In this commit, we implement the full RouterServer as specified by the
newly added sub-service as defined in router.proto. This new sub-server
has its own macaroon state (but overlapping permissions which can be
combined with the current admin.macaroon), and gives users a simplified
interface for a gRPC service that is able to simply send payment. Much
of the error reporting atm, is a place holder, and a follow up commit
will put up the infrastructure for a proper set of errors.
This commit makes use of the batched AddWitness
method of the WitnessCache, in order to avoid
performing one write for each accepted preimage.
Additionally, this fixes an existing hole in the
consistency guarantees since the batched writes
are now guaranteed to take place before accepting
the next CommitSig. Previously, these writes were
processed in an unsynchronized go routine that
could be delayed arbitrarily long before being
executed.
With this change, the async_payments_benchmarks
actually shows a slight improvement in
performance, presumably because we no longer do
an individual write per preimage, even though
the execution is now explicitly in the critical
path. There is likely also a marginal performance
improvement from the reduction in goroutine
overhead.
In this commit, we modify the WitnessCache's
AddPreimage method to accept a variadic number
of preimages. This enables callers to batch
preimage writes in performance critical areas
of the codebase, e.g. the htlcswitch.
Additionally, we lift the computation of the
witnesses' keys outside of the db transaction.
This saves us from having to do hashing inside
and blocking other callers, and limits extraneous
blocking at the call site.
In this commit, we update lnd to build against the latest version of
neutrino. This new version fixes a bug left behind as a result of the
btcd filter bug fix. When we were comparing filters in order to ban
invalid peers, we used the old OP_RETURN filtering rather than the new
one. As a result, we might've rejected a valid filter/block as we were
applying the old (incorrect) rules.
In this commit, we also allow channel updates for our channels to be
sent reliably to our channel counterparty. This is especially crucial
for private channels, since they're not announced, in order to ensure
each party can receive funds from the other side.
In this commit, we implement a new subsystem for the gossiper that
uses some of the existing logic for resending channel announcement
signatures and implements it in a way to make it message-agnostic,
meaning that any type of message can be resent. Along the way we also
modify the way this works to prevent multiple goroutines per peer _and_
message.
A peerHandler will be spawned for each peer for which we attempt to send
a message reliably to. This handler is responsible for managing requests
to reliably send messages to a peer while also taking the peer's
connection lifecycle into account by requesting notifications for when
the peer connects/disconnects. A peer connection notification is first
requested to determine when we should attempt to send any pending
messages. After the messages are sent, a peer disconnection notification
is requested to ensure we don't continue to request connection
notifications while the peer remains connected. Once there are no more
pending messages left to be sent for a given peer, the peerHandler can
be torn down.
