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

:benchmark                     :name    :mode        :samples  :score              :score-error  :params
-----------------------------  -------  -----------  --------  ------------------  ------------  --------------
jsonista.jmh/encode-data-json  :encode  :throughput  5         1534830.890  ops/s  155359.246    {:size "10b"}
jsonista.jmh/encode-data-json  :encode  :throughput  5         341613.782   ops/s  26261.051     {:size "100b"}
jsonista.jmh/encode-data-json  :encode  :throughput  5         69673.326    ops/s  1647.625      {:size "1k"}
jsonista.jmh/encode-data-json  :encode  :throughput  5         5658.247     ops/s  999.701       {:size "10k"}
jsonista.jmh/encode-data-json  :encode  :throughput  5         581.924      ops/s  39.758        {:size "100k"}
jsonista.jmh/encode-cheshire   :encode  :throughput  5         1073164.879  ops/s  270854.390    {:size "10b"}
jsonista.jmh/encode-cheshire   :encode  :throughput  5         424662.238   ops/s  146705.515    {:size "100b"}
jsonista.jmh/encode-cheshire   :encode  :throughput  5         101765.336   ops/s  4868.846      {:size "1k"}
jsonista.jmh/encode-cheshire   :encode  :throughput  5         9427.517     ops/s  711.480       {:size "10k"}
jsonista.jmh/encode-cheshire   :encode  :throughput  5         939.962      ops/s  124.443       {:size "100k"}
jsonista.jmh/encode-jsonista   :encode  :throughput  5         6718559.441  ops/s  564494.417    {:size "10b"}
jsonista.jmh/encode-jsonista   :encode  :throughput  5         2021530.135  ops/s  227934.280    {:size "100b"}
jsonista.jmh/encode-jsonista   :encode  :throughput  5         358639.582   ops/s  33561.700     {:size "1k"}
jsonista.jmh/encode-jsonista   :encode  :throughput  5         32536.978    ops/s  8135.004      {:size "10k"}
jsonista.jmh/encode-jsonista   :encode  :throughput  5         2687.242     ops/s  185.516       {:size "100k"}
jsonista.jmh/encode-jackson    :encode  :throughput  5         6883276.103  ops/s  695669.799    {:size "10b"}
jsonista.jmh/encode-jackson    :encode  :throughput  5         1969207.512  ops/s  262952.863    {:size "100b"}
jsonista.jmh/encode-jackson    :encode  :throughput  5         365593.510   ops/s  20251.435     {:size "1k"}
jsonista.jmh/encode-jackson    :encode  :throughput  5         30955.299    ops/s  497.706       {:size "10k"}
jsonista.jmh/encode-jackson    :encode  :throughput  5         2727.378     ops/s  268.712       {:size "100k"}
jsonista.jmh/decode-data-json  :decode  :throughput  5         1576813.105  ops/s  312986.468    {:size "10b"}
jsonista.jmh/decode-data-json  :decode  :throughput  5         395571.705   ops/s  12482.641     {:size "100b"}
jsonista.jmh/decode-data-json  :decode  :throughput  5         63238.895    ops/s  18113.050     {:size "1k"}
jsonista.jmh/decode-data-json  :decode  :throughput  5         5620.609     ops/s  1125.897      {:size "10k"}
jsonista.jmh/decode-data-json  :decode  :throughput  5         601.479      ops/s  43.190        {:size "100k"}
jsonista.jmh/decode-cheshire   :decode  :throughput  5         1066258.082  ops/s  133519.722    {:size "10b"}
jsonista.jmh/decode-cheshire   :decode  :throughput  5         552961.483   ops/s  48478.413     {:size "100b"}
jsonista.jmh/decode-cheshire   :decode  :throughput  5         102688.960   ops/s  2318.402      {:size "1k"}
jsonista.jmh/decode-cheshire   :decode  :throughput  5         9668.507     ops/s  1742.569      {:size "10k"}
jsonista.jmh/decode-cheshire   :decode  :throughput  5         1022.688     ops/s  82.562        {:size "100k"}
jsonista.jmh/decode-jsonista   :decode  :throughput  5         2909222.815  ops/s  162043.029    {:size "10b"}
jsonista.jmh/decode-jsonista   :decode  :throughput  5         681307.555   ops/s  13851.758     {:size "100b"}
jsonista.jmh/decode-jsonista   :decode  :throughput  5         141054.989   ops/s  16569.794     {:size "1k"}
jsonista.jmh/decode-jsonista   :decode  :throughput  5         13235.087    ops/s  1263.748      {:size "10k"}
jsonista.jmh/decode-jsonista   :decode  :throughput  5         1308.170     ops/s  173.721       {:size "100k"}
jsonista.jmh/decode-jackson    :decode  :throughput  5         5783012.047  ops/s  650655.756    {:size "10b"}
jsonista.jmh/decode-jackson    :decode  :throughput  5         1394300.173  ops/s  14904.386     {:size "100b"}
jsonista.jmh/decode-jackson    :decode  :throughput  5         272135.776   ops/s  2335.753      {:size "1k"}
jsonista.jmh/decode-jackson    :decode  :throughput  5         26725.329    ops/s  3507.918      {:size "10k"}
jsonista.jmh/decode-jackson    :decode  :throughput  5         2398.088     ops/s  337.678       {:size "100k"}

License

Copyright © 2016-2020 Metosin Oy.

Distributed under the Eclipse Public License 2.0.