When you first boot, if you try talk to someone before your azimuth is
up-to-date (for example by import), then if they've ever breached
(twice) then you'll get breach notification, cancelling your message.
This changes is it so that if we haven't heard anything about this ship,
we don't signal a breach.
The implementation complexity is primarily because we need
eth-watcher/azimuth-tracker to produce an update of a list instead of a
list of updates. This way, Jael can keep a "state as of the beginning
of this move" variable to check when deciding whether to signal a
breach.
Previously, when the refresh-rate timer activated, and the thread from
the previous activation was still running, we would kill it and start
a new one. For low refresh rates, on slower machines, nodes, or network
connections, this could cause the update to never conclude.
Here we add a timeout-time to eth-watcher's config. If the refresh-rate
timer activates, and a thread exists, but hasn't been running for at
least the specified timeout-time yet, we simply take no action, and wait
for the next refresh timer.
Note that we opted for "at least timeout-time", instead of killing &
restarting directly after the specified timeout-time has passed, to
avoid having to handle an extra timer flow.
In the +on-load logic, we configure the timeout-time for existing
watchdogs as six times the refresh-rate. We want to set
azimuth-tracker's timeout-time to ~m30, and don't care much about other,
less-likely-to-be-active use cases of eth-watcher.
Instead of providing a (unit path), allows for (list path), which better
supports the "update to path and subpath cases".
For example, if /things wants updates about everything, and
/things/specific wants updates about the specific thing, they'll both
need to receive a %fact when the specific thing changes.
Previously, these would have been two separate moves. Now, gall handles
the multi-targeting for you.
Re-implements the behavior of the previous azimuth-tracker as an app
that pokes and peers eth-watcher. Should have maintained identical
outward semantics to the original.
Uses the logic existing in azimuth-tracker to implement a new
eth-watcher, which can look at Ethereum nodes for _any_ events, as
opposed to exclusively a subset of the Azimuth contract's events.
Azimuth-tracker will be reimplemented as a dependent of this in
forthcoming commits.
