Previously the invoice registry wasn't aware of replayed htlcs. This was
dealt with by keeping the invoice accept/settle logic idempotent, so
that a replay wouldn't have an effect.
This mechanism has two limitations:
1. No accurate tracking of the total amount paid to an invoice. The total
amount couldn't just be increased with every htlc received, because it
could be a replay which would lead to counting the htlc amount multiple
times. Therefore the total amount was set to the amount of the first
htlc that was received, even though there may have been multiple htlcs
paying to the invoice.
2. Impossible to check htlc expiry consistently for hodl invoices. When
an htlc is new, its expiry needs to be checked against the invoice cltv
delta. But for a replay, that check must be skipped. The htlc was
accepted in time, the invoice was moved to the accepted state and a
replay some blocks later shouldn't lead to that htlc being cancelled.
Because the invoice registry couldn't recognize replays, it stopped
checking htlc expiry heights when the invoice reached the accepted
state. This prevents hold htlcs from being cancelled after a restart.
But unfortunately this also caused additional htlcs to be accepted on an
already accepted invoice without their expiry being checked.
In this commit, the invoice registry starts to persistently track htlcs
so that replays can be recognized. For replays, an htlc resolution
action is returned early. This fixes both limitations mentioned above.
As the logic around invoice mutations gets more complex, the friction
caused by having this logic split between invoice registry and channeldb
becomes more apparent. This commit brings a clearer separation of
concerns by centralizing the accept/settle logic in the invoice
registry.
The original AcceptOrSettle method is renamed to UpdateInvoice because
the update to perform is controlled by the callback.
This commit adds a set of htlcs to the Invoice struct and
serializes/deserializes this set to/from disk. It is a preparation for
accurate invoice accounting across restarts of lnd.
A migration is added for the invoice htlcs.
In addition to these changes, separate final cltv delta and expiry
invoice fields are created and populated. Previously it was required
to decode this from the stored payment request. The reason to create
a combined commit is to prevent multiple migrations.
This commit adds an index bucket, disabledEdgePolicyBucket, for those
ChannelEdgePolicy with disabled bit on.
The main purpose is to be able to iterate over these fast when prune is
needed without the need for iterating the whole graph.
The entry points for accessing this index are:
1. When updating ChannelEdgePolicy - insert an entry.
2. When deleting ChannelEdge - delete the associated entries.
3. When querying for disabled channels - implemented DisabledChannelIDs
function
This commit modifies the nodeWithDist struct to use a route.Vertex
instead of a *channeldb.LightningNode. This change, coupled with
the new ForEachNodeChannel function, allows the findPath Djikstra's
algorithm to cut down on database lookups since we no longer need
to call the FetchOtherNode function.
This commit specifies two bbolt options when opening the underlying
channel and watchtower databases so that there is reduced heap
pressure in case the bbolt database has a lot of free pages in the
B+ tree.
Previously the migration would fail if the source node was not set in
the database. Since we know that the source node must have been set
before making any payments, we check whether there actually are any
payments to migrate, and return early if not.
This commit makes the router use the ControlTower to drive the payment
life cycle state machine, to keep track of active payments across
restarts. This lets the router resume payments on startup, such that
their final results can be handled and stored when ready.
This commit gives a new responsibility to the control tower, letting it
populate the payment bucket structure as the payment goes through
its different stages.
The payment will transition states Grounded->InFlight->Success/Failed,
where the CreationInfo/AttemptInfo/Preimage must be set accordingly.
This will be the main driver for the router state machine.
migrateOutgoingPayments moves the OutgoingPayments into a new bucket format
where they all reside in a top-level bucket indexed by the payment hash. In
this sub-bucket we store information relevant to this payment, such as the
payment status.
To avoid that the router resend payments that have the status InFlight (we
cannot resume these payments for pre-migration payments) we delete those
statuses, so only Completed payments remain in the new bucket structure.
This commit changes the format used to store payments within the
DB. Previously this was serialized as one continuous struct
OutgoingPayment, which also contained an Invoice struct we where only
using a few fields of. We now split it up into two simpler sub-structs
CreationInfo, AttemptInfo and PaymentPreimage.
We also want to associate the payments more closely with payment
statuses, so we move to this hierarchy:
There's one top-level bucket "sentPaymentsBucket" which contains a set
of sub-buckets indexed by a payment's payment hash. Each such sub-bucket
contains several fields:
paymentStatusKey -> the payment's status
paymentCreationInfoKey -> the payment's CreationInfo.
paymentAttemptInfoKey -> the payment's AttemptInfo.
paymentSettleInfoKey -> the payment's preimage (or zeroes for
non-settled payments)
The CreationInfo is information that is static during the whole payment
lifcycle. The attempt info is set each time a new payment attempt
(route+paymentID) is sent on the network. The preimage is information
only known when a payment succeeds. It therefore makes sense to split
them.
We keep legacy serialization code for migration puproses.
This commit adds persisted status bit-field to ClientSessions, that can
be used to modify behavior of their handling in the client. Currently,
only a default CSessionActive status is defined. However, the intention
is that this could later be used to signal that a session is abandoned
without needing to perform a db migration to add the field. As we move
forward with testing, this will likely be useful if a session gets
borked and we need a simple method of the client to temporarily ignore
certain sessions.
The field may be useful in signaling other types of status changes,
though this was the primary motivation that warranted the addition.
