Performance comparison
----------------------

Here is a rough performance comparision of several JSON packages
available for Lua:

- DKJSON 1.0: One of the fastest pure Lua JSON implementations.
- LuaJSON 1.0: A mixed Lua/C JSON implementation using LPeg.
- CSJON 1.0: Pure C.

The example JSON files used were taken from http://json.org/ and
RFC 4627.

                        === DKJSON ===  == LuaJSON ===  === CJSON ====
== Decoding ==          Lua     LuaJIT  Lua     LuaJIT  Lua     LuaJIT
example1.json           1.0x    1.9x    3.4x    3.9x    12.3x   13.7x
example2.json           1.0x    2.0x    3.6x    4.6x    12.2x   20.0x
example3.json           1.0x    2.0x    3.9x    4.7x    13.1x   18.8x
example4.json           1.0x    1.8x    3.7x    4.4x    11.9x   17.0x
example5.json           1.0x    1.5x    4.0x    4.8x    14.6x   22.2x
rfc-example1.json       1.0x    1.5x    3.2x    4.3x    11.7x   16.9x
rfc-example2.json       1.0x    1.5x    3.7x    4.5x    10.3x   19.4x
== Average ==>          1.0x    1.7x    3.5x    4.2x    11.3x   16.5x

== Encoding ==                                           
example1.json           1.0x    1.8x    0.6x    1.4x    23.5x   23.4x
example2.json           1.0x    2.0x    0.5x    1.2x    22.4x   22.4x
example3.json           1.0x    1.8x    0.6x    1.3x    10.8x   13.4x
example4.json           1.0x    1.2x    0.7x    1.5x    15.7x   17.2x
example5.json           1.0x    1.5x    0.6x    1.4x    22.1x   20.4x
rfc-example1.json       1.0x    1.4x    0.5x    1.1x    8.9x    9.2x
rfc-example2.json       1.0x    1.4x    0.6x    1.3x    10.4x   10.9x
== Average ==>          1.0x    1.6x    0.6x    1.3x    17.0x   17.2x


CJSON spends a significant amount of time calling sprintf() to convert
doubles to strings while encoding "rfc-example1.json". Hence it only
shows a 9x improvement in this case.

The performance gains available can vary widely. If performance is
critical, I would recommend testing in a relevant environment with
your intended data.