docs/performance.rst

Performance
===========

This library is written in Cython for a better performance than a pure-Python implementation could give you.


Decoder Performance
-------------------

The library has about the same speed as the shipped ``json`` module for *pure* JSON data.

* Dataset: https://github.com/zemirco/sf-city-lots-json
* Version: Python 3.9.1+ (default, Feb  5 2021, 13:46:56)
* CPU: AMD Ryzen 7 2700 @ 3.7GHz
* :func:`pyjson5.decode`: **2.08 s** ± 7.49 ms per loop *(lower is better)*
* :func:`json.loads`: **2.71 s** ± 12.1 ms per loop
* The decoder works correcty: ``json.loads(content) == pyjson5.loads(content)``


Encoder Performance
-------------------

The encoder generates pure JSON data if there are no infinite or NaN values in the input, which are invalid in JSON.
The serialized data is XML-safe, i.e. there are no cheverons ``<>``, ampersands ``&``, apostrophes ``'`` or control characters in the output.
The output is always ASCII regardless if you call :func:`pyjson5.encode` or :func:`pyjson5.encode_bytes`.

* Dataset: https://github.com/zemirco/sf-city-lots-json
* Python 3.9.1+ (default, Feb  5 2021, 13:46:56) 
* CPU: AMD Ryzen 7 2700 @ 3.7GHz
* :func:`pyjson5.encode`: **1.37** s ± 19.2 per loop *(lower is better)*
* :func:`json.dumps`: **3.66** s ± 72.6 ms per loop
* :func:`json.dumps` + :func:`xml.sax.saxutils.escape`: **4.01** s ± 21.3 ms per loop
* The encoder works correcty: ``obj == json.loads(pyjson5.encode(obj))``


Benchmark
---------

Using `Ultrajson's benchmark <https://github.com/ultrajson/ultrajson/blob/197a7fd4d8bbf0a8355852017c8b25aab26b6777/tests/benchmark.py>`_
you can tell for which kind of data PyJSON5 is fast, and for which data it is slow in comparison *(higher is better)*:

+-----------------------------------------------------------+-------------+------------+------------+------------+
|                                                           |  json       | pyjson5    | ujson      | orjson     |
+===========================================================+=============+============+============+============+
| **Array with 256 doubles**                                |             |            |            |            |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| encode                                                    |       6,425 |     81,202 |     28,966 |     83,836 |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| decode                                                    |      16,759 |     34,801 |     34,794 |     80,655 |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| **Array with 256 strings**                                |             |            |            |            |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| encode                                                    |      36,969 |     73,165 |     35,574 |    113,082 |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| decode                                                    |      42,730 |     38,542 |     38,386 |     60,732 |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| **Array with 256 UTF-8 strings**                          |             |            |            |            |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| encode                                                    |       3,458 |      3,134 |      4,024 |     31,677 |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| decode                                                    |       2,428 |      2,498 |      2,491 |      1,750 |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| **Array with 256 True values**                            |             |            |            |            |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| encode                                                    |     130,441 |    282,703 |    131,279 |    423,371 |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| decode                                                    |     220,657 |    262,690 |    264,485 |    262,283 |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| **Array with 256 dict{string, int} pairs**                |             |            |            |            |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| encode                                                    |      11,621 |     10,014 |     18,148 |     73,905 |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| decode                                                    |      17,802 |     19,406 |     19,391 |     23,478 |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| **Dict with 256 arrays with 256 dict{string, int} pairs** |             |            |            |            |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| encode                                                    |          40 |         38 |         68 |        213 |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| decode                                                    |          43 |         49 |         48 |         51 |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| **Medium complex object**                                 |             |            |            |            |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| encode                                                    |       8,704 |     11,922 |     15,319 |     49,677 |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| decode                                                    |      12,567 |     14,042 |     13,985 |     19,481 |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| **Complex object**                                        |             |            |            |            |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| encode                                                    |         672 |        909 |        731 |            |
+-----------------------------------------------------------+-------------+------------+------------+------------+
| decode                                                    |         462 |        700 |        700 |            |
+-----------------------------------------------------------+-------------+------------+------------+------------+

* `ujson <https://github.com/ultrajson/ultrajson>`_ == 4.0.3.dev9
* `orjson <https://github.com/ijl/orjson>`_ == 3.5.1