Menu
I have a bunch of long running scripts which do some number crunching and as they run write output to the console via print I want to invoke these scripts from a browser, and display the progress in the browser as they run. I'm currently playing with bottle and am working through this primer http://bottlepy.org/docs/dev/async.html# which is rather neat.
I'd like to try Event Callbacks http://bottlepy.org/docs/dev/async.html#event-callbacks as this seems to exactly match my problem, the script would run as an AsyncWorker (ideally managed by some message queue to limit the number running at any one instance) and periodically write back it's state. But I cannot figure out what SomeAsyncWorker() is - is it a tornado class or a gevent class I have to implement or something else?
@route('/fetch')
def fetch():
body = gevent.queue.Queue()
worker = SomeAsyncWorker()
worker.on_data(body.put)
worker.on_finish(lambda: body.put(StopIteration))
worker.start()
return body
282
I've found one way of doing this using gevent.queue here http://toastdriven.com/blog/2011/jul/31/gevent-long-polling-you/ which shouldn't be hard to adapt to work with bottle
# wsgi_longpolling/better_responses.py
from gevent import monkey
monkey.patch_all()
import datetime
import time
from gevent import Greenlet
from gevent import pywsgi
from gevent import queue
def current_time(body):
current = start = datetime.datetime.now()
end = start + datetime.timedelta(seconds=60)
while current < end:
current = datetime.datetime.now()
body.put('<div>%s</div>' % current.strftime("%Y-%m-%d %I:%M:%S"))
time.sleep(1)
body.put('</body></html>')
body.put(StopIteration)
def handle(environ, start_response):
start_response('200 OK', [('Content-Type', 'text/html')])
body = queue.Queue()
body.put(' ' * 1000)
body.put("<html><body><h1>Current Time:</h1>")
g = Greenlet.spawn(current_time, body)
return body
server = pywsgi.WSGIServer(('127.0.0.1', 1234), handle)
print "Serving on http://127.0.0.1:1234..."
server.serve_forever()
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With