You’re all making me want to implement Jason.Native again!

The Ruby parser is implemented in C, so it’s more like comparing C to Elixir. Obviously C is going to be faster We’re not doing that bad actually. It would be interesting to compare with Jason compiled with HiPE. In my benchmarks this makes it at least twice as fast.

The data is also quite different from what you’d face in a regular HTTP app - the JSON is pretty-printed, most JSON flying on the wire is not. This can have significant difference in the actual performance. Depending on what you want to learn from this, it can be important.

Let’s have some fun, here is how they compare to C++/rapidjson:

# Golang
$ time jq '.' data/10mb.json > /dev/null

real    0m0.607s
user    0m0.603s
sys     0m0.004s

$ time jq '.' data/citylots.json > /dev/null

real    0m14.348s
user    0m13.839s
sys     0m0.504s

# Elixir
## 10mb.json
Time taken [Jason]: 521.655ms
Time taken [Poison]: 1358.531ms
## citylots.json
Time taken [Jason]: 12224.44ms
Time taken [Poison]: 33350.239ms

# Ruby
## 10mb.json
$ time ruby app.rb

real    0m0.350s
user    0m0.250s
sys     0m0.020s
## citylots.json
$ time ruby app.rb

real    0m5.632s
user    0m5.393s
sys     0m0.236s

# C++
$ time ./rapidjson-testing < ../../benchmark-large-json-parsing/data/10mb.json 

real    0m0.035s
user    0m0.034s
sys     0m0.000s

$ time ./rapidjson-testing < ../../benchmark-large-json-parsing/data/citylots.json 

real    0m0.531s
user    0m0.503s
sys     0m0.028s

Admittedly this benchmark is flawed because jq is outputting to stdout and elixir/ruby/C++ are just kind of blackholing the data after it is parsed, so jq/go is artificially limited here. In addition the elixir version is actually instancing a tree to hold the whole structure, which is wasted work as well (unsure about ruby). The C++ version is fully parsing and performing callbacks for every parse (standard sax parsing).

I can PR the C++ one in it if you want, it only needs the normal C++ compiler and cmake installed, nothing else needed (not even rapidjson, it acquires it itself).