Synnefo » Pithos

# Copyright 2012 GRNET S.A. All rights reserved.

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import pika

import json

from urlparse import urlparse

def exchange_connect(exchange, vhost='/'):

    """Format exchange as a URI: rabbitmq://user:pass@host:port/exchange"""

    parts = urlparse(exchange)

    if parts.scheme != 'rabbitmq':

        return None

    if len(parts.path) < 2 or not parts.path.startswith('/'):

        return None

    exchange = parts.path[1:]

    connection = pika.BlockingConnection(pika.ConnectionParameters(

                    host=parts.hostname, port=parts.port, virtual_host=vhost,

                    credentials=pika.PlainCredentials(parts.username, parts.password)))

    channel = connection.channel()

    channel.exchange_declare(exchange=exchange, type='topic', durable=True)

    return (connection, channel, exchange)

def exchange_close(conn):

    connection, channel, exchange = conn

    connection.close()

def exchange_send(conn, key, value):

    """Messages are sent to exchanges at a key."""

    connection, channel, exchange = conn

    channel.basic_publish(exchange=exchange,

                          routing_key=key,

                          body=json.dumps(value))

def exchange_route(conn, key, queue):

    """Set up routing of keys to queue."""

    connection, channel, exchange = conn

    channel.queue_declare(queue=queue, durable=True,

                          exclusive=False, auto_delete=False)

    channel.queue_bind(exchange=exchange,

                       queue=queue,

                       routing_key=key)

def queue_callback(conn, queue, cb):

    def handle_delivery(channel, method_frame, header_frame, body):

        #print 'Basic.Deliver %s delivery-tag %i: %s' % (header_frame.content_type,

        #                                                method_frame.delivery_tag,

        #                                                body)

        if cb:

            cb(json.loads(body))

        channel.basic_ack(delivery_tag=method_frame.delivery_tag)

    connection, channel, exchange = conn

    channel.basic_consume(handle_delivery, queue=queue)

def queue_start(conn):

    connection, channel, exchange = conn

    channel.start_consuming()