code refactoring: _maybe_fullfill_htlc, _maybe_forward_htlc

electrum/lnpeer.py

@@ -917,14 +917,16 @@ class Peer(PrintError):
         htlc = {'amount_msat': amount_msat_htlc, 'payment_hash':payment_hash, 'cltv_expiry':cltv_expiry}
         htlc_id = chan.receive_htlc(htlc)
         local_ctn = chan.get_current_ctn(LOCAL)
-        asyncio.ensure_future(self._on_update_add_htlc(chan, local_ctn, htlc_id, htlc, payment_hash, cltv_expiry, amount_msat_htlc, processed_onion))
+        if processed_onion.are_we_final:
+            asyncio.ensure_future(self._maybe_fulfill_htlc(chan, local_ctn, htlc_id, htlc, payment_hash, cltv_expiry, amount_msat_htlc, processed_onion))
+        else:
+            asyncio.ensure_future(self._maybe_forward_htlc(chan, local_ctn, htlc_id, htlc, payment_hash, cltv_expiry, amount_msat_htlc, processed_onion))
 
     @log_exceptions 
-    async def _on_update_add_htlc(self, chan, local_ctn, htlc_id, htlc, payment_hash, cltv_expiry, amount_msat_htlc, processed_onion):
+    async def _maybe_forward_htlc(self, chan, local_ctn, htlc_id, htlc, payment_hash, cltv_expiry, amount_msat_htlc, processed_onion):
         await self.await_local(chan, local_ctn)
         # Forward HTLC
         # FIXME: this is not robust to us going offline before payment is fulfilled
-        if not processed_onion.are_we_final:
         dph = processed_onion.hop_data.per_hop
         next_chan = self.lnworker.get_channel_by_short_id(dph.short_channel_id)
         next_peer = self.lnworker.peers[next_chan.node_id]
@@ -953,9 +955,12 @@ class Peer(PrintError):
         # wait until we get paid
         preimage = await next_peer.payment_preimages[payment_hash].get()
         # fulfill the original htlc
-            await self.fulfill_htlc(chan, htlc_id, preimage)
+        await self._fulfill_htlc(chan, htlc_id, preimage)
         self.print_error("htlc forwarded successfully")
-            return
+
+    @log_exceptions
+    async def _maybe_fulfill_htlc(self, chan, local_ctn, htlc_id, htlc, payment_hash, cltv_expiry, amount_msat_htlc, processed_onion):
+        await self.await_local(chan, local_ctn)
         try:
             preimage, invoice = self.lnworker.get_invoice(payment_hash)
         except UnknownPaymentHash:
@@ -986,12 +991,11 @@ class Peer(PrintError):
             await self.fail_htlc(chan, htlc_id, onion_packet, reason)
             return
         self.network.trigger_callback('htlc_added', UpdateAddHtlc(**htlc, htlc_id=htlc_id), invoice, RECEIVED)
-        # settle htlc
-        if not self.network.config.debug_lightning_do_not_settle:
-            # settle htlc
-            await self.fulfill_htlc(chan, htlc_id, preimage)
+        if self.network.config.debug_lightning_do_not_settle:
+            return
+        await self._fulfill_htlc(chan, htlc_id, preimage)
 
-    async def fulfill_htlc(self, chan: Channel, htlc_id: int, preimage: bytes):
+    async def _fulfill_htlc(self, chan: Channel, htlc_id: int, preimage: bytes):
         chan.settle_htlc(preimage, htlc_id)
         remote_ctn = chan.get_current_ctn(REMOTE)
         self.send_message("update_fulfill_htlc",