"""oohEmbed
Your one-stop oEmbed provider
See http://code.google.com/p/oohembed/
and http://oohembed.com/
Copyright (c) 2008-2009, Deepak Sarda
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following
disclaimer in the documentation and/or other materials provided
with the distribution.
* Neither the name of the oohEmbed project nor the names of its
contributors may be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
"""
import wsgiref.handlers
import datetime
import logging
import os
import urllib
import email.utils
import time
from google.appengine.ext import webapp
from google.appengine.api import memcache
from jinja import Environment, FileSystemLoader
from provider import *
HTTP_DATE_FMT = "%a, %d %b %Y %H:%M:%S GMT"
CACHE_SEP = "=+=+="
CACHE_TIME = 2*24*60*60
class EndPoint(webapp.RequestHandler):
providers = Provider.get_providers()
def get(self):
query_url = urllib.unquote(self.request.get('url').encode('utf-8')).strip().rstrip("#")
resp_format = self.request.get('format', default_value='json')
logging.debug('Incoming request for %s' % query_url)
if 'Development' in os.environ['SERVER_SOFTWARE']:
self.response.headers['Content-Type'] = 'text/plain; charset=utf-8'
else:
self.response.headers['Content-Type'] = 'application/json'
if not query_url:
self.error(400)
self.response.out.write('Missing url parameter in request')
return
if not resp_format in ['json', 'jsonp']:
self.error(501)
self.response.out.write('Only json format is currently supported')
return
callback = self.request.get('callback').encode('utf-8')
# TODO: Make sure callback name here is a valid Javascript
# variable name using a whitelist. Otherwise raise 400
extra_params = {}
if self.request.get('maxwidth'):
extra_params['maxwidth'] = self.request.get('maxwidth').encode('utf-8')
if self.request.get('maxheight'):
extra_params['maxheight'] = self.request.get('maxheight').encode('utf-8')
# Check memcache
cached_item = memcache.get(make_key(query_url, extra_params))
if cached_item:
logging.debug('Cache hit for url %s' % query_url)
resp, timestamp = cached_item.split(CACHE_SEP)
self.send_response(resp, last_modified=timestamp, callback=callback)
return
resp = None
for p in self.providers:
try:
resp = p.provide(query_url, extra_params)
if resp:
# Save to memcache first
timestamp = datetime.datetime.now().strftime(HTTP_DATE_FMT)
if not memcache.set(make_key(query_url, extra_params), resp + CACHE_SEP + timestamp, time=CACHE_TIME):
logging.error('Failed saving cache for url %s' % query_url)
else:
logging.debug('Saved url response to cache for url %s' % query_url)
self.send_response(resp, last_modified=timestamp, callback=callback)
return
except UnsupportedUrlError, e:
pass
except HTTPError, e:
self.error(e.code)
if e.content:
self.response.out.write(e.content)
else:
self.response.out.write("Encountered HTTP Error %s fetching " +
"url from the remote host" % e.code)
return
except OohEmbedError, e:
logging.error("Throwing OohEmbed error", exc_info=True)
self.error(500)
return self.response.out.write(e.reason)
except Exception, e:
logging.error("Throwing 500 error", exc_info=True)
self.error(500)
return self.response.out.write("Unrecoverable error. Please try again." +
" If the error persists, please file a bug at http://oohembed.googlecode.com/")
self.error(404)
self.response.out.write('Could not determine suitable ' +
'representation for queried URL')
return
def send_response(self, resp, last_modified=None, callback=None):
if 'Development' not in os.environ['SERVER_SOFTWARE']:
self.response.headers['Expires'] = email.utils.formatdate(time.time() + CACHE_TIME, usegmt=True)
self.response.headers['Cache-Control'] = 'max-age=%d' % int(CACHE_TIME)
if last_modified:
if last_modified == self.request.headers.get('If-Modified-Since', '-1'):
self.error(304)
return
else:
self.response.headers['Last-Modified'] = last_modified.encode('utf-8')
if callback:
self.response.headers['Content-Type'] = 'text/javascript'
resp = '%s(%s);' % (callback, resp)
self.response.out.write(resp)
class AdminEndPoint(webapp.RequestHandler):
def get(self):
if self.request.get('flushcache'):
result = memcache.flush_all()
response = 'memcache flush ' + (result and 'succeeded' or 'failed')
return self.response.out.write(response)
elif self.request.get('infocache'):
result = memcache.get_stats()
if result:
body = '
'.join(('%s: %s\n' % t for t in result.iteritems()))
else:
body = 'failed to retrieve memcache stats'
response = 'Memcache Stats' + body
return self.response.out.write(response)
else:
return self.response.out.write('What function did you want? "infocache" or "flushcache"?')
class MainPage(webapp.RequestHandler):
providers = Provider.get_providers()
def get(self):
providers = [{'title': p.title, 'url': p.url, \
'example_url': p.example_url, \
'description': p.__doc__} \
for p in self.providers]
providers.sort(lambda x, y: cmp(x['title'].lower(), y['title'].lower()))
if 'Development' in os.environ['SERVER_SOFTWARE']:
production = False
else:
production = True
env = Environment(loader=FileSystemLoader(os.path.dirname(__file__)))
tmpl = env.get_template('index.jinja')
hostname = os.environ['HTTP_HOST'].lower()
self.response.out.write(tmpl.render(providers=providers,
production=production, hostname=hostname))
urls = [('/', MainPage),
('/oohembed\/?', EndPoint),
('/admin/', AdminEndPoint)
]
def main():
if 'Development' in os.environ['SERVER_SOFTWARE']:
logging.getLogger().setLevel(logging.DEBUG)
else:
logging.getLogger().setLevel(logging.INFO)
application = webapp.WSGIApplication(urls, debug=True)
wsgiref.handlers.CGIHandler().run(application)
if __name__ == "__main__":
main()