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         406998.934   ops/s  152242.102    {:size "10b"}
jsonista.jmh/encode-data-json  :encode  :throughput  5         146750.626   ops/s  13532.113     {:size "100b"}
jsonista.jmh/encode-data-json  :encode  :throughput  5         28543.913    ops/s  5982.429      {:size "1k"}
jsonista.jmh/encode-data-json  :encode  :throughput  5         1994.604     ops/s  193.798       {:size "10k"}
jsonista.jmh/encode-data-json  :encode  :throughput  5         229.534      ops/s  3.574         {:size "100k"}
jsonista.jmh/encode-cheshire   :encode  :throughput  5         1202854.746  ops/s  63201.698     {:size "10b"}
jsonista.jmh/encode-cheshire   :encode  :throughput  5         468291.944   ops/s  37267.515     {:size "100b"}
jsonista.jmh/encode-cheshire   :encode  :throughput  5         108479.571   ops/s  2483.284      {:size "1k"}
jsonista.jmh/encode-cheshire   :encode  :throughput  5         10293.254    ops/s  92.099        {:size "10k"}
jsonista.jmh/encode-cheshire   :encode  :throughput  5         1060.651     ops/s  4.026         {:size "100k"}
jsonista.jmh/encode-jsonista   :encode  :throughput  5         6783801.957  ops/s  54798.388     {:size "10b"}
jsonista.jmh/encode-jsonista   :encode  :throughput  5         2261881.877  ops/s  41683.847     {:size "100b"}
jsonista.jmh/encode-jsonista   :encode  :throughput  5         394457.058   ops/s  4225.290      {:size "1k"}
jsonista.jmh/encode-jsonista   :encode  :throughput  5         35557.637    ops/s  532.431       {:size "10k"}
jsonista.jmh/encode-jsonista   :encode  :throughput  5         3060.934     ops/s  101.250       {:size "100k"}
jsonista.jmh/encode-jackson    :encode  :throughput  5         6272986.538  ops/s  8067758.467   {:size "10b"}
jsonista.jmh/encode-jackson    :encode  :throughput  5         1554381.542  ops/s  2291008.911   {:size "100b"}
jsonista.jmh/encode-jackson    :encode  :throughput  5         275663.380   ops/s  258073.341    {:size "1k"}
jsonista.jmh/encode-jackson    :encode  :throughput  5         30998.301    ops/s  7629.493      {:size "10k"}
jsonista.jmh/encode-jackson    :encode  :throughput  5         2848.233     ops/s  248.972       {:size "100k"}
jsonista.jmh/decode-data-json  :decode  :throughput  5         910109.735   ops/s  5590.181      {:size "10b"}
jsonista.jmh/decode-data-json  :decode  :throughput  5         245111.831   ops/s  2604.368      {:size "100b"}
jsonista.jmh/decode-data-json  :decode  :throughput  5         42535.710    ops/s  647.046       {:size "1k"}
jsonista.jmh/decode-data-json  :decode  :throughput  5         3705.661     ops/s  21.401        {:size "10k"}
jsonista.jmh/decode-data-json  :decode  :throughput  5         412.894      ops/s  4.897         {:size "100k"}
jsonista.jmh/decode-cheshire   :decode  :throughput  5         1440650.958  ops/s  63665.904     {:size "10b"}
jsonista.jmh/decode-cheshire   :decode  :throughput  5         538246.521   ops/s  5078.053      {:size "100b"}
jsonista.jmh/decode-cheshire   :decode  :throughput  5         110073.963   ops/s  4482.999      {:size "1k"}
jsonista.jmh/decode-cheshire   :decode  :throughput  5         9422.709     ops/s  763.989       {:size "10k"}
jsonista.jmh/decode-cheshire   :decode  :throughput  5         991.322      ops/s  65.215        {:size "100k"}
jsonista.jmh/decode-jsonista   :decode  :throughput  5         2463256.808  ops/s  233941.924    {:size "10b"}
jsonista.jmh/decode-jsonista   :decode  :throughput  5         606524.401   ops/s  24347.671     {:size "100b"}
jsonista.jmh/decode-jsonista   :decode  :throughput  5         143850.780   ops/s  26755.413     {:size "1k"}
jsonista.jmh/decode-jsonista   :decode  :throughput  5         13433.671    ops/s  1946.566      {:size "10k"}
jsonista.jmh/decode-jsonista   :decode  :throughput  5         1214.055     ops/s  204.500       {:size "100k"}
jsonista.jmh/decode-jackson    :decode  :throughput  5         6098939.624  ops/s  768530.918    {:size "10b"}
jsonista.jmh/decode-jackson    :decode  :throughput  5         1435602.777  ops/s  20860.504     {:size "100b"}
jsonista.jmh/decode-jackson    :decode  :throughput  5         274066.827   ops/s  2922.479      {:size "1k"}
jsonista.jmh/decode-jackson    :decode  :throughput  5         25650.308    ops/s  1388.505      {:size "10k"}
jsonista.jmh/decode-jackson    :decode  :throughput  5         2569.702     ops/s  13.894        {:size "100k"}

License

Copyright © 2016-2020 Metosin Oy.

Distributed under the Eclipse Public License 2.0.