GETINFO requests
immediately. We still round and quantize as before.
Implements bug2711.
Also, refactor the heck out of the bridge usage formatting code. No
longer should we need to do a generate-parse-and-regenerate cycle to
get the controller string, and that lets us simplify the code a lot.
With this patch we stop scheduling when we should write statistics using a
single timestamp in run_scheduled_events(). Instead, we remember when a
statistics interval starts separately for each statistic type in geoip.c
and rephist.c. Every time run_scheduled_events() tries to write stats to
disk, it learns when it should schedule the next such attempt.
This patch also enables all statistics to be stopped and restarted at a
later time.
This patch comes with a few refactorings, some of which were not easily
doable without the patch.
