network: load gossip db early

The gossip db is loaded early when the network is started to save
time when the gui is locked and a wallet not yet loaded. Side effects
of the LNWallet to start peering when a channel db is loaded is
circumvented.

electrum/channel_db.py

@@ -613,6 +613,8 @@ class ChannelDB(SqlDB):
     @sql
     @profiler
     def load_data(self):
+        if self.data_loaded.is_set():
+            return
         # Note: this method takes several seconds... mostly due to lnmsg.decode_msg being slow.
         #       I believe lnmsg (and lightning.json) will need a rewrite anyway, so instead of tweaking
         #       load_data() here, that should be done. see #6006

electrum/daemon.py

@@ -444,6 +444,9 @@ class Daemon(Logger):
             daemon_jobs.append(self.watchtower.run)
         if self.network:
             self.network.start(jobs=[self.fx.run])
+            # prepare lightning functionality, also load channel db early
+            self.network.maybe_init_lightning()
+            self.network.channel_db.load_data()
 
         self.taskgroup = TaskGroup()
         asyncio.run_coroutine_threadsafe(self._run(jobs=daemon_jobs), self.asyncio_loop)

electrum/gui/qt/__init__.py

@@ -208,7 +208,7 @@ class ElectrumGui(Logger):
         self.app.new_window_signal.emit(path, uri)
 
     def show_lightning_dialog(self):
-        if not self.daemon.network.is_lightning_running():
+        if not self.daemon.network.has_channel_db():
             return
         if not self.lightning_dialog:
             self.lightning_dialog = LightningDialog(self)

electrum/gui/qt/channels_list.py

@@ -79,7 +79,7 @@ class ChannelsList(MyTreeView):
             labels[subject] = label
         status = chan.get_state_for_GUI()
         closed = chan.is_closed()
-        if self.network and self.network.is_lightning_running():
+        if self.network and self.network.has_channel_db():
             node_info = self.parent.network.channel_db.get_node_info_for_node_id(chan.node_id)
             node_alias = (node_info.alias if node_info else '') or ''
         else:

electrum/lnworker.py

@@ -460,7 +460,7 @@ class LNGossip(LNWorker):
         self.has_started = True
 
     async def maintain_db(self):
-        await self.channel_db.load_data()
+        await self.channel_db.data_loaded.wait()
         while True:
             if len(self.unknown_ids) == 0:
                 self.channel_db.prune_old_policies(self.max_age)
@@ -584,6 +584,10 @@ class LNWallet(LNWorker):
 
     def start_network(self, network: 'Network'):
         assert network
+        self.network = network
+        self.config = network.config
+        self.channel_db = self.network.channel_db
+
         self.lnwatcher = LNWalletWatcher(self, network)
         self.lnwatcher.start_network(network)
         self.network = network
@@ -592,7 +596,6 @@ class LNWallet(LNWorker):
         for chan in self.channels.values():
             self.lnwatcher.add_channel(chan.funding_outpoint.to_str(), chan.get_funding_address())
 
-        super().start_network(network)
         for coro in [
                 self.maybe_listen(),
                 self.lnwatcher.on_network_update('network_updated'), # shortcut (don't block) if funding tx locked and verified

electrum/network.py

@@ -344,7 +344,7 @@ class Network(Logger, NetworkRetryManager[ServerAddr]):
         """Our guess whether the device has Internet-connectivity."""
         return self._has_ever_managed_to_connect_to_server
 
-    def is_lightning_running(self):
+    def has_channel_db(self):
         return self.channel_db is not None
 
     def maybe_init_lightning(self):

electrum/wallet.py

@@ -363,7 +363,6 @@ class Abstract_Wallet(AddressSynchronizer, ABC):
         AddressSynchronizer.start_network(self, network)
         if network:
             if self.lnworker:
-                network.maybe_init_lightning()
                 self.lnworker.start_network(network)
                 # only start gossiping when we already have channels
                 if self.db.get('channels'):