from __future__ import absolute_import
import copy
import time
[docs]class Heartbeat(object):
DEFAULT_CONFIG = {
'heartbeat_interval_ms': 3000,
'session_timeout_ms': 30000,
}
def __init__(self, **configs):
self.config = copy.copy(self.DEFAULT_CONFIG)
for key in self.config:
if key in configs:
self.config[key] = configs[key]
assert (self.config['heartbeat_interval_ms']
<= self.config['session_timeout_ms']), (
'Heartbeat interval must be lower than the session timeout')
self.interval = self.config['heartbeat_interval_ms'] / 1000.0
self.timeout = self.config['session_timeout_ms'] / 1000.0
self.last_send = -1 * float('inf')
self.last_receive = -1 * float('inf')
self.last_reset = time.time()
[docs] def sent_heartbeat(self):
self.last_send = time.time()
[docs] def received_heartbeat(self):
self.last_receive = time.time()
[docs] def ttl(self):
last_beat = max(self.last_send, self.last_reset)
return max(0, last_beat + self.interval - time.time())
[docs] def should_heartbeat(self):
return self.ttl() == 0
[docs] def session_expired(self):
last_recv = max(self.last_receive, self.last_reset)
return (time.time() - last_recv) > self.timeout
[docs] def reset_session_timeout(self):
self.last_reset = time.time()