Previously it wasn't possible to store a preimage in the invoice
database and signal that a payment should not be settled right away. The
only way to hold a payment was to insert the magic UnknownPreimage value
in the invoice database. This commit introduces a distinct flag to
signal that an invoice is a hold invoice and thereby allows the preimage
to be present in the database already.
Preparation for (key send) hodl invoices for which we already know the
preimage.
This commit moves the db calls for retrieving add and settle backlogs
outide of the main event loop. All other db operations are performed
outside of the event loop and synchronized via the invoice registry's
mutex, which also synchronizes the order in which events submitted to be
processed.
This resolves various concurrency issues where notifications can be
missed of inconsistent reads against the databse. This is especially
important in this case because we are actually making two separate
database calls.
This commit adds LinkErrors with failure details to htlcs which fail on
our incoming link. This change is made with the intention of notifying
detailed htlc failure reasons in sendHTLCError. The FailureDetail
interface is implemented on FailureResolutionResults so that they can
directly be used to enrich LinkErrors. sendHtlcError is updated to
take a LinkError in preparation for the addition of a htlcnotifier
which will notify the detail of the error.
This commit splits the resolution result enum into results divided
by outcome (settled, failed or accepted). This allows us to more
strictly control which resolution results can be used with which
HtlcResolution structs, to prevent the combination of a settle
resolution result with a failure resolution result, for example.
This commit repalces the htlcResolution struct with an interface.
This interface is implemeted by failure, settle and accept resolution
structs. Only settles and fails are exported because the existing
code that handles htlc resolutions uses a nil resolution to indicate
that a htlc was accepted. The accept resolution is used internally
to report on the resolution result of the accepted htlc, but a nil
resolution is surfaced. Further refactoring of all the functions
that call NotifyExitHopHtlc to handle a htlc accept case (rather than
having a nil check) is required.
This commit intends to fix slow first startup time when there are many
invoices that need to be canceled. The slowdown is caused by a combination
of adding invoices to the expiry watcher one-by-one and slow
cancellation. Due to slow cancellation and the unbuffered channel which
we use to pass invoices to the expiry watcher blocks the registry.
With this fix we'll instead batch add invoices to the expiry watcher and
thereby won't block the registry startup.
This commit adds handling code for the key send custom record. If this
record is present and its hash matches the payment hash, invoice
registry will insert a new invoice into the database "just in time". The
subsequent settle flow is unchanged. The newly inserted invoice is
picked up and settled. Notifications will be broadcast as usual.
This commit moves handling of invoice not found
errors into NotifyExitHopHtlc and exposes a
resolution result to the calling functions. The
intention of this change is to make calling
functions as naive of the invoice registry's
mechanics as possible.
When NotifyExitHopHtlc is called and an invoice
is not found, calling functions can take action
based on the HtlcResolution's InvoiceNotFound
outcome rather than having to add a special error
check on every call to handle the error.
This commit adds the resolution result obtained
while updating an invoice in the registry to
htlcResolution. The field can be used by calling
functions to determine the outcome of the
update and act appropriately.
This commit adds a constructor for HtlcResolution creation
to enforce provision of all relevant values when an
event is created. A custom construstor which also takes
a preimage is added for settle events.
This commit renames HodlEvent to HtlcResolution
to better reflect the fact that the struct is
only used for htlc settles and cancels, and that
it is not specifically used for hodl invoices.
This commit exports UpdateResult so that
calling functions can interpret the outcome
of an invoice update. This is useful for
determining the wire failure required
(fail invalid details or mpp_timeout once
implemented) and for notifying specific
htlc failure details. The enum is renamed
to ResolutionResult.
This commit adds InvoiceExpryWatcher which is a separate class that
receives new invoices (and existing ones upon restart) from InvoiceRegistry
and actively watches their expiry. When an invoice is expired
InvoiceExpiryWatcher will call into InvoiceRegistry to cancel the
invoice and by that notify all subscribers about the state change.
This commit adds Clock and DefaultClock and moves the private
invoices.testClock under the clock package while adding basic
unit tests for it.
Clock is an interface currently encapsulating Now() and TickAfter().
It can be added as an external dependency to any class. This way
tests can stub out time.Now() or time.After().
The DefaultClock class simply returns the real time.Now() and
time.After().
Previously the cancel and add actions were combined in a single map.
Nil values implictly signaled cancel actions. This wasn't very obvious.
Furthermore this split prepares for processing the adds and cancels
separately, which is more efficient if there are already two maps.
This commit moves the update code into its own function as a preparation
for extending the logic further for mpp.
In order to make this change cleanly, structured result codes are
introduced. This also prepares for a future htlc notifier rpc hook that
reports htlc settle decisions to external applications.
Furthermore the awkward use of errNoUpdate as a way to signal no update
is removed.
This commit adds a test context for invoice registry and additionally
passed in a payload object to NotifyExitHopHtlc. This makes the test
match the reality better where a payload is always provided.
This commit restructures an invoice's ContractTerms to better encompass
the restrictions placed on settling. For instance, the final ctlv delta
and invoice expiry are moved from the main invoice body (where
additional metadata is stored). Additionally, it moves the State field
outside of the terms since it is rather metadata about the invoice
instead of any terms offered to the sender in the payment request.
