We risked deadlocking on shutdown if a client (in our case a contract
resolver) attempted to schedule a sweep of an input after the
ChainNotifier had been shut down. This would cause the `collector`
goroutine to exit, and not handle incoming requests, causing a deadlock
(since the ChainArbitrator is being stopped before the Sweeper in the
server).
To fix this we could change the order these subsystems are stopped, but
this doesn't ensure there aren't other clients that could end up in the
same deadlock scenario. So instead we keep handling the incoming
requests even after the collector has exited (immediatly returning an
error), until the sweeper is signalled to shutdown.
This add a test for inputs that gets re-ordered because the inputs with
required TxOuts must be added first.
We add a new step to the test that checks that all inputs were signed at
the correct tx input index.
This test would fail without the previous commit.
Extend the fee estimator to take into account parent transactions with
their weights and fees.
Do not try to cpfp parent transactions that have a higher fee rate than
the sweep tx fee rate.
This commit moves all localized instances of mock implementations of
the Signer interface to the lntest/mock package. This allows us to
remove a lot of code and have it housed under a single interface in
many cases.
Exclusive group is a static property that doesn't need to be updated.
Requiring the exclusive group to be passed into UpdateParams creates a
burden for the caller to make sure they supply the existing group.
This change will be beneficial for users that bump anchor sweeps that
have exclusive groups set.
Allows certain sweep inputs to be kept in separate transactions at all
times. This is a preparation for anchor outputs. Before the commitment
tx confirms, there are three potential anchors that can be cpfp'ed. We
want to cpfp them all, but if done in the same transaction, the
transaction would guaranteed to be invalid. Exponential backoff would
eventually get the txes published, but having exclusive groups makes the
process faster.
This commit allows sweeper to sweep inputs that on its own are not able
to form a sweep transaction that meets the dust limit.
This functionality is useful for sweeping small outputs. In the future,
this will be particularly important to sweep anchors. Anchors will
typically be spent with a relatively large fee to pay for the parent tx.
It will then be necessary to attach an additional wallet utxo.
In this commit, we create a new chainfee package, that houses all fee
related functionality used within the codebase. The creation of this new
package furthers our long-term goal of extracting functionality from the
bloated `lnwallet` package into new distinct packages. Additionally,
this new packages resolves a class of import cycle that could arise if a
new package that was imported by something in `lnwallet` wanted to use
the existing fee related functions in the prior `lnwallet` package.
Because the BestBlock method of ChainIO is not exposed through any
RPC we want to get rid of it so we can use the sweeper outside of
lnd too. Since the chain notifier now also delivers the current best
block we don't need the BestBlock method any more.
In this commit, we introduce the ability to bump the fee of an input
within the UtxoSweeper. Once its fee rate is bumped, a replacement
transaction (RBF) will be broadcast with the newer fee rate (assuming
the newer fee rate is high enough to be valid), replacing any
conflicting lower fee rate transactions.
Note that this currently doesn't validate the fee preference of the
bump. This responsibility is delegated to the caller, so care must be
taken to ensure the new fee preference is sufficient.
In this commit, we address another issue that arose with the
introduction of the fee rate buckets. We'll use an example to explain
the problem space:
Let's say we have inputs A, B, and C within the same fee rate bucket. If
A's fee rate is bumped to a higher bucket, then it's currently possible
for the lower fee rate bucket to be swept first, which would produce an
invalid RBF transaction since we're removing an input from the original
without providing a higher fee. By the time we get to the higher fee
rate bucket, we broadcast a valid RBF transaction _only_ sweeping input
A, which would evict the transaction sweeping inputs B and C from the
mempool.
To prevent this eviction, we can simply broadcast the higher fee rate
sweep transactions first, to ensure we have valid RBF transactions.
In this commit, we introduce support for arbitrary client fee
preferences when accepting input sweep requests. This is possible with
the addition of fee rate buckets. Fee rate buckets are buckets that
contain inputs with similar fee rates within a specific range, e.g.,
1-10 sat/vbyte, 11-20 sat/vbyte, etc. Having these buckets allows us to
batch and sweep inputs from different clients with similar fee rates
within a single transaction, allowing us to save on chain fees.
With this addition, we can now get rid of the UtxoSweeper's default fee
preference. As of this commit, any clients using the it to sweep inputs
specify the same fee preference to not change their behavior. Each of
these can be fine-tuned later on given their use cases.
This commit is a step to split the lnwallet package. It puts the Input
interface and implementations in a separate package along with all their
dependencies from lnwallet.
In this commit, we update the `getInputWitnessSizeUpperBound` and all
its callers to be aware of nested p2sh witness inputs. We do so by
adding another bool which is true if the output is a nested p2sh output.
If so, then in order to properly estimate the total weight, the caller
needs to factor in the non-witness data of the additional sigScript data
push.
