Handle network outages

Quote queries will hang indefinitely when the network goes down.
Instead poll for network reestablishment such that roaming on
wifi is supported and real-time feeds will resume once the network is
back.
kivy_mainline_and_py3.8
Tyler Goodlet 2018-03-31 12:02:22 -04:00
parent 2b51e84a3c
commit 01cfbbdd64
1 changed files with 23 additions and 1 deletions

View File

@ -3,6 +3,8 @@ Core broker-daemon tasks and API.
"""
import time
import inspect
from functools import partial
import socket
from types import ModuleType
from typing import AsyncContextManager
@ -44,6 +46,17 @@ async def quote(brokermod: ModuleType, tickers: [str]) -> dict:
return results
async def wait_for_network(get_quotes, sleep=1):
"""Wait until the network comes back up.
"""
while True:
try:
return await get_quotes()
except socket.gaierror:
log.warn(f"Network is down waiting for reestablishment...")
await trio.sleep(sleep)
async def poll_tickers(
client: 'Client',
quoter: AsyncContextManager,
@ -64,7 +77,16 @@ async def poll_tickers(
async with quoter(client, tickers) as get_quotes:
while True: # use an event here to trigger exit?
prequote_start = time.time()
with trio.move_on_after(3) as cancel_scope:
quotes = await get_quotes(tickers)
cancelled = cancel_scope.cancelled_caught
if cancelled:
log.warn("Quote query timed out after 3 seconds, retrying...")
# handle network outages by idling until response is received
quotes = await wait_for_network(partial(get_quotes, tickers))
postquote_start = time.time()
payload = {}
for symbol, quote in quotes.items():