[erlang-questions] QR Code Generator

Ulf Wiger <>
Thu Oct 1 08:48:17 CEST 2015


On my Mac (2.5 GHZ Intel Core i7), using all cores, I get the same:

Erlang R16B03-1 (erts-5.10.4) [source] [64-bit] [smp:8:8] [async-threads:10] [hipe] [kernel-poll:false]

Eshell V5.10.4  (abort with ^G)
1> Data = list_to_binary(lists:duplicate(256,$x)).
<<"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"...>>
2> timer:tc(fun() -> lists:foreach(fun(_) -> QR = qrcode:encode(Data), qrcode_demo:simple_png_encode(QR) end, lists:seq(1,5)) end).
{1491915,ok}

If, OTOH, I do this:

3> PEval = fun(F,N) -> Ps = [spawn_monitor(fun() -> exit({ok,F()}) end) || _ <- lists:seq(1,N)], [receive {'DOWN',Ref,_,_,{ok,R}} -> R after 10000 -> error(timeout) end || {_,Ref} <- Ps] end.
#Fun<erl_eval.12.80484245>
4> timer:tc(fun() -> PEval(fun() -> QR = qrcode:encode(Data), qrcode_demo:simple_png_encode(QR) end, 5) end).
{357630, …}

Then, the performance seems to be really there. Is there something I’m missing, that they have to be generated sequentially?

BR,
Ulf

> On 01 Oct 2015, at 00:28, Tony Rogvall <> wrote:
> 
> Data = list_to_binary(lists:duplicate(256,$x)).
> timer:tc(fun() -> lists:foreach(fun(_) -> QR = qrcode:encode(Data), qrcode_demo:simple_png_encode(QR) end, lists:seq(1,5)) end).
> {1401102,ok}
> 
> The performance is nearly there ( running on my mac using only one core )
> 
> /Tony
> 
>> On 1 okt 2015, at 00:13, Theepan < <mailto:>> wrote:
>> 
>> Team,
>> 
>> I am in need of a QR code generator library for Erlang, to generate QR code PNG images of 256 alpha numeric characters.
>> 
>> When I searched the Internet, I found one on GitHub. Have anyone of you used it? Do you have any recommendations?
>> 
>> The performance I need is 5 QR code images generation per second.
>> 
>> Thanks,
>> Theepan
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> 
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Ulf Wiger, Co-founder & Developer Advocate, Feuerlabs Inc.
http://feuerlabs.com



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