Implement logic to claim a reverse swap funding output to any given
address. This allows to do onchain payments to external recipients
through a submarine swap.
1. Do not remove local transaction in find_base_tx.
This logic was intended to cleanup claim transactions that are
never broadcast (for example, if the counterparty gets a refund)
(see 1bf1de36cb)
However, this code is too unspecific and may result in fund loss,
because the transaction being removed may contain outgoing payments.
For example, if the electrum server is not responsive, the tx will
be seen as local and deleted. In that case, another payment will
be attempted, thus paying twice.
2. Do not remove tx after try_broadcasting returns False.
The server might be lying to us. We can only remove the local tx
if there is a base_tx, because the next tx we create will try to
spend the same output.
```
$ export ELECTRUM_LINTERS=E9,E101,E129,E273,E274,E703,E71,E722,F5,F6,F7,F8,W191,W29,B
$ export ELECTRUM_LINTERS_IGNORE=B007,B009,B010,B019,B036,F541,F841
$ flake8 . --count --select="$ELECTRUM_LINTERS" --ignore="$ELECTRUM_LINTERS_IGNORE" --show-source --statistics --exclude "*_pb2.py,electrum/_vendor/"
./electrum/commands.py:98:1: F811 redefinition of unused 'format_satoshis' from line 48
def format_satoshis(x):
^
./electrum/commands.py:437:9: F811 redefinition of unused 'Mnemonic' from line 62
from .mnemonic import Mnemonic
^
./electrum/gui/qt/wizard/wallet.py:37:5: F811 redefinition of unused 'Daemon' from line 14
from electrum.daemon import Daemon
^
./electrum/lntransport.py:14:1: F811 redefinition of unused 'Optional' from line 12
from typing import NamedTuple, List, Tuple, Mapping, Optional, TYPE_CHECKING, Union, Dict, Set, Sequence
^
./electrum/lntransport.py:14:1: F811 redefinition of unused 'TYPE_CHECKING' from line 12
from typing import NamedTuple, List, Tuple, Mapping, Optional, TYPE_CHECKING, Union, Dict, Set, Sequence
^
./electrum/plugin.py:966:13: F811 redefinition of unused 'hid' from line 593
import hid
^
./electrum/plugin.py:1040:13: F811 redefinition of unused 'hid' from line 593
import hid
^
./electrum/util.py:44:1: F811 redefinition of unused 'json' from line 26
import json
^
./electrum/util.py:46:1: F811 redefinition of unused 'NamedTuple' from line 29
from typing import NamedTuple, Optional
^
./electrum/util.py:46:1: F811 redefinition of unused 'Optional' from line 29
from typing import NamedTuple, Optional
^
./electrum/util.py:1456:56: F811 redefinition of unused 'traceback' from line 34
async def __aexit__(self, exc_type, exc_value, traceback):
^
./electrum/wallet_db.py:536:9: F811 redefinition of unused 'LOCAL' from line 46
LOCAL = 1
^
./electrum/wallet_db.py:537:9: F811 redefinition of unused 'REMOTE' from line 46
REMOTE = -1
^
./tests/test_bitcoin.py:28:1: F811 redefinition of unused 'bitcoin' from line 9
from electrum import crypto, constants, bitcoin
^
./tests/test_txbatcher.py:11:1: F811 redefinition of unused 'Transaction' from line 7
from electrum.transaction import Transaction, PartialTxInput, PartialTxOutput, TxOutpoint
^
./tests/test_wallet_vertical.py:20:1: F811 redefinition of unused 'Transaction' from line 10
from electrum.transaction import Transaction, PartialTxOutput, tx_from_any, Sighash
^
16 F811 redefinition of unused 'format_satoshis' from line 48
16
```
With `txbatcher.SLEEP_INTERVAL = 0.01`, on my laptop, the batcher called try_broadcasting() even before next_tx() effectively awaited _tx_event.
This resulted in the test failing due to timeout.
Basically, if the txbatcher.SLEEP_INTERVAL was too low, the 2-4 event loop iterations needed to await _tx_event.wait() took too long.
(note that the exact number of event loop iterations needed depends on the python version and the OS)
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.
