Add CNS function to clean up port matching requester IP address.

media/tools/constrained_network_server/cns.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Constrained Network Server. Serves files with supplied network constraints.
 
 The CNS exposes a web based API allowing network constraints to be imposed on
 file serving.
 
@@ skipping 114 matching lines @@
     """
     kwargs['port'] = port
     try:
       cherrypy.log('Setting up port %d' % port)
       traffic_control.CreateConstrainedPort(kwargs)
       return True
     except traffic_control.TrafficControlError as e:
       cherrypy.log('Error: %s\nOutput: %s' % (e.msg, e.error))
       return False
 
-  def Cleanup(self, all_ports):
+  def Cleanup(self, all_ports, request_ip=None):
     """Cleans up expired ports, or if all_ports=True, all allocated ports.
 
     By default, ports which haven't been used for self._expiry_time_secs are
     torn down. If all_ports=True then they are torn down regardless.
 
     Args:
       all_ports: Should all ports be torn down regardless of expiration?
+      request_ip: Tear ports matching the IP address regarless of expiration.
     """
     with self._port_lock:
       now = time.time()
       # Use .items() instead of .iteritems() so we can delete keys w/o error.
       for port, status in self._ports.items():
         expired = now - status['last_update'] > self._expiry_time_secs
-        if all_ports or expired:
+        matching_ip = request_ip and status['key'][0].startswith(request_ip)
+        if all_ports or expired or matching_ip:
           cherrypy.log('Cleaning up port %d' % port)
           self._DeletePort(port)
           del self._ports[port]
 
   def _DeletePort(self, port):
     """Deletes network constraints on port.
 
     Args:
       port: The port number associated with the network constraints.
     """
@@ skipping 10 matching lines @@
     """Sets up initial state for the CNS.
 
     Args:
       options: optparse based class returned by ParseArgs()
       port_allocator: A port allocator instance.
     """
     self._options = options
     self._port_allocator = port_allocator
 
   @cherrypy.expose
+  def Cleanup(self):
+    """Cleans up all the ports allocated using the request IP address.
+
+    When requesting a constrained port, the cherrypy.request.remote.ip is used
+    as a key for that port (in addition to other request parameters).  Such
+    ports created for the same IP address are removed.
+    """
+    cherrypy.log('Cleaning up ports allocated by %s.' %
+                 cherrypy.request.remote.ip)
+    self._port_allocator.Cleanup(all_ports=False,
+                                 request_ip=cherrypy.request.remote.ip)
+
+  @cherrypy.expose
   def ServeConstrained(self, f=None, bandwidth=None, latency=None, loss=None,
                        new_port=False, no_cache=False, **kwargs):
     """Serves the requested file with the requested constraints.
 
     Subsequent requests for the same constraints from the same IP will share the
     previously created port unless new_port equals True. If no constraints
     are provided the file is served as is.
 
     Args:
       f: path relative to http root of file to serve.
@@ skipping 243 matching lines @@
   try:
     cherrypy.quickstart(ConstrainedNetworkServer(options, pa))
   finally:
     # Disable Ctrl-C handler to prevent interruption of cleanup.
     signal.signal(signal.SIGINT, lambda signal, frame: None)
     pa.Cleanup(all_ports=True)
 
 
 if __name__ == '__main__':
   Main()