benchmark native and json.el #emacs

benchmark-native-json.el

;;; Usage: /path/to/emacs -Q --batch -l /path/to/benchmark-native-json.el
;;; Date: 2019-03-10_15.53.34
(require 'json)

(defconst json-string
  ;; @from https://github.com/syohex/emacs-parson/blob/master/bench/bench.json
  "{
  \"glossary\": {
    \"title\": \"example glossary\",
    \"GlossDiv\": {
      \"title\": \"S\",
      \"GlossList\": {
        \"GlossEntry\": {
          \"ID\": \"SGML\",
          \"SortAs\": \"SGML\",
          \"GlossTerm\": \"Standard Generalized Markup Language\",
          \"Acronym\": \"SGML\",
          \"Abbrev\": \"ISO 8879:1986\",
          \"GlossDef\": {
            \"para\": \"A meta-markup language, used to create markup languages such as DocBook.\",
            \"GlossSeeAlso\": [
              \"GML\",
              \"XML\"
            ]
          },
          \"GlossSee\": \"markup\"
        }
      }
    }
  }
}")

(defmacro run-benchmark (exp)
  `(message "%-66S ;; => %s"
            ',exp
            (let ((inhibit-message t))
              (with-temp-buffer
                ,exp))))

(message (replace-regexp-in-string "\n" "" (emacs-version)))

(run-benchmark (benchmark '100000 '(json-serialize nil)))
(run-benchmark (benchmark '100000 '(json-encode nil)))

(run-benchmark (benchmark '100000 '(json-serialize [1 2 3 4 5])))
(run-benchmark (benchmark '100000 '(json-encode [1 2 3 4 5])))

(run-benchmark (benchmark '100000 '(json-parse-string "[true]")))
(run-benchmark (benchmark '100000 '(json-read-from-string "[true]")))

(run-benchmark (benchmark '100000 '(json-parse-string "{}")))
(run-benchmark (benchmark '100000 '(json-read-from-string "{}")))

(run-benchmark (benchmark '100000 '(json-parse-string json-string)))
(run-benchmark (benchmark '100000 '(json-read-from-string json-string)))

;;; benchmark-native-json.el ends here

~/s/emacs $ src/emacs -Q --batch -l benchmark-native-json.el
GNU Emacs 28.0.50 (build 2, x86_64-apple-darwin18.7.0, NS appkit-1671.60 Version 10.14.6 (Build 18G1012)) of 2020-01-01
(benchmark '100000 '(json-serialize nil))                          ;; => Elapsed time: 0.268941s (0.216736s in 15 GCs)
(benchmark '100000 '(json-encode nil))                             ;; => Elapsed time: 0.122258s (0.208184s in 14 GCs)
(benchmark '100000 '(json-serialize [1 2 3 4 5]))                  ;; => Elapsed time: 0.400901s (0.224517s in 15 GCs)
(benchmark '100000 '(json-encode [1 2 3 4 5]))                     ;; => Elapsed time: 1.883898s (1.276191s in 88 GCs)
(benchmark '100000 '(json-parse-string "[true]"))                  ;; => Elapsed time: 0.220715s (0.236130s in 16 GCs)
(benchmark '100000 '(json-read-from-string "[true]"))              ;; => Elapsed time: 1.983789s (1.286500s in 85 GCs)
(benchmark '100000 '(json-parse-string "{}"))                      ;; => Elapsed time: 0.590364s (0.561388s in 39 GCs)
(benchmark '100000 '(json-read-from-string "{}"))                  ;; => Elapsed time: 2.003027s (1.374641s in 81 GCs)
(benchmark '100000 '(json-parse-string json-string))               ;; => Elapsed time: 11.416063s (7.924459s in 496 GCs)
(benchmark '100000 '(json-read-from-string json-string))           ;; => Elapsed time: 19.642221s (13.262667s in 866 GCs)

It seems json.c was improved in recents months.

https://github.com/emacs-mirror/emacs/commits/master/src/json.c