jsonista

jsonissa / jsonista / jsoniin, jsonilla / jsonilta / jsonille

Clojure library for fast JSON encoding and decoding.

• Explicit configuration
• Uses jackson-databind
• Mostly written in Java for speed
• API docs
• FAQ

Faster than data.json or Cheshire while still having the necessary features for web development. Designed for use with Muuntaja.

Blogged:

• Faster JSON processing with jsonista

Latest version

Requires Java1.8+

Quickstart

(require '[jsonista.core :as j])

(j/write-value-as-string {"hello" 1})
;; => "{\"hello\":1}"

(j/read-value *1)
;; => {"hello" 1}

Examples

Using explicit ObjectMapper:

(-> {:dog {:name "Teppo"}}
    (j/write-value-as-bytes j/default-object-mapper)
    (j/read-value j/default-object-mapper))
;; => {"dog" {"name" "Teppo"}}

Using keyword keys:

(-> {:dog {:name "Teppo"}}
    (j/write-value-as-bytes j/keyword-keys-object-mapper)
    (j/read-value j/keyword-keys-object-mapper))
;; => {:dog {:name "Teppo"}}

Changing how map keys are encoded & decoded:

(defn reverse-string [s] (apply str (reverse s)))

(def mapper
  (j/object-mapper
    {:encode-key-fn (comp reverse-string name)
     :decode-key-fn (comp keyword reverse-string)}))

(-> {:kikka "kukka"}
    (doto prn)
    (j/write-value-as-string mapper)
    (doto prn)
    (j/read-value mapper)
    (prn))
; {:kikka "kukka"}
; "{\"akkik\":\"kukka\"}"
; {:kikka "kukka"}

Reading & writing directly into a file:

(def file (java.io.File. "hello.json"))

(j/write-value file {"hello" "world"})

(slurp file)
;; => "{\"hello\":\"world\"}"

(j/read-value file)
;; => {"hello" "world"}

Adding support for joda-time Classes, used by clj-time.

;; [com.fasterxml.jackson.datatype/jackson-datatype-joda "2.9.5"]
(import '[com.fasterxml.jackson.datatype.joda JodaModule])
(import '[org.joda.time LocalDate])

(def mapper
  (j/object-mapper
    {:modules [(JodaModule.)]}))

(j/write-value-as-string (LocalDate. 0) mapper)
; "\"1970-01-01\""

Tagged JSON

Adding support for lossless encoding data using tagged values. This includes both reading and writing support.

(def mapper
  (j/object-mapper
    {:encode-key-fn true
     :decode-key-fn true
     :modules [(jt/module
                 {:handlers {Keyword {:tag "!kw"
                                      :encode jt/encode-keyword
                                      :decode keyword}
                             PersistentHashSet {:tag "!set"
                                                :encode jt/encode-collection
                                                :decode set}}})]}))

(-> {:system/status #{:status/good}}
    (j/write-value-as-string mapper)
    (doto prn)
    (j/read-value mapper))
; prints "{\"system/status\":[\"!set\",[[\"!kw\",\"status/good\"]]]}"
; => {:system/status #{:status/good}}

In simple perf tests, tagged JSON is much faster than EDN or Transit.

Performance

• All standard encoders and decoders are written in Java
• Protocol dispatch with read-value & write-value
• Jackson ObjectMapper is used directly
• Small functions to support JVM Inlining

Measured using lein-jmh, see perf-tests for details.

Throughput, relative

Throughput, absolute

Throughput, data

➜  jsonista git:(master) ✗ lein jmh '{:file "benchmarks.edn", :type :quick, :format :table}'
{:% 100.0 :eta "00:00:00"}

:benchmark                     :name    :mode        :samples  :score              :score-error  :params
-----------------------------  -------  -----------  --------  ------------------  ------------  --------------
jsonista.jmh/encode-data-json  :encode  :throughput  5         2005040.000  ops/s  18641.040     {:size "10b"}
jsonista.jmh/encode-data-json  :encode  :throughput  5         332469.712   ops/s  58885.657     {:size "100b"}
jsonista.jmh/encode-data-json  :encode  :throughput  5         60609.008    ops/s  11476.851     {:size "1k"}
jsonista.jmh/encode-data-json  :encode  :throughput  5         4970.188     ops/s  638.168       {:size "10k"}
jsonista.jmh/encode-data-json  :encode  :throughput  5         581.102      ops/s  5.168         {:size "100k"}
jsonista.jmh/encode-cheshire   :encode  :throughput  5         1205106.095  ops/s  42282.531     {:size "10b"}
jsonista.jmh/encode-cheshire   :encode  :throughput  5         450330.840   ops/s  23666.810     {:size "100b"}
jsonista.jmh/encode-cheshire   :encode  :throughput  5         105423.654   ops/s  8408.732      {:size "1k"}
jsonista.jmh/encode-cheshire   :encode  :throughput  5         9734.970     ops/s  118.249       {:size "10k"}
jsonista.jmh/encode-cheshire   :encode  :throughput  5         978.945      ops/s  8.672         {:size "100k"}
jsonista.jmh/encode-jsonista   :encode  :throughput  5         6761392.263  ops/s  113396.242    {:size "10b"}
jsonista.jmh/encode-jsonista   :encode  :throughput  5         1976136.012  ops/s  50656.525     {:size "100b"}
jsonista.jmh/encode-jsonista   :encode  :throughput  5         393627.163   ops/s  4972.565      {:size "1k"}
jsonista.jmh/encode-jsonista   :encode  :throughput  5         31114.706    ops/s  557.984       {:size "10k"}
jsonista.jmh/encode-jsonista   :encode  :throughput  5         2887.899     ops/s  59.618        {:size "100k"}
jsonista.jmh/encode-jackson    :encode  :throughput  5         6108654.930  ops/s  2090135.205   {:size "10b"}
jsonista.jmh/encode-jackson    :encode  :throughput  5         1944127.861  ops/s  431031.615    {:size "100b"}
jsonista.jmh/encode-jackson    :encode  :throughput  5         356943.193   ops/s  3977.765      {:size "1k"}
jsonista.jmh/encode-jackson    :encode  :throughput  5         31697.766    ops/s  1753.636      {:size "10k"}
jsonista.jmh/encode-jackson    :encode  :throughput  5         2562.607     ops/s  177.252       {:size "100k"}
jsonista.jmh/decode-data-json  :decode  :throughput  5         2208464.243  ops/s  187701.406    {:size "10b"}
jsonista.jmh/decode-data-json  :decode  :throughput  5         524637.916   ops/s  28974.507     {:size "100b"}
jsonista.jmh/decode-data-json  :decode  :throughput  5         80714.396    ops/s  4794.186      {:size "1k"}
jsonista.jmh/decode-data-json  :decode  :throughput  5         7152.868     ops/s  882.978       {:size "10k"}
jsonista.jmh/decode-data-json  :decode  :throughput  5         756.348      ops/s  77.543        {:size "100k"}
jsonista.jmh/decode-cheshire   :decode  :throughput  5         1380506.771  ops/s  61626.508     {:size "10b"}
jsonista.jmh/decode-cheshire   :decode  :throughput  5         526259.733   ops/s  8367.880      {:size "100b"}
jsonista.jmh/decode-cheshire   :decode  :throughput  5         101846.083   ops/s  1052.037      {:size "1k"}
jsonista.jmh/decode-cheshire   :decode  :throughput  5         9493.634     ops/s  177.983       {:size "10k"}
jsonista.jmh/decode-cheshire   :decode  :throughput  5         996.374      ops/s  12.745        {:size "100k"}
jsonista.jmh/decode-jsonista   :decode  :throughput  5         2933372.525  ops/s  40995.514     {:size "10b"}
jsonista.jmh/decode-jsonista   :decode  :throughput  5         686867.379   ops/s  3734.473      {:size "100b"}
jsonista.jmh/decode-jsonista   :decode  :throughput  5         146331.608   ops/s  1187.801      {:size "1k"}
jsonista.jmh/decode-jsonista   :decode  :throughput  5         13509.398    ops/s  248.500       {:size "10k"}
jsonista.jmh/decode-jsonista   :decode  :throughput  5         1363.565     ops/s  10.496        {:size "100k"}
jsonista.jmh/decode-jackson    :decode  :throughput  5         5773791.401  ops/s  31457.861     {:size "10b"}
jsonista.jmh/decode-jackson    :decode  :throughput  5         1379791.334  ops/s  370113.189    {:size "100b"}
jsonista.jmh/decode-jackson    :decode  :throughput  5         245659.626   ops/s  12711.129     {:size "1k"}
jsonista.jmh/decode-jackson    :decode  :throughput  5         23398.618    ops/s  2886.782      {:size "10k"}
jsonista.jmh/decode-jackson    :decode  :throughput  5         2342.444     ops/s  155.288       {:size "100k"}

License

Copyright © 2016-2021 Metosin Oy.

Distributed under the Eclipse Public License 2.0.