and the same for ChannelStateDB.FetchChannel. Most of the calls to these
methods provide a `nil` Tx anyways. The only place that currently
provides a non-nil tx is in the `localchans.Manager`. It takes the
transaction provided to the `ForAllOutgoingChannels` callback and passes
it to it's `updateEdge` method. Note, however, that the
`ForAllOutgoingChannels` call is a call to the graph db and the call to
`updateEdge` is a call to the `ChannelStateDB`. There is no reason that
these two calls need to happen under the same transaction as they are
reading from two completely disjoint databases. And so in the effort to
completely split untangle the relationship between the two databases, we
now dont use the same transaction for these two calls.
All the structs defined in the `channeldb/models` package are graph
related. So once we move all the graph CRUD code to the graph package,
it makes sense to have the schema structs there too. So this just moves
the `models` package over to `graph/db/models`.
This commit is a large refactor that moves over various responsibilities
from the ChannelRouter to the graph.Builder. These include all graph
related tasks such as:
- graph pruning
- validation of new network updates & persisting new updates
- notifying topology update clients of any changes.
This is a large commit but:
- many of the files are purely moved from `routing` to `graph`
- the business logic put in the graph Builder is copied exactly as is
from the ChannelRouter with one exception:
- The ChannelRouter just needs to be able to call the Builder's
`ApplyChannelUpdate` method. So this is now exported and provided to
the ChannelRouter as a config option.
- The trickiest part was just moving over the test code since quite a
bit had to be duplicated.
This is preparation for an upcoming commit that will move over various
responsibilities from the ChannelRouter to the graph Builder. So that
that commit can be a pure code-move commit, the template for the new
sub-system is added up front here.
