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Pub/Sub pattern with PostgreSQL's LISTEN/NOTIFY command

This is a simple chat-like program using pub-sub pattern, backed by PostgreSQL's LISTEN/NOTIFY command.

Publish

publish message to foo channel from user nickname.

$ python pub.py foo nickname
PUBLISH to channel #foo

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# RESOURCE
- WAIT4(2)
http://www.kernel.org/doc/man-pages/online/pages/man2/wait4.2.html
- GETRUSAGE(2) 
http://www.kernel.org/doc/man-pages/online/pages/man2/getrusage.2.html
- The Linux Programming Interface
§26.1.6 The wait3() and wait4() System Calls
- Python Documentation
http://docs.python.org/2/library/os.html
http://docs.python.org/2/library/resource.html

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# chat server using multicast
# python fork of the original ruby implementation
# http://tx.pignata.com/2012/11/multicast-in-ruby-building-a-peer-to-peer-chat-system.html
# receiver.py
# usage : $ python receiver.py  # wait for messages to come in

import socket
import struct

multicast_addr = '224.0.0.1'

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$ python us_xfr_sv.py > b &
[1] 1553
$ cat *py > a
$ python us_xfr_cl.py  < a
$ kill %1
[1]+  Terminated              python us_xfr_sv.py > b
$ diff -u a b
$

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# The Linux Programming Interface Listing 57-6
$ python ud_ucase_sv.py &
[1] 437
$ python ud_ucase_cl.py  hello world
Server received 5 bytes from /tmp/ud_ucase.452
Response 1 : HELLO
Server received 5 bytes from /tmp/ud_ucase.452
Response 2 : WORLD
$ python ud_ucase_cl.py  'long message'
Server received 10 bytes from /tmp/ud_ucase.763

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# http://basho.com/blog/technical/2012/10/16/Basho-Package-Repos-Now-Online/
$ curl http://apt.basho.com/gpg/basho.apt.key | sudo apt-key add -
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  1016  100  1016    0     0   1407      0 --:--:-- --:--:-- --:--:--  4861
OK
$ sudo bash -c "echo deb http://apt.basho.com `lsb_release -sc` main > /etc/apt/sources.list.d/basho.list"
$ sudo apt-get update
...
Ign http://apt.basho.com precise/main Translation-en_US

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from pika.adapters import BlockingConnection

connection = BlockingConnection()
channel = connection.channel()

def callback(ch, method, properties, body):
    print " [x] Received %r" % (body,)

channel.basic_consume(callback,
                      queue='test_queue',

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# zabbix_get.py : Python port of zabbix_get
# http://www.zabbix.com/documentation/1.8/protocols/agent
# http://www.zabbix.com/wiki/doc/tech/proto/zabbixagentprotocol

import argparse
import socket
import struct
import sys

def str2packed(data):

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#!/usr/bin/env python
# http://www.rabbitmq.com/tutorials/tutorial-two-python.html
import pika
import sys

connection = pika.BlockingConnection(pika.ConnectionParameters(
        host='localhost'))
channel = connection.channel()

message = ' '.join(sys.argv[1:]) or "Hello World!"

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# http://en.wikipedia.org/wiki/Bloom_filter#Counting_filters
# http://www.michaelnielsen.org/ddi/why-bloom-filters-work-the-way-they-do/
import hashlib

class BloomFilter(object):

    def __init__(self, m, k):
        self.m = m
        self.k = k
        self.array = [0 for i in range(m)]