Here we adjust the ForEachNodeCached graph DB method to pass in a node's
addresses into the provided call-back if requested. This will allow us
to improve the performance of node/channel iteration in the autopilot
subserver.
In preparation for removing the ForEachNode/ForEachChannel call pattern,
we refactor the autopilot subserver by simplifying the `ChannelEdge`
such that it no longer returns the `Node` type which has a
`ForEachChannel` method on it. The aim is to completely remove the
`ForEachChannel` usage.
In this commit, we move the serialisation details of a channel's
features to the DB layer and change the `models` field to instead use a
more useful `*lnwire.FeatureVector` type.
This makes the features easier to work with and moves the serialisation
to where it is actually used.
In this commit, we unify how all unit tests that make use of the graph
create their test ChannelGraph instance. This will make it easier to
ensure that once we plug in different graph DB implementations, that all
unit tests are run against all variants of the graph DB.
With this commit, `NewChannelGraph` is mainly only called via
`MakeTestGraph` for all tests _except_ for `TestGraphLoading` which
needs to be able to reload a ChannelGraph with the same backend. This
will be addressed in a follow-up commit once more helpers are defined.
Note that in all previous packages where we created a test graph using
`kvdb.GetBoltBackend`, we now need to add a `TestMain` function with a
call to `kvdb.RunTest` since the `MakeTestGraph` helper uses
`GetTestBackend` instead of `kvdb.GetBoltBackend` which requires an
embedded postgres instance to be running.
Since we have not removed all call-sites that make use of this
parameter, we can remove it. This helps hide DB-specific details from
the interface we will introduce for the graph store.
The `GraphSource` interface in the `autopilot` package is directly
implemented by the `graphdb.KVStore` and so we will eventually thread
contexts through to this interface. So in this commit, we start updating
the autopilot system to thread contexts through in preparation for
passing the context through to any calls made to the GraphSource.
Two context.TODOs are added here which will be addressed in follow up
commits.
We plan to later on add an option for a remote graph source which will
be managed from the ChannelGraph. In such a set-up, a node would rely on
the remote graph source for graph updates instead of from gossip sync.
In this scenario, however, our topology subscription logic should still
notify clients of all updates and so it makes more sense to have the
logic as part of the ChannelGraph so that we can send updates we receive
from the remote graph.
We do this in preparation for moving channel cache population logic out
of the constructor and into the Start method. We also will later on
(when topology subscription is moved to the ChannelGraph), have a
goroutine that will need to be kicked off and stopped.
And use this struct to pass NewChannelGraph anything it needs to be able
to init the KVStore that it houses. This will allow us to add
ChannelGraph specific options.
Define a new GraphSource interface that describes the access required by
the autopilot server. Let its constructor take this interface instead of
a raw pointer to the graphdb.ChannelGraph.
Introduce a new type for testing code so the main databaseChannelGraph
type does not need to make various write calls to the
`graphdb.ChannelGraph` but the new testDBGraph type still can for tests.
This is a pure code move commit where we move any code that is only ever
used by tests to test files. Many of the calls to the
graphdb.ChannelGraph pointer are only coming from tests code.
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.
In preparation for adding a clean Graph DB interface, we create a
version of FetchLightningNode that doesnt allow a caller to provide in a
transaction.
Finally, The LightningNode object is removed from ChannelEdgePolicy.
This is a step towards letting ChannelEdgePolicy reflect exactly the
schema that is on disk.
This is also nice because the `Node` object is not necessarily always
required when the ChannelEdgePolicy is loaded from the DB, so now it
only get's loaded when needed.
