commit 815079efe025d33bbecc17ba0959f233f0e54376
parent 5b1a5e8786664eba0476453de166243073b62fd9
Author: SomberNight <somber.night@protonmail.com>
Date: Tue, 17 Apr 2018 20:01:51 +0200
refactor storage of channels, path finding
Diffstat:
2 files changed, 170 insertions(+), 95 deletions(-)
diff --git a/lib/lnbase.py b/lib/lnbase.py
@@ -419,10 +419,8 @@ class Peer(PrintError):
self.localfeatures = (0x08 if request_initial_sync else 0)
# view of the network
self.nodes = {} # received node announcements
- self.channels = {} # received channel announcements
- self.channel_u_origin = {}
- self.channel_u_final = {}
- self.graph_of_payment_channels = defaultdict(set) # node -> short_channel_id
+ self.channel_db = ChannelDB()
+ self.path_finder = LNPathFinder(self.channel_db)
def diagnostic_name(self):
return self.host
@@ -541,8 +539,8 @@ class Peer(PrintError):
def on_funding_signed(self, payload):
sig = payload['signature']
channel_id = payload['channel_id']
- tx = self.channels[channel_id]
- self.network.broadcast(tx)
+ #tx = self.channels[channel_id] # FIXME
+ #self.network.broadcast(tx)
def on_funding_signed(self, payload):
self.funding_signed[payload["temporary_channel_id"]].set_result(payload)
@@ -588,99 +586,14 @@ class Peer(PrintError):
pass
def on_channel_update(self, payload):
- flags = int.from_bytes(payload['flags'], byteorder="big")
- direction = bool(flags & 1)
- short_channel_id = payload['short_channel_id']
- if direction == 0:
- self.channel_u_origin[short_channel_id] = payload
- else:
- self.channel_u_final[short_channel_id] = payload
- self.print_error('channel update', binascii.hexlify(short_channel_id), flags)
+ self.channel_db.on_channel_update(payload)
def on_channel_announcement(self, payload):
- short_channel_id = payload['short_channel_id']
- self.print_error('channel announcement', binascii.hexlify(short_channel_id))
- self.channels[short_channel_id] = payload
- self.add_channel_to_graph(payload)
-
- def add_channel_to_graph(self, payload):
- node1 = payload['node_id_1']
- node2 = payload['node_id_2']
- channel_id = payload['short_channel_id']
- self.graph_of_payment_channels[node1].add(channel_id)
- self.graph_of_payment_channels[node2].add(channel_id)
+ self.channel_db.on_channel_announcement(payload)
#def open_channel(self, funding_sat, push_msat):
# self.send_message(gen_msg('open_channel', funding_satoshis=funding_sat, push_msat=push_msat))
- @profiler
- def find_route_for_payment(self, from_node_id, to_node_id, amount_msat=None):
- """Return a route between from_node_id and to_node_id.
-
- Returns a list of (node_id, short_channel_id) representing a path.
- To get from node ret[n][0] to ret[n+1][0], use channel ret[n][1]
- """
- # TODO find multiple paths??
-
- def edge_cost(short_channel_id, direction):
- """Heuristic cost of going through a channel.
- direction: 0 or 1. --- 0 means node_id_1 -> node_id_2
- """
- channel_updates = self.channel_u_origin if direction == 0 else self.channel_u_final
- try:
- cltv_expiry_delta = channel_updates[short_channel_id]['cltv_expiry_delta']
- htlc_minimum_msat = channel_updates[short_channel_id]['htlc_minimum_msat']
- fee_base_msat = channel_updates[short_channel_id]['fee_base_msat']
- fee_proportional_millionths = channel_updates[short_channel_id]['fee_proportional_millionths']
- except KeyError:
- return float('inf') # can't use this channel
- if amount_msat is not None and amount_msat < htlc_minimum_msat:
- return float('inf') # can't use this channel
- amt = amount_msat or 50000 * 1000 # guess for typical payment amount
- fee_msat = fee_base_msat + amt * fee_proportional_millionths / 1000000
- # TODO revise
- # paying 10 more satoshis ~ waiting one more block
- fee_cost = fee_msat / 1000 / 10
- cltv_cost = cltv_expiry_delta
- return cltv_cost + fee_cost + 1
-
- # run Dijkstra
- distance_from_start = defaultdict(lambda: float('inf'))
- distance_from_start[from_node_id] = 0
- prev_node = {}
- nodes_to_explore = queue.PriorityQueue()
- nodes_to_explore.put((0, from_node_id))
-
- while nodes_to_explore.qsize() > 0:
- dist_to_cur_node, cur_node = nodes_to_explore.get()
- if cur_node == to_node_id:
- break
- if dist_to_cur_node != distance_from_start[cur_node]:
- # queue.PriorityQueue does not implement decrease_priority,
- # so instead of decreasing priorities, we add items again into the queue.
- # so there are duplicates in the queue, that we discard now:
- continue
- for edge in self.graph_of_payment_channels[cur_node]:
- node1 = self.channels[edge]['node_id_1']
- node2 = self.channels[edge]['node_id_2']
- neighbour, direction = (node1, 1) if node1 != cur_node else (node2, 0)
- alt_dist_to_neighbour = distance_from_start[cur_node] + edge_cost(edge, direction)
- if alt_dist_to_neighbour < distance_from_start[neighbour]:
- distance_from_start[neighbour] = alt_dist_to_neighbour
- prev_node[neighbour] = cur_node, edge
- nodes_to_explore.put((alt_dist_to_neighbour, neighbour))
- else:
- return None # no path found
-
- # backtrack from end to start
- cur_node = to_node_id
- path = [(cur_node, None)]
- while cur_node != from_node_id:
- cur_node, edge_taken = prev_node[cur_node]
- path += [(cur_node, edge_taken)]
- path.reverse()
- return path
-
@aiosafe
async def main_loop(self):
self.reader, self.writer = await asyncio.open_connection(self.host, self.port)
@@ -792,3 +705,165 @@ class LNWorker:
# todo: get utxo from wallet
# submit coro to asyncio main loop
self.peer.open_channel()
+
+
+class ChannelInfo(PrintError):
+
+ def __init__(self, channel_announcement_payload):
+ self.channel_id = channel_announcement_payload['short_channel_id']
+ self.node_id_1 = channel_announcement_payload['node_id_1']
+ self.node_id_2 = channel_announcement_payload['node_id_2']
+
+ self.capacity_sat = None
+ self.policy_node1 = None
+ self.policy_node2 = None
+
+ def set_capacity(self, capacity):
+ # TODO call this after looking up UTXO for funding txn on chain
+ self.capacity_sat = capacity
+
+ def on_channel_update(self, msg_payload):
+ assert self.channel_id == msg_payload['short_channel_id']
+ flags = int.from_bytes(msg_payload['flags'], byteorder="big")
+ direction = bool(flags & 1)
+ if direction == 0:
+ self.policy_node1 = ChannelInfoDirectedPolicy(msg_payload)
+ else:
+ self.policy_node2 = ChannelInfoDirectedPolicy(msg_payload)
+ self.print_error('channel update', binascii.hexlify(self.channel_id), flags)
+
+ def get_policy_for_node(self, node_id):
+ if node_id == self.node_id_1:
+ return self.policy_node1
+ elif node_id == self.node_id_2:
+ return self.policy_node2
+ else:
+ raise Exception('node_id {} not in channel {}'.format(node_id, self.channel_id))
+
+
+class ChannelInfoDirectedPolicy:
+
+ def __init__(self, channel_update_payload):
+ self.cltv_expiry_delta = channel_update_payload['cltv_expiry_delta']
+ self.htlc_minimum_msat = channel_update_payload['htlc_minimum_msat']
+ self.fee_base_msat = channel_update_payload['fee_base_msat']
+ self.fee_proportional_millionths = channel_update_payload['fee_proportional_millionths']
+
+
+class ChannelDB(PrintError):
+
+ def __init__(self):
+ self._id_to_channel_info = {}
+ self._channels_for_node = defaultdict(set) # node -> set(short_channel_id)
+
+ def get_channel_info(self, channel_id):
+ return self._id_to_channel_info.get(channel_id, None)
+
+ def get_channels_for_node(self, node_id):
+ """Returns the set of channels that have node_id as one of the endpoints."""
+ return self._channels_for_node[node_id]
+
+ def on_channel_announcement(self, msg_payload):
+ short_channel_id = msg_payload['short_channel_id']
+ self.print_error('channel announcement', binascii.hexlify(short_channel_id))
+ channel_info = ChannelInfo(msg_payload)
+ self._id_to_channel_info[short_channel_id] = channel_info
+ self._channels_for_node[channel_info.node_id_1].add(short_channel_id)
+ self._channels_for_node[channel_info.node_id_2].add(short_channel_id)
+
+ def on_channel_update(self, msg_payload):
+ short_channel_id = msg_payload['short_channel_id']
+ self._id_to_channel_info[short_channel_id].on_channel_update(msg_payload)
+
+ def remove_channel(self, short_channel_id):
+ try:
+ channel_info = self._id_to_channel_info[short_channel_id]
+ except KeyError:
+ self.print_error('cannot find channel {}'.format(short_channel_id))
+ return
+ self._id_to_channel_info.pop(short_channel_id, None)
+ for node in (channel_info.node_id_1, channel_info.node_id_2):
+ try:
+ self._channels_for_node[node].remove(short_channel_id)
+ except KeyError:
+ pass
+
+
+class LNPathFinder(PrintError):
+
+ def __init__(self, channel_db):
+ self.channel_db = channel_db
+
+ def _edge_cost(self, short_channel_id, start_node, payment_amt_msat):
+ """Heuristic cost of going through a channel.
+ direction: 0 or 1. --- 0 means node_id_1 -> node_id_2
+ """
+ channel_info = self.channel_db.get_channel_info(short_channel_id)
+ if channel_info is None:
+ return float('inf')
+
+ channel_policy = channel_info.get_policy_for_node(start_node)
+ cltv_expiry_delta = channel_policy.cltv_expiry_delta
+ htlc_minimum_msat = channel_policy.htlc_minimum_msat
+ fee_base_msat = channel_policy.fee_base_msat
+ fee_proportional_millionths = channel_policy.fee_proportional_millionths
+ if payment_amt_msat is not None:
+ if payment_amt_msat < htlc_minimum_msat:
+ return float('inf') # payment amount too little
+ if channel_info.capacity_sat is not None and \
+ payment_amt_msat // 1000 > channel_info.capacity_sat:
+ return float('inf') # payment amount too large
+ amt = payment_amt_msat or 50000 * 1000 # guess for typical payment amount
+ fee_msat = fee_base_msat + amt * fee_proportional_millionths / 1000000
+ # TODO revise
+ # paying 10 more satoshis ~ waiting one more block
+ fee_cost = fee_msat / 1000 / 10
+ cltv_cost = cltv_expiry_delta
+ return cltv_cost + fee_cost + 1
+
+ @profiler
+ def find_path_for_payment(self, from_node_id, to_node_id, amount_msat=None):
+ """Return a path between from_node_id and to_node_id.
+
+ Returns a list of (node_id, short_channel_id) representing a path.
+ To get from node ret[n][0] to ret[n+1][0], use channel ret[n][1]
+ """
+ # TODO find multiple paths??
+
+ # run Dijkstra
+ distance_from_start = defaultdict(lambda: float('inf'))
+ distance_from_start[from_node_id] = 0
+ prev_node = {}
+ nodes_to_explore = queue.PriorityQueue()
+ nodes_to_explore.put((0, from_node_id))
+
+ while nodes_to_explore.qsize() > 0:
+ dist_to_cur_node, cur_node = nodes_to_explore.get()
+ if cur_node == to_node_id:
+ break
+ if dist_to_cur_node != distance_from_start[cur_node]:
+ # queue.PriorityQueue does not implement decrease_priority,
+ # so instead of decreasing priorities, we add items again into the queue.
+ # so there are duplicates in the queue, that we discard now:
+ continue
+ for edge_channel_id in self.channel_db.get_channels_for_node(cur_node):
+ channel_info = self.channel_db.get_channel_info(edge_channel_id)
+ node1, node2 = channel_info.node_id_1, channel_info.node_id_2
+ neighbour = node2 if node1 == cur_node else node1
+ alt_dist_to_neighbour = distance_from_start[cur_node] \
+ + self._edge_cost(edge_channel_id, cur_node, amount_msat)
+ if alt_dist_to_neighbour < distance_from_start[neighbour]:
+ distance_from_start[neighbour] = alt_dist_to_neighbour
+ prev_node[neighbour] = cur_node, edge_channel_id
+ nodes_to_explore.put((alt_dist_to_neighbour, neighbour))
+ else:
+ return None # no path found
+
+ # backtrack from end to start
+ cur_node = to_node_id
+ path = [(cur_node, None)]
+ while cur_node != from_node_id:
+ cur_node, edge_taken = prev_node[cur_node]
+ path += [(cur_node, edge_taken)]
+ path.reverse()
+ return path
diff --git a/lib/tests/test_lnbase.py b/lib/tests/test_lnbase.py
@@ -181,7 +181,7 @@ class Test_LNBase(unittest.TestCase):
# local_signature = 30440220549e80b4496803cbc4a1d09d46df50109f546d43fbbf86cd90b174b1484acd5402205f12a4f995cb9bded597eabfee195a285986aa6d93ae5bb72507ebc6a4e2349e
output_htlc_success_tx_4 = "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"
- def test_find_route_for_payment(self):
+ def test_find_path_for_payment(self):
p = Peer('', 0, 'a')
p.on_channel_announcement({'node_id_1': 'b', 'node_id_2': 'c', 'short_channel_id': bfh('0000000000000001')})
p.on_channel_announcement({'node_id_1': 'b', 'node_id_2': 'e', 'short_channel_id': bfh('0000000000000002')})
@@ -201,7 +201,7 @@ class Test_LNBase(unittest.TestCase):
p.on_channel_update({'short_channel_id': bfh('0000000000000005'), 'flags': b'1', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 999})
p.on_channel_update({'short_channel_id': bfh('0000000000000006'), 'flags': b'0', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 99999999})
p.on_channel_update({'short_channel_id': bfh('0000000000000006'), 'flags': b'1', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150})
- print(p.find_route_for_payment('a', 'e', 100000))
+ print(p.path_finder.find_path_for_payment('a', 'e', 100000))
def test_key_derivation(self):
# BOLT3, Appendix E
