Adds a new test case for e2e trampoline payment, where there are multiple
Trampoline Forwarders which themselves are not directly connected.
This adds a regression test for https://github.com/spesmilo/electrum/pull/9431dffdebf778
- Wait until HTLCs are irrevocably removed before cleaning up their
data structures (MPP and forwarding)
- keep methods maybe_cleanup_mpp and maybe_cleanup_forwarding separate
- perform cleanup in htlc_switch, so that process_unfulfilled_htlc
has less side effects
- In htlc_switch, we blank the onion_packet_hex field to signal that
an HTLC has been processed. An item of chan.unfulfilled_htlcs may
go through 4 stages:
- 1. not forwarded yet: (None, onion_packet_hex)
- 2. forwarded: (forwarding_key, onion_packet_hex)
- 3. processed: (forwarding_key, None), not irrevocably removed yet
- 4. done: (forwarding_key, None), irrevocably removed
- in test_lnpeer, an extra iteration of htlc_switch has been added to
trampoline forwarding tests
If we accept a MPP and we forward the payment (trampoline or swap),
we need to persist the payment accepted status, or we might wrongly
release htlcs on the next restart.
lnworker.received_mpp_htlcs used to be cleaned up in maybe_cleanup_forwarding,
which only applies to forwarded payments. However, since we now
persist this dict, we need to clean it up also in the case of
payments received by us. This part of maybe_cleanup_forwarding has
been migrated to lnworker.maybe_cleanup_mpp
This will be useful if we decide to ship lntransport as a separate
package. It is also a conceptual cleanup.
Notes:
- lntransport still requires crypto.py
- parsing node id from a bolt11 invoice is not supported.
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.
