code.grnet.gr Git - pithos/blob - snf-pithos-lib/pithos/lib/queue.py

   1 # Copyright 2012 GRNET S.A. All rights reserved.
   2 #
   3 # Redistribution and use in source and binary forms, with or
   4 # without modification, are permitted provided that the following
   5 # conditions are met:
   6 #
   7 #   1. Redistributions of source code must retain the above
   8 #      copyright notice, this list of conditions and the following
   9 #      disclaimer.
  10 #
  11 #   2. Redistributions in binary form must reproduce the above
  12 #      copyright notice, this list of conditions and the following
  13 #      disclaimer in the documentation and/or other materials
  14 #      provided with the distribution.
  15 #
  16 # THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
  17 # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  18 # WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  19 # PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
  20 # CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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  24 # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  26 # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  27 # POSSIBILITY OF SUCH DAMAGE.
  28 #
  29 # The views and conclusions contained in the software and
  30 # documentation are those of the authors and should not be
  31 # interpreted as representing official policies, either expressed
  32 # or implied, of GRNET S.A.
  33
  34 import pika
  35 import json
  36 import uuid
  37
  38 from urlparse import urlparse
  39 from hashlib import sha1
  40 from random import random
  41 from time import time
  42
  43
  44 def exchange_connect(exchange, vhost='/'):
  45     """Format exchange as a URI: rabbitmq://user:pass@host:port/exchange"""
  46     parts = urlparse(exchange)
  47     if parts.scheme != 'rabbitmq':
  48         return None
  49     if len(parts.path) < 2 or not parts.path.startswith('/'):
  50         return None
  51     exchange = parts.path[1:]
  52     connection = pika.BlockingConnection(pika.ConnectionParameters(
  53                     host=parts.hostname, port=parts.port, virtual_host=vhost,
  54                     credentials=pika.PlainCredentials(parts.username, parts.password)))
  55     channel = connection.channel()
  56     channel.exchange_declare(exchange=exchange, type='topic', durable=True)
  57     return (connection, channel, exchange)
  58
  59 def exchange_close(conn):
  60     connection, channel, exchange = conn
  61     connection.close()
  62
  63 def exchange_send(conn, key, value):
  64     """Messages are sent to exchanges at a key."""
  65     connection, channel, exchange = conn
  66     channel.basic_publish(exchange=exchange,
  67                           routing_key=key,
  68                           body=json.dumps(value))
  69
  70
  71 def exchange_route(conn, key, queue):
  72     """Set up routing of keys to queue."""
  73     connection, channel, exchange = conn
  74     channel.queue_declare(queue=queue, durable=True,
  75                           exclusive=False, auto_delete=False)
  76     channel.queue_bind(exchange=exchange,
  77                        queue=queue,
  78                        routing_key=key)
  79
  80 def queue_callback(conn, queue, cb):
  81
  82     def handle_delivery(channel, method_frame, header_frame, body):
  83         #print 'Basic.Deliver %s delivery-tag %i: %s' % (header_frame.content_type,
  84         #                                                method_frame.delivery_tag,
  85         #                                                body)
  86         if cb:
  87             cb(json.loads(body))
  88         channel.basic_ack(delivery_tag=method_frame.delivery_tag)
  89
  90     connection, channel, exchange = conn
  91     channel.basic_consume(handle_delivery, queue=queue)
  92
  93 def queue_start(conn):
  94     connection, channel, exchange = conn
  95     channel.start_consuming()
  96
  97 class Receipt(object):
  98     def __init__(self, client, user, resource, value, details={}):
  99         self.eventVersion = '1.0'
 100         self.occurredMillis = int(time() * 1000)
 101         self.receivedMillis = self.occurredMillis
 102         self.clientID = client
 103         self.userID = user
 104         self.resource = resource
 105         self.value = value
 106         self.details = details
 107         hash = sha1()
 108         hash.update(json.dumps([client, user, resource, value, details, random()]))
 109         self.id = hash.hexdigest()
 110
 111     def format(self):
 112         return self.__dict__