Tests JSON encoding performance of different clojure libs

output.txt

content length
5073891
cheshire
"Elapsed time: 103.332902 msecs"
clj-json
"Elapsed time: 79.033905 msecs"
core.json
"Elapsed time: 638.59961 msecs"

write-json-speed.clj

(use '[leiningen.exec :only (deps)])
(deps '[[cheshire "5.5.0"]
        [clj-json "0.5.3"]
        [org.clojure/data.json "0.2.6"]])

(ns json-speed-test
  (:require [clojure.data.json :as core]
            [cheshire.core :as cheshire]
            [clj-json [core :as cljjson]]))

(defn rand-string
  [& args]
  (->> (range (or (first args)
                  (rand-int 50)))
       (map (fn [x] (+ 65 (rand-int 26))))
       (map #(char %))
       (map #(Character/toString %))
       (apply str)))

(let [payload  (->> (range 15000)
                    (map #(assoc {} :id (str "app-" %)
                                    :name (rand-string 20)
                                    :team-id (rand-string 10)
                                    :description (rand-string 250)))
                    (doall))]
    (println "content length")
    (println (count (cljjson/generate-string payload)))
    (println "cheshire")
    (time (cheshire/generate-string payload))
    (println "clj-json")
    (time (cljjson/generate-string payload))
    (println "core.json")
    (time (core/write-str payload)))