Source code for oauth_dropins.webutil.instance_info

"""Renders vital stats about a single App Engine instance.

Intended for developers, not users. To turn on concurrent request recording, add the middleware and InfoHandler to your WSGI application, eg:

  from oauth_dropins.webutil.instance_info import concurrent_requests_wsgi_middleware, InfoHandler

  application = concurrent_requests_wsgi_middleware(webapp2.WSGIApplication([
      ('/_info', InfoHandler),
import collections
import datetime
import heapq
import os
import threading

from . import handlers


# A time when there was more than one request running at once. count is the
# first field so that instances compare by count, since they're stored in a
# heap, so that we keep the highest count instances.
Concurrent = collections.namedtuple('Concurrent', ('count', 'when'))

# globals
current_requests = set()  # stores string request IDs
current_requests_lock = threading.Lock()
concurrents = []  # a heapq. stores Concurrents

[docs]class InfoHandler(handlers.TemplateHandler):
[docs] def template_file(self): return os.path.join(os.path.dirname(__file__), 'templates/instance_info.html')
[docs] def template_vars(self): return {'concurrents': concurrents, 'current_requests': current_requests, 'os': os, 'runtime': os.getenv('GAE_RUNTIME'), }
[docs]def concurrent_requests_wsgi_middleware(app): """WSGI middleware for per request instance info instrumentation. Follows the WSGI standard. Details: """ def wrapper(environ, start_response): req_id = os.environ['REQUEST_LOG_ID'] global current_requests, current_requests_lock, concurrents with current_requests_lock: current_requests.add(req_id) if len(current_requests) > 1: heapq.heappush(concurrents, Concurrent(count=len(current_requests), if len(concurrents) > CONCURRENTS_SIZE: heapq.heappop(concurrents) ret = app(environ, start_response) with current_requests_lock: current_requests.remove(req_id) return ret return wrapper