Our lib `clj-rq` now generates itself dynamically

A month ago, we published in our blog the thrilling first stable release of our library clj-rq. You can read more of this post here.

For the newcomers, clj-rq is a homebrewed library that wraps Jedis, being itself a simple Redis library for the Clojure ecosystem.

About developing a wrapper library

One of the first comments that got between ourselves, the moclojer team was how it would be complicated to update every helper function as the jedis/redis command interfaces changed throughout the years. Besides that, other important topics that got under our radar, in no specific order, were also:

• Better compatibility with existing standards;
• Ease of iteration;
• Lower the possibility of human error;
• Not overcomplicate/reinvent the wheel;

Under the hood

This inspired us to remodel clj-rq to dynamically generate itself, using this simplified procedure:

1. By using reflection, load the predefined methods from the Jedis library;
2. Parse these raw methods into a usable data structure;
3. Build through a macro a function that calls the Jedis equivalent one;
4. Wrap these functions into a clojure idiomatic equivalent, like how lpush becomes push! with the direction configurable through options;

Installation

We distribute the library via Clojars.

deps.edn:

1

com.moclojer/rq {:mvn/version "0.2.1"}

project.clj:

1

[com.moclojer/rq "0.2.1"]

Be sure to check the latest versions incase you’re reading this in the future.

Showcase

The “source code voyagers” will be pleased to see how this was implemented here.

For those who lack time, here follows a simple showcase of clj-rq. Virtually, the lib didn’t change. the way it builds and works under the hood did.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33

(ns rq.example
  (:require [com.moclojer.rq :as rq]
            [com.moclojer.rq.queue :as queue]
            [com.moclojer.rq.pubsub :as pubsub]))

(def *redis-pool* (rq/create-client "redis://localhost:6379/0"))

;; queue
(queue/push! *redis-pool* "my-queue"
             ;; has to be an array of the elements to push
             [{:now (java.time.LocalDateTime/now)
              :foo "bar"}])

(println :size (queue/len *redis-pool* "my-queue"))
(prn :popped (queue/pop! *redis-pool* "my-queue"))

;; pub/sub
(def my-workers
  [{:channel "my-channel"
    :handler (fn [msg]
               (prn :msg :my-channel msg))}
   {:channel "my-other-channel"
    :handler (fn [{:keys [my data hello]}]
               (my-function my data hello))}])

(pubsub/subscribe! *redis-pool* my-workers)
(pubsub/publish! *redis-pool* "my-channel" "hello world")
(pubsub/publish! *redis-pool* "my-other-channel"
                 {:my "moclojer team"
                 :data "app.moclojer.com"
                 :hello "maybe you'll like this website"})

(rq/close-client *redis-pool*)

For a more extensive documentation of the supported commands, give a look at our readme.

It is important to remember that this change doesn’t invalidate the work of our open source engineers. There was a lot of thought and time spent to make sure our lib is delivered top-notch and ready for production. It is, nonetheless, easier to maintain now 😃.

Using stuartsierra’s component lib

If you use stuartsierra’s component lib, we’ve also recently released our components bundle version v0.1.0. It wraps clj-rq and presents you with a seamless and simple integration.

Installation

We distribute components via Clojars.

deps.edn:

1

com.moclojer/components {:mvn/version "0.1.1"}

project.clj:

1

[com.moclojer/components "0.1.1"]

Be sure to check the latest versions incase you’re reading this in the future.

Thanks for reading. You can find more about moclojer, who we are, what we do, what we eat and more at our home page, our github, and maybe our product.