In this commit, we add a bunch of graph methods to the GraphSource, let
DBSource implement it and then we use the graph source for these
methods for the GetNodeInfo, VerifyMessage, DescribeGraph,
GetNodeMetrics, GetChanInfo and GetNodeInfo RPC calls along with peer
alias lookup.
Define a new GraphSource interface required by the invoicerpc server and
remove its access to the graphdb.ChannelGraph pointer. Add the new
invoicesrpc.GraphSource interface to the GraphSource interface
and let DBSource implement it.
Since the GraphSource interface may be satisfied by an RPC connection,
it is best practice to pass a context through to any call in the
interface.
The ChanGraphSource implementation, which uses a kvdb backend, does not
make use of the ctx. Any call-sites are for now given a `context.TODO()`
which will all be addressed in follow up commits.
In this commit, we take the existing graphsession.ReadyOnlyGraph
interface and remove its usage of a kvdb.RTx and replace it with a more
abstract `RTx` interface type.
The new GraphSource interface is expanded to include the
graphsession.ReadOnlyGraph interface and the implementation of it,
DBSource, is expanded to include the new methods. It converts the
given RTx to the underlying kvdb read transaction where needed.
This commit adds a new GraphSources interface that LND requires for
graph related read-only queries. As of this commit, the interface is
empty but it will be populated over the next couple of commits. We add
an implementation of this interface backed by a pointer to a
graphdb.ChannelGraph.
The infrustructure is put into place so that the GraphSoure provided to
LND can be overridden by a caller of the lnd.Main function. By default,
LND will satisfy the interface itself via the new `graphsource.DBSource`
struct.
For consistency in the graphsessoin.graph interface, we let the
FetchNodeFeatures method take a read transaction just like the
ForEachNodeDirectedChannel. This is nice because then all calls in the
same pathfinding transaction use the same read transaction.
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.
We also now use the graph DB's own optional functions. An instance of
the graph is currently still passed to the channeldb's
`CreateWithBackend` function. This will be removed in a later commit
once the two have been completely disjoint.
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`.
We have the same helpers for writing and reading a wire.Outpoint type
defined separately in a couple places. We will want to use these from
the graph db package soon though so instead of defining them again
there, this commit unifies things and creates a single exported set of
helpers. The next commit will make use of these.
In preparation for moving the graph related schema structs to the graph
package in an upcoming commit, we move these methods to the graph
package. The structs we will move make use of these methods but we still
import them from channeldb so as to keep the ReadElement and
WriteElement helpers working as they do today.
In preparation for adding the new ChannelAnnouncement2 message along
with a ChannelAnnouncement interface, we rename the existing message to
ChannelAnnouncement1.
In preparation for adding a new message, AnnounceSignatures2 along with
an AnnounceSignatures interface, we rename the existing message to
AnnounceSignatures1.
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.
