In c70bd1f, we implemented tracking HTLCs by adding path information
for pending HTLCs to `InvoicePayer`’s `payment_cache` when receiving
specific events.
Since we can now track inflight HTLCs entirely within ChannelManager,
there is no longer a need for this to exist.
We introduce a new sealed trait BaseEventHandler that has a blanket
implementation for any T. Since the trait cannot be implemented outside
of the crate, this allow us to expose specific implementations of
InvoicePayer that allow for synchronous and asynchronous event handling.
When a user attempts to send a payment but it fails due to
idempotency key violation, they need to know that this was the
reason as they need to handle the error programmatically
differently from other errors.
Here we simply add a new `PaymentSendFailure` enum variant for
`DuplicatePayment` to allow for that.
It was pointed out that its quite confusing that
`AllFailedRetrySafe` does not allow you to call `retry_payment`,
though the documentation on it does specify this. Instead, we
simply rename it to `AllFailedResendSafe` to indicate that the
action that is safe to take is *resending*, not *retrying*.
This is part of moving the Router trait into ChannelManager, which will help
allow ChannelManager to fetch routes on-the-fly as part of supporting
trampoline payments.
In order to allow users to pass a custom idempotency key to the
`send*` methods in `InvoicePayer`, we have to pipe the `PaymentId`
through to the `Payer` methods, which we do here.
By default, existing `InvoicePayer` methods use the `PaymentHash`
as the `PaymentId`, however we also add duplicate `send*_with_id`
methods which allow users to pass a custom `PaymentId`.
Finally, appropriate documentation updates are made to clarify
idempotency guarantees.
In c986e52ce8, an `MppId` was added
to `HTLCSource` objects as a way of correlating HTLCs which belong
to the same payment when the `ChannelManager` sees an HTLC
succeed/fail. This allows it to have awareness of the state of all
HTLCs in a payment when it generates the ultimate user-facing
payment success/failure events. This was used in the same PR to
avoid generating duplicative success/failure events for a single
payment.
Because the field was only used as an internal token to correlate
HTLCs, and retries were not supported, it was generated randomly by
calling the `KeysInterface`'s 32-byte random-fetching function.
This also provided a backwards-compatibility story as the existing
HTLC randomization key was re-used for older clients.
In 28eea12bbe `MppId` was renamed to
the current `PaymentId` which was then used expose the
`retry_payment` interface, allowing users to send new HTLCs which
are considered a part of an existing payment.
At no point has the payment-sending API seriously considered
idempotency, a major drawback which leaves the API unsafe in most
deployments. Luckily, there is a simple solution - because the
`PaymentId` must be unique, and because payment information for a
given payment is held for several blocks after a payment
completes/fails, it represents an obvious idempotency token.
Here we simply require the user provide the `PaymentId` directly in
`send_payment`, allowing them to use whatever token they may
already have for a payment's idempotency token.
Mobile clients often take a second or two before they reconnect to
their peers as its not always clear immediately that connections
have been killed (especially on iOS). This can cause us to
spuriously fail to include route hints in our invoices if we're on
mobile.
The fix is simple, if we're selecting channels to include in route
hints and we're not not connected to the peer for any of our
channels, we should simply include the hints for all channels, even
though we're disconencted.
Fixes#1768.
We had a user who was confused why an invoice failed to round-trip
(i.e. was not `PartialEq` with itself after write/read) when a
subsecond creation time was used (e.g. via the `from_system_time`
constructor).
This commit should address this confusion by dropping subsecond
parts in easily-accessible constructors when creating BOLT 11
invoices.
Fixes#1759.
`hashbrown` depends on `ahash` which depends on `once_cell`. Sadly,
in https://github.com/matklad/once_cell/issues/201 the `once_cell`
maintainer decided they didn't want to do the work of having an
MSRV policy for `once_cell`, making `ahash`, and thus `hashbrown`
require the latest compiler. I've reached out to `ahash` to suggest
they drop the dependency (as they could trivially work around not
having it), but until then we simply downgrade `hashbrown`.
`rust-bitcoin` also requires an older `hashbrown` so we're actually
reducing our total `no-std` code here anyway.
In c353c3ed7c an accessor method was
added which returns an `Option<&u64>`. While this allows Rust to
return an 8-byte object, returning a reference to something
pointer-sized is a somewhat strange API.
Instead, we opt for a straight `Option<u64>`, which is sadly
somewhat larger on the stack, but is simpler and already supported
in the bindings generation.
In c353c3ed7c, new scorer-updating
methods were added to the `Router` object, however they were
passed as a `Vec` of references. We use the list-of-references
pattern to make bindings simpler (by not requiring allocations per
entry), however there's no reason prefer to passing a `Vec` over
a slice, given the `Vec` doesn't hold ownership of the objects
anyway.
We do this to enable users to create routers that do not need a scorer.
This can be useful if they are running a node the delegates pathfinding.
* Move `Score` type parameterization from `InvoicePayer` and `Router` to
`DefaultRouter`
* Adds a new field, `scorer`, to `DefaultRouter`
* Move `AccountsForInFlightHtlcs` to `DefaultRouter`, which we
will use to wrap the new `scorer` field, so scoring only happens in
`DefaultRouter` explicitly.
* Add scoring related functions to `Router` trait that we used to call
directly from `InvoicePayer`.
* Instead of parameterizing `scorer` in `find_route`, we replace it with
inflight_map so `InvoicePayer` can pass on information about inflight
HTLCs to the router.
* Introduced a new tuple struct, InFlightHtlcs, that wraps functionality
for querying used liquidity.
As we move towards specify supported/required feature bits in the
module(s) where they are supported, the global `known` feature set
constructors no longer make sense.
Here we stop relying on the `known` method in the
`lightning-invoice` crate.
Now that `{Signed,}RawInvoice` implement the std `Hash` trait,
having a method called `hash` is ambiguous.
Instead, we rename the `hash` methods `signed_hash` to make it
clear that the hash is the one used for the purpose of signing the
invoice.
The `rejected_by_dest` field of the `PaymentPathFailed` event has
always been a bit of a misnomer, as its really more about retry
than where a payment failed. Now is as good a time as any to
rename it.
Made sure that every hop has a unique receipient. When we simulate
calling `channel_penalty_msat` in `TestRouter`’s find route, use
actual previous node ids instead of just using the payer’s.
Added two methods, `process_path_inflight_htlcs` and
`remove_path_inflight_htlcs`, that updates that `payment_cache` map with
path information that may have failed, succeeded, or have been given up
on.
Introduced `AccountForInflightHtlcs`, which will wrap our user-provided
scorer. We move the `S:Score` type parameterization from the `Router` to
`find_route`, so we can use our newly introduced
`AccountForInflightHtlcs`.
`AccountForInflightHtlcs` keeps track of a map of inflight HTLCs by
their short channel id, direction, and give us the value that is being
used up.
This map will in turn be populated prior to calling `find_route`, where
we’ll use `create_inflight_map`, to generate a current map of all
inflight HTLCs based on what was stored in `payment_cache`.
