sintonia/python_apps/media-monitor2/media/monitor/watchersyncer.py

167 lines
6.2 KiB
Python

# -*- coding: utf-8 -*-
import time
import copy
from media.monitor.handler import ReportHandler
from media.monitor.log import Loggable
from media.monitor.exceptions import BadSongFile
from media.monitor.eventcontractor import EventContractor
from media.monitor.events import EventProxy
from media.monitor.request import ThreadedRequestSync, RequestSync
from media.saas.thread import InstanceInheritingThread
class TimeoutWatcher(InstanceInheritingThread,Loggable):
"""
The job of this thread is to keep an eye on WatchSyncer and force a
request whenever the requests go over time out
"""
def __init__(self, watcher, timeout=5):
self.logger.info("Created timeout thread...")
super(TimeoutWatcher, self).__init__()
self.watcher = watcher
self.timeout = timeout
def run(self):
# We try to launch a new thread every self.timeout seconds
# so that the people do not have to wait for the queue to fill up
while True:
time.sleep(self.timeout)
# If there is any requests left we launch em. Note that this
# isn't strictly necessary since RequestSync threads already
# chain themselves
if self.watcher.requests_in_queue():
self.logger.info("We have %d requests waiting to be launched" %
self.watcher.requests_left_count())
self.watcher.request_do()
# Same for events, this behaviour is mandatory however.
if self.watcher.events_in_queue():
self.logger.info("We have %d events that are unflushed" %
self.watcher.events_left_count())
self.watcher.flush_events()
class WatchSyncer(ReportHandler,Loggable):
def __init__(self, signal, chunking_number = 100, timeout=15):
self.timeout = float(timeout)
self.chunking_number = int(chunking_number)
self.request_running = False
self.__current_thread = None
self.__requests = []
self.contractor = EventContractor()
self.__reset_queue()
tc = TimeoutWatcher(self, self.timeout)
tc.daemon = True
tc.start()
super(WatchSyncer, self).__init__(signal=signal)
def handle(self, sender, event):
"""
We implement this abstract method from ReportHandler
"""
if hasattr(event, 'pack'):
# We push this event into queue
self.logger.info("Received event '%s'. Path: '%s'" % \
( event.__class__.__name__,
getattr(event,'path','No path exists') ))
try:
# If there is a strange bug anywhere in the code the next line
# should be a suspect
ev = EventProxy(event)
if self.contractor.register(ev): self.push_queue(ev)
#self.push_queue( event )
except BadSongFile as e:
self.fatal_exception("Received bas song file '%s'" % e.path, e)
except Exception as e: self.unexpected_exception(e)
else:
self.logger.info("Received event that does not implement packing.\
Printing its representation:")
self.logger.info( repr(event) )
def requests_left_count(self):
"""
returns the number of requests left in the queue. requests are
functions that create RequestSync threads
"""
return len(self.__requests)
def events_left_count(self):
"""
Returns the number of events left in the queue to create a request
"""
return len(self.__queue)
def push_queue(self, elem):
"""
Added 'elem' to the event queue and launch a request if we are
over the the chunking number
"""
self.logger.info("Added event into queue")
if self.events_left_count() >= self.chunking_number:
self.push_request()
self.request_do() # Launch the request if nothing is running
self.__queue.append(elem)
def flush_events(self):
"""
Force flush the current events held in the queue
"""
self.logger.info("Force flushing events...")
self.push_request()
self.request_do()
def events_in_queue(self):
"""
returns true if there are events in the queue that haven't been
processed yet
"""
return len(self.__queue) > 0
def requests_in_queue(self):
"""
Returns true if there are any requests in the queue. False otherwise.
"""
return len(self.__requests) > 0
def flag_done(self):
"""
called by request thread when it finishes operating
"""
self.request_running = False
self.__current_thread = None
# This call might not be necessary but we would like to get the
# ball running with the requests as soon as possible
if self.requests_in_queue() > 0: self.request_do()
def request_do(self):
"""
launches a request thread only if one is not running right now
"""
if not self.request_running:
self.request_running = True
self.__requests.pop()()
def push_request(self):
"""
Create a request from the current events in the queue and schedule it
"""
self.logger.info("WatchSyncer : Unleashing request")
# want to do request asyncly and empty the queue
requests = copy.copy(self.__queue)
def launch_request():
# Need shallow copy here
t = ThreadedRequestSync( RequestSync.create_with_api_client(
watcher=self, requests=requests) )
self.__current_thread = t
self.__requests.append(launch_request)
self.__reset_queue()
def __reset_queue(self): self.__queue = []
def __del__(self):
#this destructor is completely untested and it's unclear whether
#it's even doing anything useful. consider removing it
if self.events_in_queue():
self.logger.warn("Terminating with events still in the queue...")
if self.requests_in_queue():
self.logger.warn("Terminating with http requests still pending...")