On 13/03/2014 20:48, Jakub Zelenka wrote:
Hi,
Hi Jakub,
I have create a new JSON parser using conditional re2c and pure pull Bison
parser. It's a native UTF-8 parser licensed under PHP license (it can be
used for Evil though :) ). The extension is available at
https://github.com/bukka/php-jsond
Very nice work, thanks!
[snip]
I need to do more testing before creating RFC for replacing the current
parser. There is still space for further improvements. If anyone has any
ideas, please let me know. Or if you could test it, that would be great
too! ;)
For my PhD thesis in the automatic testing domain, I have created some grammar-based testing algorithms, based on our dedicated LL(k) compiler compiler (with its dedicated grammar description language called PP). Please, see the article [1] (along with the presentation [2] and all the details [3] about the article and the conference) and also the tool [4] (called Hoa\Compiler). In this article, my experimentation consisted to generate a lot of JSON strings (based on the JSON grammar [5] written in PP) and compared them against the JSON parsers of Gecko and PHP. Now I re-play this experimentation but I compare all the generated data with ext/json and ext/jsond to see if there is no potential regression. Also, I test it with a bounded exhaustive algorithm: it means we generate all possible JSON strings up to a given size (the unit is the number of tokens in a sequence, so {, true or foo are tokens). Note that we have two ther algorithms: uniform random generation and coverage-based generation.
I have created a little repository to share my work [6]. I have generated all sequences up to 15 tokens, which represents 356'327 data and no one has failed. Congrats!
Just for the record, a good test is a test that fails. Here, I have detected no regeression, and because I have previously compared the ext/json with the JSON parser from Gecko, we can consider your implementation as “safe”.
This is my little contribution of the morning :-). You can use this work to generate data in a static file and use them to compare the memory and CPU usage between ext/json and ext/jsond also.
Best regards.
[1] http://hoa-project.net/Literature/Research/Amost12.html
[2] http://keynote.hoa-project.net/Amost12/EDGB12.pdf
[3] http://hoa-project.net/Event/Amost12.html
[4] https://github.com/hoaproject/Compiler
[5] https://github.com/hoaproject/Json/blob/master/Grammar.pp
[6] https://github.com/Hywan/jsond-test
--
Ivan Enderlin
Developer of Hoa
http://hoa-project.net/
PhD. student at DISC/Femto-ST (Vesontio) and INRIA (Cassis)
http://disc.univ-fcomte.fr/ and http://www.inria.fr/
Member of HTML and WebApps Working Group of W3C
http://w3.org/