This commit exports and renames the following variable names:
- `PendingInput` is now `PendingInputResponse` as it's responding to a
request.
- `pendingInput` is now renamed and exported as `SweeperInput`.
- `pendingInputs` is now renamed and exported as `InputsMap`.
This commit is first made from running:
```
gofmt -d -w -r 'PendingInput -> PendingInputResponse' .
gofmt -d -w -r 'pendingInput -> SweeperInput' .
gofmt -d -w -r 'pendingInputs -> InputsMap' .
```
And followed by some docs and variable names fixes.
There's no need use the prefix `pending` as the inputs in the sweeper
can only be pending, so it's renamed, also to avoid the confusion with
the type `pendingInputs`.
This commit adds a private type `mSatPerKWeight` that expresses a given
fee rate in millisatoshi per kw. This is needed to increase the
precision of the fee function. When sweeping anchor inputs, if using a
deadline delta of over 1000, it's likely the delta will be 0 sat/kw due
to precision.
This commit finishes the implementation of `TxPublisher` by adding the
monitor process. Whenever a new block arrives, the publisher will check
all its monitored records and attempt fee bumping them if necessary.
This commit adds `TxPublisher` which implements `Bumper` interface. This
is part one of the implementation that focuses on implementing the
`Broadcast` method which guarantees a tx can be published with
RBF-compliant. It does so by leveraging the `testmempoolaccept` API,
keep increasing the fee rate until an RBF-compliant tx is made and
broadcasts it.
This tx will then be monitored by the `TxPublisher` and in the following
commit, the monitoring process will be added.
This commit adds the method `MaxFeeRateAllowed` to calculate the max fee
rate. The caller may specify a large MaxFeeRate value, which cannot be
cover by the budget. In that case, we default to use the max feerate
calculated using `budget/weight`.
This commit adds a new interface, `FeeFunction`, to deal with
calculating fee rates. In addition, a simple linear function is
implemented, hence `LinearFeeFunction`, which will be used to calculate
fee rates when bumping fees. Check #4215 for other type of fee functions
that can be implemented.
As shown in the following commit, fee rate calculation will now be
handled by the fee bumper, hence there's no need to expose this on
`InputSet` interface.
This commit adds a new interface, `Bumper`, to handle RBF for a given
input set. It's responsible for creating the sweeping tx using the input
set, and monitors its confirmation status to decide whether a RBF should
be attempted or not.
We leave implementation details to future commits, and focus on mounting
this `Bumper` interface to our sweeper in this commit.
This commit adds `BudgetAggregator` as a new implementation of
`UtxoAggregator`. This aggregator will group inputs by their deadline
heights and create input sets that can be used directly by the fee
bumper for fee calculations.
This commit adds `BudgetInputSet` which implements `InputSet`. It
handles the pending inputs based on the supplied budgets and will be
used in the following commit.
This commit changes `markInputsPendingPublish` to take `InputSet` only.
This is needed for the following commits as we won't be able to know the
tx being created beforehand, yet we still want to make sure these inputs
won't be grouped to another input set as it complicates our RBF process.
This commit changes how `WithCoinSelectLock` is used - previously the
lock is held when creating the input sets, now it's only be held after
the input sets have been created and explicitly signal they need wallet
inputs.
This commit makes the `ClusterInputs` directly returning the `InputSet`
so the sweeper doesn't know about the existence of `Cluster` interface.
This way we can have a deeper interface as the sweeper only needs to
interact with `Aggregator` only to get the final input sets, leaving the
implementation details being managed by `SimpleAggregator` and future
aggregators.
Previously the fee rate is tracked at cluster level, which may not be
accurate as each cluster is then divided into input sets. And these sets
are what's actually included in the final sweeping tx. To properly
reflect the final fee rate used in the sweeping tx, `InputSet` is added
so more customized clustering logic can be implemented in the future.
For intance, atm it's clustered by fee rates, while we may also cluster
by deadlines, urgencies, etc.
This commit adds a new interface `Cluster` to manage cluster-level
inputs grouping. This new interface replaces the `inputCluster` and will
be futher refactored so the sweeper can use a much smaller coin
selection lock.
This commit changes the source that drives the state changes in the
sweeper. Previously we used a ticker with default interval of 30s to
trigger sweepings periodically. The assumption is, within this 30s we'd
batch multiple inputs into one transaction to maximize profits. However,
the efficacy of this batch is questionable.
At a high level, we can put our inputs into two categories - one that's
forced, and one that's not. For forced inputs, we should sweep them
immediately as the force flag indicates they are very urgent, eg,
CPFPing the force closing tx. For non-forced inputs, such as anchors
or HTLCs with CLTV that's far away, we can wait to sweep them till a new
block comes in and triggers the sweeping process.
Eventually, all inputs will be deadline-aware, and the sweeper will
consult our fee bumper about the most economical fee rate to be used for
a given deadline. Since the deadlines here are blockstamp, it's also
easier to manage them if the sweeper is also using blockstamp instead of
timestamp.
sweeper
This commit implements a new method, `LookupInputMempoolSpend` to do
lookups in the mempool. This method is useful in the case when we only
want to know whether an input is already been spent in the mempool by
the time we call.
This commit removes the logic where we remove an input when it's been
published more than 10 times. This is needed as in our future fee
bumper, we might start with a low fee and rebroadcast the same input for
hundred of blocks.
This commit changes how a new input sweep request is handled - now we
will query the mempool and see if it's already been spent. If so, we'll
update its state as we may need to RBF this input.
