This gem (although not in gem form just yet) is a C binding to the excellent YAJL JSON parsing library.
First, you're probably gonna want to include it:
Then maybe parse some JSON from:
a File IO
json_contents = File.new('test.json', 'r') hash = Yajl::Native.parse(json)
or maybe a StringIO
json_contents = StringIO.new hash = Yajl::Native.parse(json)
or maybe STDIN
cat someJsonFile.json | ruby -ryajl -e "puts Yajl::Native.parse(STDIN).inspect"
There are a lot more possibilities, some of which I'm going to write other gems/plugins for.
Some ideas are:
parsing logs in JSON format
an ActiveSupport patch (github.com/technoweenie/rails/commit/f9abcc93a3660fcf46172c4cd8a2f36ba5a5510d)
Rack middleware (ideally the JSON body could be handed to the parser while it's still being received)
use with ohai
JSON API clients
First, Yajl uses CMake to build itself (yes, the author realizes this isn't the norm for open source and is willing and ready to accept patches, fork away kids!) so you'll need to grab it first from www.cmake.org.
After you've got that, grab the latest version of Yajl itself from the Githubs at github.com/lloyd/yajl.
After you have that installed, you should be able to install it like any other gem hosted here like so:
(more instructions here: gems.github.com)
sudo gem install brianmario-yajl-ruby
I'll update this readme with some actual data soon.
After I finished implementation - this library performs close to the same as the current JSON.parse (C gem) does on small/medium files.
But on larger files, and higher amounts of iteration, this library was around 2x faster than JSON.parse.
The main benefit of this library is in it's memory usage.
Since it's able to parse the stream in chunks, it's memory requirements are very, very low.
Again, I'll post some actual data on this; but in my testing here's what my ruby executable was using to parse a 10MB JSON file 100 times:
JSON.parse ~60MB Yajl::Native.parse ~30MB
This library is still being refined and should by no means be used in production. That being said, I'd like to invite you to clone/fork and test the crap out of it! ;)
While parsing is working for the most part, there are still some edge cases I need to tackle. Here's a list of things I need to get done to improve the awesomeness of this library.
Write up a test suite
Fix known parsing issues with certain JSON strings (Yajl itself works fine, it's the logic in this library that needs a little tweaking)
Write more docs
Change API so it can accept a String or an IO