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.
This commit fixes an issue that would arise if inputs without required
TxOuts would be swept together with inputs with required TxOuts. In this
case we would add the required ones first to the transaction, but did
not change the order we signed the inputs, resulting in signing the
wrong input index.
Now that inputs might have accompanied outputs to be added to the sweep
tx, we add them to the sweep transaction first, and account for it when
calculating the change amount.
If inputs require outputs to be added at the same time, this will
change the weight and amount calculations, so we must account for that.
We wait to get the weight estimator for the sweep tx until needed,
such that we can easily choose whether to include a change output or not
in the estimate. This is needed for the case where the second level
transactions can pay for their own fee, so no change output is needed.
Similarly as with kvdb.View this commits adds a reset closure to the
kvdb.Update call in order to be able to reset external state if the
underlying db backend needs to retry the transaction.
This commit adds a reset() closure to the kvdb.View function which will
be called before each retry (including the first) of the view
transaction. The reset() closure can be used to reset external state
(eg slices or maps) where the view closure puts intermediate results.
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.
Preparation for a cpfp-aware weight estimator. For cpfp, a regular
weight estimator isn't sufficient, because it needs to take into account
the weight of the parent transaction(s) as well.
The sweeper call UpdateParams does not update the exclusive group
property of a pending sweep. This led to anchor outputs being swept
after confirmation with an exclusive group restriction, which is not
necessary.
This commit changes the anchor resolver to not use UpdateParams anymore,
but instead always re-offer the anchor input to the sweeper. The sweeper
is modified so that a re-offering also updates the sweep parameters.
The add function tries to add an input to the current set. It therefore
calculates what the new set would look like before actually adding. This
commit isolates the state of the tentative set so that there is less
opportunity for bugs to creep in.
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.
Add label parameter to PublishTransaction in WalletController
interface. A labels package is added to store generic labels that are
used for the different types of transactions that are published by lnd.
To keep commit size down, the two endpoints that require a label
parameter be passed down have a todo added, which will be removed in
subsequent commits.
This commit introduces a new test case that asserts all of the witness
size constants currently in the codebase. We also reintroduce the
AcceptedHtlcSuccessWitnessSize and OfferedHtlcTimeoutWitnessSize
constants that were recently removed for the sake of completeness.
In asserting the witnes sizes, there were three uncovered discrepancies:
* OfferedHtlcSuccessWitnessSize overestimated by about 30% because it
included an extra signature in the calculation.
* ToLocalPenaltyWitnessSize was underestimated by one byte, because it
was missing the length byte for the OP_TRUE. This has implications
the watchtower protocol since the client and server are assumed to
share the same weight estimates used for signing. This commit keeps
the current behavior, with the intention of rolling out negotiation
for which weight estimate to use for a given session.
* AcceptedHtlcScriptSize was underestimated by one byte because it was
missing a length byte for the value 32 pushed on the stack when
asserting the preimage's length. This affects all AcceptedHtlc*
witness sizes.
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.
We also increase the witness size for these types to account for the 3
extra bytes. The size won't be correct in all cases, but it is just an
upper bound in any case.
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.
Previously only the fee rate used for the last sweep (the sweep bucket
average) was reported. This commit adds the request fee preference to
the report, which is used to select a bucket and the sweep tx fee rate.
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.
A refactoring that introduces no functional changes. This prepares for
the addition of wallet utxos to push the sweep tx above the dust limit.
It also enabled access to input-specific sweep parameters during tx
generation. This will be used in later commits to control the sweep
process.
