Re: Vague question about lpeg performance

[Jerome Vuarand <jerome.vuarand@...>]

2010/4/3 Stefan <stefan@chehalispost.com>:
> Jerome Vuarand wrote:
>>
>> 2010/4/2 Stefan <stefan@chehalispost.com>:
>>>
>>> Perhaps a benchmark is in order?
>>>
>>> YAJL is reportedly among the fastest C JSON libs around. There is a Lua
>>> module for it here:
>>>
>>> http://github.com/brimworks/lua-yajl/
>>>
>>> A trivial bench between lua-yajl and json4lua encoding a small array
>>> 100,000
>>> times shows this:
>>>
>>> alpha# time lua-5.1 yajltest.lua
>>> 3.967u 0.000s 0:03.97 99.7%     177+983k 0+0io 0pf+0w
>>>
>>> alpha# time lua-5.1 jsontest.lua
>>> 9.170u 0.000s 0:09.17 100.0%    175+973k 0+0io 0pf+0w
>>>
>>> 230% faster is what I am seeing - YMMV
>>
>> Thanks for the tip. lua-yajl decoding seems to be about 18% faster
>> than luajson, and encoding is 400% faster. But it seems to be a work
>> in progress, and it's less complete than luajson, so I guess I won't
>> switch just now.
>>
>
> Is that using the "recommended" Lua to_value(string) decoding convenience
> function? If so, then once it is implemented within the C module itself one
> would expect to see equally impressive improvement (as encoding)

The C to_value is not implemented, so I adapted the
half-Lua/half-JavaScript example in the README file to Lua.

> But yes, I think he 1.0ed it a wee bit too soon...

I was looking for something more mature. Compiling it was a pain
(especially due to the requirement of CMake 2.6+), compared to the
"sudo luarocks install luajson". Given the missing part (to_value) and
the lack of compatibility with luajson, I'd rather roll my own yajl
binding.