create_channel_storage: return dict instead of StoredDict

we should avoid dangling StoredDict; this does not make sense
if the DB is not in memory.

(a unit test with dangling StoredDict is in the levelDB branch)

Author: ecdsa

electrum/lnchannel.py

@@ -26,6 +26,7 @@
     Iterable, Sequence, TYPE_CHECKING, Iterator, Union, Mapping)
 from abc import ABC, abstractmethod
 import itertools
+import threading
 
 from aiorpcx import NetAddress
 
@@ -790,7 +791,7 @@ def __init__(
         Logger.__init__(self)  # should be after short_channel_id is set
         self.lnworker = lnworker
         self.storage = state
-        self.db_lock = self.storage.lock
+        self.db_lock = threading.RLock() if isinstance(self.storage, dict) else self.storage.lock
         self.config = {}
         self.config[LOCAL] = state["local_config"]
         self.config[REMOTE] = state["remote_config"]

electrum/lnhtlc.py

@@ -1,5 +1,6 @@
 from copy import deepcopy
 from typing import Sequence, Tuple, Dict, TYPE_CHECKING, Set
+import threading
 
 from .lnutil import SENT, RECEIVED, LOCAL, REMOTE, HTLCOwner, UpdateAddHtlc, Direction, FeeUpdate
 from .util import bfh, with_lock
@@ -21,7 +22,7 @@
 
 class HTLCManager:
 
-    def __init__(self, log: 'StoredDict', *, initiator=None, initial_feerate=None):
+    def __init__(self, log: 'StoredDict', *, initiator=None, initial_feerate=None, lock=None):
 
         if len(log) == 0:
             # note: "htlc_id" keys in dict are str! but due to json_db magic they can *almost* be treated as int...
@@ -41,7 +42,7 @@ def __init__(self, log: 'StoredDict', *, initiator=None, initial_feerate=None):
         # lnchannel sometimes calls us with Channel.db_lock (== log.lock) already taken,
         # and we ourselves often take log.lock (via StoredDict.__getitem__).
         # Hence, to avoid deadlocks, we reuse this same lock.
-        self.lock = log.lock
+        self.lock = lock if lock else threading.RLock()
 
         self._init_maybe_active_htlc_ids()
 

electrum/lnpeer.py

@@ -52,7 +52,6 @@
 from .lntransport import LNTransport, LNTransportBase, LightningPeerConnectionClosed, HandshakeFailed
 from .lnmsg import encode_msg, decode_msg, UnknownOptionalMsgType, FailedToParseMsg
 from .interface import GracefulDisconnect
-from .json_db import StoredDict
 from .invoices import PR_PAID
 from .fee_policy import FEE_LN_ETA_TARGET, FEERATE_PER_KW_MIN_RELAY_LIGHTNING
 from .channel_db import FLAG_DIRECTION
@@ -1235,7 +1234,7 @@ def create_channel_storage(self, channel_id, outpoint, local_config, remote_conf
             "revocation_store": {},
             "channel_type": channel_type,
         }
-        return StoredDict(chan_dict, self.lnworker.db)
+        return chan_dict
 
     @non_blocking_msg_handler
     async def on_open_channel(self, payload):

electrum/lnworker.py

@@ -1662,9 +1662,15 @@ def add_channel(self, chan: Channel):
         self.lnwatcher.add_channel(chan)
 
     def add_new_channel(self, chan: Channel):
-        self.add_channel(chan)
+        # delete the old channel object, becauses it uses a dict
+        assert type(chan.storage) is dict
+        channel_id = chan.channel_id.hex()
         channels_db = self.db.get_dict('channels')
-        channels_db[chan.channel_id.hex()] = chan.storage
+        channels_db[channel_id] = chan.storage
+        del chan
+        storage = channels_db[channel_id] # StoredDict
+        chan = Channel(storage, lnworker=self)
+        self.add_channel(chan)
         self.wallet.set_reserved_addresses_for_chan(chan, reserved=True)
         try:
             self.save_channel(chan)

electrum/stored_dict.py

@@ -138,14 +138,14 @@ def lock(self):
 
     @property
     def path(self) -> Sequence[_FLEX_KEY] | None:
-        # return None iff we are pruned from root
+        # raises iff we are pruned from root
         x = self
         s = [x._key]
         while x._parent is not None:
             x = x._parent
             s = [x._key] + s
         if x._key != '':
-            return None
+            raise KeyError()
         assert self._db is not None
         return s