gae utils

gaeutils.py

from google.appengine.ext import db
from google.appengine.api import memcache, users

import logging
import functools
import datetime, time

import sys, os, re
sys.path.append(os.path.dirname(os.path.realpath(__file__)))

IP_LIMIT = 10 # number of times
IP_THROTTLE_TIME = 60 # time in seconds
IP_THROTTLE_NS = 'ipthrottle'
EMAIL_RE = re.compile('[a-zA-Z0-9._%-]+@[a-zA-Z0-9._%-]+.[a-zA-Z]{2,6}$')

def ipthrottle(limit=IP_LIMIT, time=IP_THROTTLE_TIME, keySuffix=None):
  """Decorate with this method to throttle request per ip."""
  def _ipthrottle(method):
    @functools.wraps(method)
    def wrapper(self, *args, **kwargs):
      name = method.__name__
      ip = self.request.remote_addr
      if keySuffix:
        NS = "%s|%s"%(IP_THROTTLE_NS, keySuffix)
      else:
        NS = IP_THROTTLE_NS
      key = "%s:%s"%(name,ip)
      hits = memcache.get(key, namespace=NS)
      if not hits:
        hits = 1
        memcache.set(key, hits, namespace=NS, time=time)
      else:
        if hits >= limit:
          #TODO: send email about absusive IP
          logging.debug("IP THROTTLED: %s"%(ip,))
          return
        else:
          memcache.incr(key, namespace=NS)
      return method(self, *args, **kwargs)
    return wrapper
  return _ipthrottle

def administrator(method):
  """Decorate with this method to restrict to site admins."""
  @functools.wraps(method)
  def wrapper(self, *args, **kwargs):
    user = users.get_current_user()
    if not user:
      if self.request.method == "GET":
        self.redirect(users.create_login_url())
        return
      raise self.response.set_status(403)
    elif not users.is_current_user_admin():
      if self.request.method == "GET":
        self.redirect("/")
        return
      raise self.response.set_status(403)
    else:
      return method(self, *args, **kwargs)
  return wrapper

def jsonp(method):
  @functools.wraps(method)
  def wrapper(self, *args, **kwargs):
    callback = self.request.get('callback')
    if callback:
      self.response.out.write('%s('%(callback,))
      method(self, *args, **kwargs)
      self.response.out.write(');')
      self.response.headers['Content-Type'] = 'text/javascript'
    else:
      method(self, *args, **kwargs)

def valid_email(email):
  return EMAIL_RE.match(email) is not None

SIMPLE_TYPES = (int, long, float, bool, dict, basestring, list)

def to_dict(model,only=None,exclude=list(),with_id=True):
  output = {}
  iterator = only
  if iterator is None or not isinstance(iterator, list):
    iterator = model.properties().iterkeys()
  for key in iterator:
    if key in exclude:
      continue
    value = getattr(model, key)
    if value is None or isinstance(value, SIMPLE_TYPES):
      output[key] = value
    elif isinstance(value, datetime.date):
      # Convert date/datetime to ms-since-epoch ("new Date()").
      ms = time.mktime(value.utctimetuple()) * 1000
      ms += getattr(value, 'microseconds', 0) / 1000
      output[key] = int(ms)
    elif isinstance(value, db.GeoPt):
        output[key] = {'lat': value.lat, 'lon': value.lon}
    elif isinstance(value, blobstore.BlobInfo):
      output[key] = to_dict(str(value))
    elif isinstance(value, db.Model):
      output[key] = to_dict(value)
    else:
      raise ValueError('cannot encode ' + repr(value))
    if with_id:
      output["id"] = model.key().id()
  return output