from copy import deepcopy from typing import Optional, Sequence, Tuple, List, Dict, TYPE_CHECKING from .lnutil import SENT, RECEIVED, LOCAL, REMOTE, HTLCOwner, UpdateAddHtlc, Direction, FeeUpdate from .util import bh2u, bfh if TYPE_CHECKING: from .json_db import StoredDict class HTLCManager: def __init__(self, log:'StoredDict', *, initial_feerate=None): if len(log) == 0: initial = { 'adds': {}, 'locked_in': {}, 'settles': {}, 'fails': {}, 'fee_updates': {}, # "side who initiated fee update" -> action -> list of FeeUpdates 'revack_pending': False, 'next_htlc_id': 0, 'ctn': -1, # oldest unrevoked ctx of sub } log[LOCAL] = deepcopy(initial) log[REMOTE] = deepcopy(initial) log['unacked_local_updates2'] = {} # maybe bootstrap fee_updates if initial_feerate was provided if initial_feerate is not None: assert type(initial_feerate) is int for sub in (LOCAL, REMOTE): if not log[sub]['fee_updates']: log[sub]['fee_updates'][0] = FeeUpdate(rate=initial_feerate, ctn_local=0, ctn_remote=0) self.log = log def ctn_latest(self, sub: HTLCOwner) -> int: """Return the ctn for the latest (newest that has a valid sig) ctx of sub""" return self.ctn_oldest_unrevoked(sub) + int(self.is_revack_pending(sub)) def ctn_oldest_unrevoked(self, sub: HTLCOwner) -> int: """Return the ctn for the oldest unrevoked ctx of sub""" return self.log[sub]['ctn'] def is_revack_pending(self, sub: HTLCOwner) -> bool: """Returns True iff sub was sent commitment_signed but they did not send revoke_and_ack yet (sub has multiple unrevoked ctxs) """ return self.log[sub]['revack_pending'] def _set_revack_pending(self, sub: HTLCOwner, pending: bool) -> None: self.log[sub]['revack_pending'] = pending def get_next_htlc_id(self, sub: HTLCOwner) -> int: return self.log[sub]['next_htlc_id'] ##### Actions on channel: def channel_open_finished(self): self.log[LOCAL]['ctn'] = 0 self.log[REMOTE]['ctn'] = 0 self._set_revack_pending(LOCAL, False) self._set_revack_pending(REMOTE, False) def send_htlc(self, htlc: UpdateAddHtlc) -> UpdateAddHtlc: htlc_id = htlc.htlc_id if htlc_id != self.get_next_htlc_id(LOCAL): raise Exception(f"unexpected local htlc_id. next should be " f"{self.get_next_htlc_id(LOCAL)} but got {htlc_id}") self.log[LOCAL]['adds'][htlc_id] = htlc self.log[LOCAL]['locked_in'][htlc_id] = {LOCAL: None, REMOTE: self.ctn_latest(REMOTE)+1} self.log[LOCAL]['next_htlc_id'] += 1 return htlc def recv_htlc(self, htlc: UpdateAddHtlc) -> None: htlc_id = htlc.htlc_id if htlc_id != self.get_next_htlc_id(REMOTE): raise Exception(f"unexpected remote htlc_id. next should be " f"{self.get_next_htlc_id(REMOTE)} but got {htlc_id}") self.log[REMOTE]['adds'][htlc_id] = htlc self.log[REMOTE]['locked_in'][htlc_id] = {LOCAL: self.ctn_latest(LOCAL)+1, REMOTE: None} self.log[REMOTE]['next_htlc_id'] += 1 def send_settle(self, htlc_id: int) -> None: self.log[REMOTE]['settles'][htlc_id] = {LOCAL: None, REMOTE: self.ctn_latest(REMOTE) + 1} def recv_settle(self, htlc_id: int) -> None: self.log[LOCAL]['settles'][htlc_id] = {LOCAL: self.ctn_latest(LOCAL) + 1, REMOTE: None} def send_fail(self, htlc_id: int) -> None: self.log[REMOTE]['fails'][htlc_id] = {LOCAL: None, REMOTE: self.ctn_latest(REMOTE) + 1} def recv_fail(self, htlc_id: int) -> None: self.log[LOCAL]['fails'][htlc_id] = {LOCAL: self.ctn_latest(LOCAL) + 1, REMOTE: None} def send_update_fee(self, feerate: int) -> None: fee_update = FeeUpdate(rate=feerate, ctn_local=None, ctn_remote=self.ctn_latest(REMOTE) + 1) self._new_feeupdate(fee_update, subject=LOCAL) def recv_update_fee(self, feerate: int) -> None: fee_update = FeeUpdate(rate=feerate, ctn_local=self.ctn_latest(LOCAL) + 1, ctn_remote=None) self._new_feeupdate(fee_update, subject=REMOTE) def _new_feeupdate(self, fee_update: FeeUpdate, subject: HTLCOwner) -> None: # overwrite last fee update if not yet committed to by anyone; otherwise append d = self.log[subject]['fee_updates'] #assert type(d) is StoredDict n = len(d) last_fee_update = d[n-1] if (last_fee_update.ctn_local is None or last_fee_update.ctn_local > self.ctn_latest(LOCAL)) \ and (last_fee_update.ctn_remote is None or last_fee_update.ctn_remote > self.ctn_latest(REMOTE)): d[n-1] = fee_update else: d[n] = fee_update def send_ctx(self) -> None: assert self.ctn_latest(REMOTE) == self.ctn_oldest_unrevoked(REMOTE), (self.ctn_latest(REMOTE), self.ctn_oldest_unrevoked(REMOTE)) self._set_revack_pending(REMOTE, True) def recv_ctx(self) -> None: assert self.ctn_latest(LOCAL) == self.ctn_oldest_unrevoked(LOCAL), (self.ctn_latest(LOCAL), self.ctn_oldest_unrevoked(LOCAL)) self._set_revack_pending(LOCAL, True) def send_rev(self) -> None: self.log[LOCAL]['ctn'] += 1 self._set_revack_pending(LOCAL, False) # htlcs for ctns in self.log[REMOTE]['locked_in'].values(): if ctns[REMOTE] is None and ctns[LOCAL] <= self.ctn_latest(LOCAL): ctns[REMOTE] = self.ctn_latest(REMOTE) + 1 for log_action in ('settles', 'fails'): for ctns in self.log[LOCAL][log_action].values(): if ctns[REMOTE] is None and ctns[LOCAL] <= self.ctn_latest(LOCAL): ctns[REMOTE] = self.ctn_latest(REMOTE) + 1 # fee updates for k, fee_update in list(self.log[REMOTE]['fee_updates'].items()): if fee_update.ctn_remote is None and fee_update.ctn_local <= self.ctn_latest(LOCAL): fee_update.ctn_remote = self.ctn_latest(REMOTE) + 1 def recv_rev(self) -> None: self.log[REMOTE]['ctn'] += 1 self._set_revack_pending(REMOTE, False) # htlcs for ctns in self.log[LOCAL]['locked_in'].values(): if ctns[LOCAL] is None and ctns[REMOTE] <= self.ctn_latest(REMOTE): ctns[LOCAL] = self.ctn_latest(LOCAL) + 1 for log_action in ('settles', 'fails'): for ctns in self.log[REMOTE][log_action].values(): if ctns[LOCAL] is None and ctns[REMOTE] <= self.ctn_latest(REMOTE): ctns[LOCAL] = self.ctn_latest(LOCAL) + 1 # fee updates for k, fee_update in list(self.log[LOCAL]['fee_updates'].items()): if fee_update.ctn_local is None and fee_update.ctn_remote <= self.ctn_latest(REMOTE): fee_update.ctn_local = self.ctn_latest(LOCAL) + 1 # no need to keep local update raw msgs anymore, they have just been ACKed. self.log['unacked_local_updates2'].pop(self.log[REMOTE]['ctn'], None) def discard_unsigned_remote_updates(self): """Discard updates sent by the remote, that the remote itself did not yet sign (i.e. there was no corresponding commitment_signed msg) """ # htlcs added for htlc_id, ctns in list(self.log[REMOTE]['locked_in'].items()): if ctns[LOCAL] > self.ctn_latest(LOCAL): del self.log[REMOTE]['locked_in'][htlc_id] del self.log[REMOTE]['adds'][htlc_id] if self.log[REMOTE]['locked_in']: self.log[REMOTE]['next_htlc_id'] = max([int(x) for x in self.log[REMOTE]['locked_in'].keys()]) + 1 else: self.log[REMOTE]['next_htlc_id'] = 0 # htlcs removed for log_action in ('settles', 'fails'): for htlc_id, ctns in list(self.log[LOCAL][log_action].items()): if ctns[LOCAL] > self.ctn_latest(LOCAL): del self.log[LOCAL][log_action][htlc_id] # fee updates for k, fee_update in list(self.log[REMOTE]['fee_updates'].items()): if fee_update.ctn_local > self.ctn_latest(LOCAL): self.log[REMOTE]['fee_updates'].pop(k) def store_local_update_raw_msg(self, raw_update_msg: bytes, *, is_commitment_signed: bool) -> None: """We need to be able to replay unacknowledged updates we sent to the remote in case of disconnections. Hence, raw update and commitment_signed messages are stored temporarily (until they are acked).""" # self.log['unacked_local_updates2'][ctn_idx] is a list of raw messages # containing some number of updates and then a single commitment_signed if is_commitment_signed: ctn_idx = self.ctn_latest(REMOTE) else: ctn_idx = self.ctn_latest(REMOTE) + 1 l = self.log['unacked_local_updates2'].get(ctn_idx, []) l.append(raw_update_msg.hex()) self.log['unacked_local_updates2'][ctn_idx] = l def get_unacked_local_updates(self) -> Dict[int, Sequence[bytes]]: #return self.log['unacked_local_updates2'] return {int(ctn): [bfh(msg) for msg in messages] for ctn, messages in self.log['unacked_local_updates2'].items()} ##### Queries re HTLCs: def htlcs_by_direction(self, subject: HTLCOwner, direction: Direction, ctn: int = None) -> Dict[int, UpdateAddHtlc]: """Return the dict of received or sent (depending on direction) HTLCs in subject's ctx at ctn, keyed by htlc_id. direction is relative to subject! """ assert type(subject) is HTLCOwner assert type(direction) is Direction if ctn is None: ctn = self.ctn_oldest_unrevoked(subject) d = {} # subject's ctx # party is the proposer of the HTLCs party = subject if direction == SENT else subject.inverted() settles = self.log[party]['settles'] fails = self.log[party]['fails'] for htlc_id, ctns in self.log[party]['locked_in'].items(): if ctns[subject] is not None and ctns[subject] <= ctn: not_settled = htlc_id not in settles or settles[htlc_id][subject] is None or settles[htlc_id][subject] > ctn not_failed = htlc_id not in fails or fails[htlc_id][subject] is None or fails[htlc_id][subject] > ctn if not_settled and not_failed: d[htlc_id] = self.log[party]['adds'][htlc_id] return d def htlcs(self, subject: HTLCOwner, ctn: int = None) -> Sequence[Tuple[Direction, UpdateAddHtlc]]: """Return the list of HTLCs in subject's ctx at ctn.""" assert type(subject) is HTLCOwner if ctn is None: ctn = self.ctn_oldest_unrevoked(subject) l = [] l += [(SENT, x) for x in self.htlcs_by_direction(subject, SENT, ctn).values()] l += [(RECEIVED, x) for x in self.htlcs_by_direction(subject, RECEIVED, ctn).values()] return l def get_htlcs_in_oldest_unrevoked_ctx(self, subject: HTLCOwner) -> Sequence[Tuple[Direction, UpdateAddHtlc]]: assert type(subject) is HTLCOwner ctn = self.ctn_oldest_unrevoked(subject) return self.htlcs(subject, ctn) def get_htlcs_in_latest_ctx(self, subject: HTLCOwner) -> Sequence[Tuple[Direction, UpdateAddHtlc]]: assert type(subject) is HTLCOwner ctn = self.ctn_latest(subject) return self.htlcs(subject, ctn) def get_htlcs_in_next_ctx(self, subject: HTLCOwner) -> Sequence[Tuple[Direction, UpdateAddHtlc]]: assert type(subject) is HTLCOwner ctn = self.ctn_latest(subject) + 1 return self.htlcs(subject, ctn) def was_htlc_preimage_released(self, *, htlc_id: int, htlc_sender: HTLCOwner) -> bool: settles = self.log[htlc_sender]['settles'] if htlc_id not in settles: return False return settles[htlc_id][htlc_sender] is not None def all_settled_htlcs_ever_by_direction(self, subject: HTLCOwner, direction: Direction, ctn: int = None) -> Sequence[UpdateAddHtlc]: """Return the list of all HTLCs that have been ever settled in subject's ctx up to ctn, filtered to only "direction". """ assert type(subject) is HTLCOwner if ctn is None: ctn = self.ctn_oldest_unrevoked(subject) # subject's ctx # party is the proposer of the HTLCs party = subject if direction == SENT else subject.inverted() d = [] for htlc_id, ctns in self.log[party]['settles'].items(): if ctns[subject] is not None and ctns[subject] <= ctn: d.append(self.log[party]['adds'][htlc_id]) return d def all_settled_htlcs_ever(self, subject: HTLCOwner, ctn: int = None) \ -> Sequence[Tuple[Direction, UpdateAddHtlc]]: """Return the list of all HTLCs that have been ever settled in subject's ctx up to ctn. """ assert type(subject) is HTLCOwner if ctn is None: ctn = self.ctn_oldest_unrevoked(subject) sent = [(SENT, x) for x in self.all_settled_htlcs_ever_by_direction(subject, SENT, ctn)] received = [(RECEIVED, x) for x in self.all_settled_htlcs_ever_by_direction(subject, RECEIVED, ctn)] return sent + received def received_in_ctn(self, ctn: int) -> Sequence[UpdateAddHtlc]: return [self.log[REMOTE]['adds'][htlc_id] for htlc_id, ctns in self.log[REMOTE]['settles'].items() if ctns[LOCAL] == ctn] def sent_in_ctn(self, ctn: int) -> Sequence[UpdateAddHtlc]: return [self.log[LOCAL]['adds'][htlc_id] for htlc_id, ctns in self.log[LOCAL]['settles'].items() if ctns[LOCAL] == ctn] ##### Queries re Fees: def get_feerate(self, subject: HTLCOwner, ctn: int) -> int: """Return feerate used in subject's commitment txn at ctn.""" ctn = max(0, ctn) # FIXME rm this # only one party can update fees; use length of logs to figure out which: assert not (len(self.log[LOCAL]['fee_updates']) > 1 and len(self.log[REMOTE]['fee_updates']) > 1) fee_log = self.log[LOCAL]['fee_updates'] # type: Sequence[FeeUpdate] if len(self.log[REMOTE]['fee_updates']) > 1: fee_log = self.log[REMOTE]['fee_updates'] # binary search left = 0 right = len(fee_log) while True: i = (left + right) // 2 ctn_at_i = fee_log[i].ctn_local if subject==LOCAL else fee_log[i].ctn_remote if right - left <= 1: break if ctn_at_i is None: # Nones can only be on the right end right = i continue if ctn_at_i <= ctn: # among equals, we want the rightmost left = i else: right = i assert ctn_at_i <= ctn return fee_log[i].rate def get_feerate_in_oldest_unrevoked_ctx(self, subject: HTLCOwner) -> int: return self.get_feerate(subject=subject, ctn=self.ctn_oldest_unrevoked(subject)) def get_feerate_in_latest_ctx(self, subject: HTLCOwner) -> int: return self.get_feerate(subject=subject, ctn=self.ctn_latest(subject)) def get_feerate_in_next_ctx(self, subject: HTLCOwner) -> int: return self.get_feerate(subject=subject, ctn=self.ctn_latest(subject) + 1)