gistfile1.py

# -*- coding: utf-8 -*-

from google.appengine.api import taskqueue
from google.appengine.ext import db
from google.appengine.ext import webapp
from google.appengine.ext.webapp import template
from google.appengine.ext.webapp.util import run_wsgi_app

class Counter(db.Model):
    count = db.IntegerProperty(indexed=False)

class CounterHandler(webapp.RequestHandler):
    def get(self):
        self.response.out.write(template.render('counters.html',
                                                {'counters': Counter.all()}))

    def post(self):
        key = self.request.get('key')

        # Add the task to the default queue.
        taskqueue.add(url='/worker', params={'key': key})

        self.redirect('/')

class CounterWorker(webapp.RequestHandler):
    def post(self): # should run at most 1/s
        key = self.request.get('key')
        def txn():
            counter = Counter.get_by_key_name(key)
            if counter is None:
                counter = Counter(key_name=key, count=1)
            else:
                counter.count += 1
            counter.put()
        db.run_in_transaction(txn)

def main():
    run_wsgi_app(webapp.WSGIApplication([
        ('/', CounterHandler),
        ('/worker', CounterWorker),
    ]))

if __name__ == '__main__':
    main()