The class TxBatcher handles the creation, broadcast and replacement
of replaceable transactions. Callers (LNWatcher, SwapManager) use
methods add_payment_output and add_sweep_info. Transactions
created by TxBatcher may combine sweeps and outgoing payments.
Transactions created by TxBatcher will have their fee bumped
automatically (this was only the case for sweeps before).
TxBatcher manages several TxBatches. TxBatches are created
dynamically when needed.
The GUI does not touch txbatcher transactions:
- wallet.get_candidates_for_batching excludes txbatcher
transactions
- RBF dialogs do not work with txbatcher transactions
wallet:
- instead of reading config variables, make_unsigned_transaction
takes new parameters: base_tx, send_change_to_lighting
tests:
- unit tests in test_txbatcher.py (replaces test_sswaps.py)
- force all regtests to use MPP, so that we sweep transactions
with several HTLCs. This forces the payment manager to aggregate
first-stage HTLC tx inputs. second-stage are not batched for now.
- Wallet.make_unsigned_transaction takes a FeePolicy parameter
- fee sliders act on a FeePolicy instead of config
- different fee policies may be used for different purposes
- do not detect dust outputs in lnsweep, delegate that to lnwatcher
- reduce number of methods
- use nametuples instead of dicts
- only two types: OnchainHistoryItem and LightningHistoryItem
- channel open/closes are groups
- move capital gains into separate RPC
Clicking "max" btn for a reverse swap was setting the text field to a too high value.
```
>>> wallet.lnworker.num_sats_can_send()
Decimal('1242647.947')
>>> util.format_satoshis_plain(Decimal('1242647.947'))
'0.01242648'
```
- Separation between SwapManager and its transport:
Legacy transpport uses http, Nostr uses websockets
- The transport uses a context to open/close connections.
This context is not async, because it needs to be called
from the GUI
- Swapserver fees values are initialized to None instead
of 0, so that any attempt to use them before the swap
manager is initialized will raise an exception.
- Remove swapserver fees disk caching (swap_pairs file)
- Regtests use http transport
- Android uses http transport (until QML is ready)
Instead of some functions operating with hex strings,
and others using bytes, this consolidates most things to use bytes.
This mainly focuses on bitcoin.py and transaction.py,
and then adapts the API usages in other files.
Notably,
- scripts,
- pubkeys,
- signatures
should be bytes in almost all places now.
This gives more time for the client to come back online.
see https://github.com/spesmilo/electrum/issues/8940
- re note on submarine_swaps.py#L53:
lnpeer.Peer.maybe_fulfill_htlc only checks against MIN_FINAL_CLTV_DELTA_ACCEPTED(=144),
so this increased cltv_delta is not enforced when receiving the htlc on ln.
It is put in the invoice, so the sender is supposed to honour it ofc.
It would be nice to enforce it (make the check in maybe_fulfill_htlc dependent on
what was in the invoice).
- all forwarding types use the same flow
- forwarding callback returns a htlc_key or None
- forwarding info is persisted in lnworker:
- ongoing_forwardings
- downstream to upstream htlc_key
- htlc_key -> error_bytes
where the user has the preimage.
The CLTV requirements between old and new flow are imcompatible.
With the current locktime value, the server was vulnerable to an
attack where the client does not settle the lightning payment
and claims a refund. In order to support both old and new flows,
one would need to use different locktimes.
