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.
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.
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.
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.
In this commit, we update the `CommitSpendNoDelay` method to be aware of
the alternate spending mechanism for commitments that don't have a tweak
for the remote party's non-delay output. We also add a new witness type
so callers can convey their expected signing path.
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.
In this commit, we extend the WitnessGenerator type to now return an
InputScript. This allows it to be more encompassing, as now callers can
expect a sigScript to be populated if the input being swept requires a
sigScript field.
Along the way, we've also renamed input.BuildWitness to
input.CraftInputScript. We also take a step towards allowing the
sweeper to sweep transactions for n2pwkh outputs. We do so by modifying
the BuiltWitness method to instead return an InputScript. Additionally,
when populating inputs if a sigScript is present, it will now be
populated.
