tlnbase: add some comments - electrum - Electrum Bitcoin wallet
HTML git clone https://git.parazyd.org/electrum
DIR Log
DIR Files
DIR Refs
DIR Submodules
---
DIR commit fc822ab9278c73cf3c1ec864baf29978fbadb3f8
DIR parent f174609158ab1bd139cd40a15794f10d3cae30f0
HTML Author: Janus <ysangkok@gmail.com>
Date: Wed, 18 Apr 2018 16:14:52 +0200
lnbase: add some comments
Diffstat:
M lib/lnbase.py | 43 ++++++++++++++++++++++++++++++
1 file changed, 43 insertions(+), 0 deletions(-)
---
DIR diff --git a/lib/lnbase.py b/lib/lnbase.py
t@@ -45,6 +45,19 @@ class LightningError(Exception):
message_types = {}
def handlesingle(x, ma):
+ """
+ Evaluate a term of the simple language used
+ to specify lightning message field lengths.
+
+ If `x` is an integer, it is returned as is,
+ otherwise it is treated as a variable and
+ looked up in `ma`.
+
+ It the value in `ma` was no integer, it is
+ assumed big-endian bytes and decoded.
+
+ Returns int
+ """
try:
x = int(x)
except ValueError:
t@@ -56,11 +69,28 @@ def handlesingle(x, ma):
return x
def calcexp(exp, ma):
+ """
+ Evaluate simple mathematical expression given
+ in `exp` with variables assigned in the dict `ma`
+
+ Returns int
+ """
exp = str(exp)
assert "*" not in exp
return sum(handlesingle(x, ma) for x in exp.split("+"))
def make_handler(k, v):
+ """
+ Generate a message handler function (taking bytes)
+ for message type `k` with specification `v`
+
+ Check lib/lightning.json, `k` could be 'init',
+ and `v` could be
+
+ { type: 16, payload: { 'gflen': ..., ... }, ... }
+
+ Returns function taking bytes
+ """
def handler(data):
nonlocal k, v
ma = {}
t@@ -84,6 +114,9 @@ with open(path) as f:
for k in structured:
v = structured[k]
+ # these message types are skipped since their types collide
+ # (for example with pong, which also uses type=19)
+ # we don't need them yet
if k in ["final_incorrect_cltv_expiry", "final_incorrect_htlc_amount"]:
continue
if len(v["payload"]) == 0:
t@@ -103,11 +136,21 @@ for k in structured:
assert message_types[b"\x00\x10"].__name__ == "init_handler"
def decode_msg(data):
+ """
+ Decode Lightning message by reading the first
+ two bytes to determine message type.
+
+ Returns message type string and parsed message contents dict
+ """
typ = data[:2]
k, parsed = message_types[typ](data[2:])
return k, parsed
def gen_msg(msg_type, **kwargs):
+ """
+ Encode kwargs into a Lightning message (bytes)
+ of the type given in the msg_type string
+ """
typ = structured[msg_type]
data = int(typ["type"]).to_bytes(byteorder="big", length=2)
lengths = {}