ezeque

A lazy promise of events in the future

This is just an experiment with zeromq and processing events via lazy-seqs.

prerequisites

• You'll need zeromq 3.2 installed on your machine.

• on linux if libzmq isnt in /usr/local/lib then set jna.library.path to where libzmq is installed (see project.clj)

• (for now) on windows I renamed libzmq-v100-mt.dll to zmq.dll and set jna.library.path=C:\Program Files\ZeroMQ-3.2.0\bin

example

Note that Im just using simple pubsub in zmq so this is prone to the slow-subscriber problem described in the zguide.

git clone https://github.com/bartonj/ezeque.git
cd ezeque
lein repl
;; start pubsub on port 5555
ezeque.core=> (start)
...

;; test it works
ezeque.core=> (raise :blabla)
...

;; start an event consumer that filters on even :myval
ezeque.core=> (future (doseq [e (filter #(even? (:myval %)) (instream))]
                    (println "myfilter" (pr-str e))) 
               (println "myfilter done"))
...

;; raise a whole lot of events to see consumer react
ezeque.core=> (doseq [i (range 500)] (raise {:myevent :bla :myval i}))
...

;; you can start another repl subscribe to port 5555
;; for the same events as above but a different filter
lein repl
ezeque.core=> (future (doseq [e (filter #(odd? (:myval %)) (instream))]
                    (println "myfilter" (pr-str e))) 
               (println "myfilter done"))
ezeque.core=> (start nil ["tcp://localhost:5555"])
...
;; run the raise doseq again on the first repl

licences

This is my understanding of the licences:

• ezeque © 2012 Justin Barton - epl 1.0 (same as clojure)
• zeromq © 2007-2011 iMatix - lgpl 3.0
• jna © 2011 Timothy Wall - lgpl 2.1+