flask request close insanity

app.py

import time
from flask import Flask, Response, current_app


class Stream(object):

    def __init__(self, string):
        self.bytes = 0
        self.string = string

    def __iter__(self):
        while True:
            self.bytes += len(self.string)
            yield self.string

app = Flask(__name__)
app.foos = 0


def make_callback(stream):
    t = time.time()
    foos = current_app.foos
    def callback():
        print "closing!"
        print "bytes streamed: {}".format(stream.bytes)
        print t, foos
    return callback


@app.route("/<where>")
def route(where):
    if where == "foo":
        current_app.foos += 1
    stream = Stream(where)
    resp = Response(stream)
    resp.call_on_close(make_callback(stream))
    return resp


app.run()