async-test

async-test.clj

(ns async-example
  (:require [clojure.core.async :as a :refer [>! <! >!! <!! go chan buffer close! thread alts! alts!! put! timeout sliding-buffer]]
            [clj-http.client :as client]
            [cheshire.core :refer :all]))

(defn sample-request-async [x y c]
  (let [response-cb (fn [response]
                      (go (>! c response)))
        exception-cb (fn [^Throwable exception]
                       (println exception))]
    (client/post
      "http://localhost:3000/add"
      {:form-params        {:x x
                            :y y}
       :async?             true
       :connection-timeout 2000}
      response-cb
      exception-cb)
    c))

(defn sample-request [x y]
  (client/post
    "http://localhost:3000/add"
    {:form-params {:x x
                   :y y}}))

(defn sample-request-mock [x y]
  (Thread/sleep 1000)
  (+ x y))

(comment
  (doseq [_ (range 2)]
    (prn (sample-request-mock (rand-int 100) (rand-int 100))))

  ;; use buffer
  (time
    (let [cs (chan 9999)]
      (->> (for [x (range 9999)]
             (do
               (prn "Active thread =>" (Thread/activeCount))
               (go (>! cs (sample-request-mock (rand-int 100) (rand-int 100))))))
           (map (fn [_] (<!! cs)))
           count)))

  ;; thread can use more threads than go-block
  ;; suitable for doing long blocking IOs
  (time
    (let [cs (chan 9999)]
      (->> (for [x (range 9999)]
             (do
               (prn "Active thread =>" (Thread/activeCount))
               (thread (>!! cs (sample-request-mock (rand-int 100) (rand-int 100))))))
           (map (fn [_] (<!! cs)))
           count))),)