code/breadcrumb/server/handlers/http.py

   1 # -*- coding: utf8 -*-
   2 """ HTTP handler code for Breadcrumb servers. """
   3
   4 # Copyright (C) 2008 Laurens Van Houtven <lvh at laurensvh.be>
   5 # This program is free software: you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation, either version 3 of the License, or
   8 # (at your option) any later version.
   9 #
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License
  16 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 import urllib
  19 import httplib
  20 import logging
  21 import time
  22
  23 from common import PointQueueHandler, Renderer
  24
  25 class HTTPHandler(PointQueueHandler, Renderer):
  26     """A handler for sending data over HTTP.
  27
  28     ``action`` and ``name`` mean the same thing as in an HTML form. This is
  29     illustrated by the following example:
  30
  31     To POST something to a server for which the URL looks like this::
  32
  33         http://test.example:8080/my_cgi_app
  34
  35     ... and the element looks something like this::
  36
  37         <input name="foo" action="/my_cgi_app" method='POST' />
  38
  39     you would create a handler instance like this::
  40
  41         HTTPHandler(host = "text.example",
  42                     port = 8080,
  43                     action = "/my_cgi_app",
  44                     name = "foo")
  45
  46     We don't need to pass the method here, because POST is the default. You can
  47     use any string httplib understands (``GET``, for example.).
  48
  49     This handler opens a new HTTP connection for each submission.
  50     """
  51     def __init__(self,
  52                  host = "localhost", port = 80,
  53                  action = None, name = None, method = 'POST',
  54                  burst_length = 1,
  55                  rendertype = None):
  56         PointQueueHandler.__init__(self,
  57                                    burst_length = burst_length,
  58                                    identifiers = ('\x30', '\x31'))
  59         Renderer.__init__(self, type = rendertype)
  60
  61         if not all([action, name, method]):
  62             raise RuntimeError, 'not enough parameters for HTTPHandler'
  63         else:
  64             self.action, self.element, self.method = action, name, method
  65
  66         self.host, self.port = str(host), int(port)
  67         self.headers = {}
  68
  69         for identifier in ['\x30, \x31']:
  70             self.identifiers.add(identifier)
  71
  72         logging.debug("Initialized HTTPHandler at %s:%s" % (host, port))
  73
  74     def send(self, outstr):
  75         """Sends the given string across HTTP."""
  76         parameters = urllib.urlencode({self.element: outstr})
  77
  78         connection = httplib.HTTPConnection("%s:%d" % (self.host, self.port))
  79         connection.request(self.method, self.action, parameters, self.headers)
  80         connection.close()