#!/usr/bin/env python
"""
This is a simple web "crawler" that fetches a bunch of urls using a pool to
control the number of outbound connections. It has as many simultaneously open
connections as coroutines in the pool.

The prints in the body of the fetch function are there to demonstrate that the
requests are truly made in parallel.
"""
import eventlet
from eventlet.green import urllib2


urls = [
    "https://www.google.com/intl/en_ALL/images/logo.gif",
    "http://python.org/images/python-logo.gif",
    "http://us.i1.yimg.com/us.yimg.com/i/ww/beta/y3.gif",
]


def fetch(url):
    print "opening", url
    body = urllib2.urlopen(url).read()
    print "done with", url
    return url, body


pool = eventlet.GreenPool(200)
for url, body in pool.imap(fetch, urls):
    print "got body from", url, "of length", len(body)