With the previous commit, the AddNode method was removed and since that
was the only method making use of the ForEachChannel on the
GraphCacheNode interface, we can remove that method. Since the only two
methods left just expose the node's pub key and features, it really is
not required anymore and so the entire thing can be removed along with
the implementation of it.
The AddNode method on the GraphCache calls `AddNodeFeatures` underneath
and then iterates through all the node's persisted channels and adds
them to the cache too via `AddChannel`.
This is, however, not required since at the time the cache is populated
in `NewChannelGraph`, the cache is populated will all persisted nodes
and all persisted channels. Then, once any new channels come in, via
`AddChannelEdge`, they are added to the cache via AddChannel. If any new
nodes come in via `AddLightningNode`, then currently the cache's AddNode
method is called which the both adds the node and again iterates through
all persisted channels and re-adds them to the cache. This is definitely
redundent since the initial cache population and updates via
AddChannelEdge should keep the cache fresh in terms of channels.
So we remove this for 2 reasons: 1) to remove the redundent DB calls and
2) this requires a kvdb.RTx to be passed in to the GraphCache calls
which will make it hard to extract the cache out of the CRUD layer
and be used more generally.
The AddNode method made sense when the cache was first added in the
code-base
[here](369c09be61 (diff-ae36bdb6670644d20c4e43f3a0ed47f71886c2bcdf3cc2937de24315da5dc072R213))
since then during graph cache population, nodes and channels would be
added to the cache in a single DB transaction. This was, however,
changed [later
on](352008a0c2)
to be done in 2 separate DB calls for efficiency reasons.
In this commit, a new NodeRTx interface is added which represents
consistent access to a persisted models.LightningNode. The
ForEachChannel method of the interface gives the caller access to the
node's channels under the same read transaction (if any) that was used
to fetch the node in the first place. The FetchNode method returns
another NodeRTx which again will have the same underlying read
transaction.
The main point of this interface is to provide this consistent access
without needing to expose the `kvdb.RTx` type as a method parameter.
This will then make it much easier in future to add new implementations
of this interface that are backed by other databases (or RPC
connections) where the `kvdb.RTx` type does not apply.
We will make use of the new interface in the `autopilot` package in
upcoming commits in order to remove the `autopilot`'s dependence on the
pointer to the `*graphdb.ChannelGraph` which it has today.
In preparation for moving funding transaction validiation from the
Builder to the Gossiper in later commit, we first convert these graph
Error Codes to normal error variables. This will help make the later
commit a pure code move.
The point of the `graph.Builder`'s `networkHandler` goroutine is to
ensure that certain requests are handled in a synchronous fashion.
However, any requests received on the `networkUpdates` channel, are
currently immediately handled in a goroutine which calls
`handleNetworkUpdate` which calls `processUpdate` before doing topology
notifications. In other words, there is no reason for these
`networkUpdates` to be handled in the `networkHandler` since they are
always handled asynchronously anyways. This design is most likely due to
the fact that originally the gossiper and graph builder code lived in
the same system and so the pattern was copied across.
So in this commit, we just remove the complexity. The only part we need
to spin off in a goroutine is the topology notifications.
In this commit, we remove the `processUpdate` method which handles each
announement type (node, channel, channel update) in a separate switch
case. Each of these cases currently has a non-trivial amount of code.
This commit creates separate methods for each message type we want to
handle instead. This removes a level of indentation and will make things
easier to review when we start editing the code for each handler.
The `netann` package is a more appropriate place for this code to live.
Also, once the funding transaction code is moved out of the
`graph.Builder`, then no `lnwire` validation will occur in the `graph`
package.
This commit does two things:
- removes the concept of allow / deny. Having this in place was a
minor optimization and removing it makes the solution simpler.
- changes the job dependency tracking to track sets of abstact
parent jobs rather than individual parent jobs.
As a note, the purpose of the ValidationBarrier is that it allows us
to launch gossip validation jobs in goroutines while still ensuring
that the validation order of these goroutines is adhered to when it
comes to validating ChannelAnnouncement _before_ ChannelUpdate and
_before_ NodeAnnouncement.
This omits calls to InitJobDependencies, SignalDependants, and
WaitForDependants. These changes have been made here because
the router / builder code does not actually need job dependency
management. Calls to the builder code (i.e. AddNode, AddEdge,
UpdateEdge) are all blocking in the gossiper. This, combined
with the fact that child jobs are run after parent jobs in the
gossiper, means that the calls to the router will happen in the
proper dependency order.
Find and replace all nolint instances refering to the `lll` linter and
replace with `ll` which is the name of our custom version of the `lll`
linter which can be used to ignore log lines during linting.
The next commit will do the configuration of the custom linter and
disable the default one.
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.
