Instead of having a routing database, and an addresses database,
consolidate that in a single database called `node.db`.
We also simplify database access, by providing a single type for opening
the database, and use traits to access the various functions.
We create a new `seed::Store` that has seed-related methods split out of
the `address::Store`.
Note that tracking is still in its own database currently, as it isn't
ephemeral state. This makes it easy to delete the new `node.db` without
risk of losing any important information.
To avoid renaming all database methods, we create a `Stores` wrapper
that allows us to access routing, addresses, seeds etc. without type
ambiguity.
This is a breaking change and requires `addresses.db` and `routing.db`
to be deleted.
Previously, we would always ask nodes for messages from one hour ago.
This meant that we could miss messages if our node was offline for more
than an hour. This change uses a variable backlog by checking the
timestamp of the last gossip message we received.
Instead of storing received gossip messages in an in-memory `BTreeMap`,
we persist them to the database (`addresses.db`). There are two reasons
for this:
1. Node restarts do not wipe the state, meaning that it is much less
likely that some gossip message will get lost before reaching all
nodes.
2. This will allow us in the next commit to know how far behind we are
after a restart, to be able to request the correct time range of
gossip messages that we missed while offline.
Note that we now share the addresses.db file between two connections and
stores, which we don't do anywhere else. Having multiple connections to
the same database is fine, but the way we're having to do it is a bit
awkward. In a future patch, we could pull out the database schema from the
`address` module and rename the database to make things clearer.
cloudhead