Rust JSON Benchmark

This is a partial port of nativejson-benchmark to Rust. The libraries tested are:

• serde_json 1.0.35
• json-rust 0.11.13
• rustc-serialize 0.3.24

$ cargo run --release --bin json-benchmark

                                DOM                STRUCT
======= serde_json ======= parse|stringify ===== parse|stringify ====
data/canada.json         200 MB/s   390 MB/s   550 MB/s   320 MB/s
data/citm_catalog.json   290 MB/s   370 MB/s   860 MB/s   790 MB/s
data/twitter.json        260 MB/s   850 MB/s   550 MB/s   940 MB/s

======= json-rust ======== parse|stringify ===== parse|stringify ====
data/canada.json         270 MB/s   830 MB/s
data/citm_catalog.json   560 MB/s   660 MB/s
data/twitter.json        420 MB/s   870 MB/s

==== rustc_serialize ===== parse|stringify ===== parse|stringify ====
data/canada.json         130 MB/s    60 MB/s   100 MB/s    45 MB/s
data/citm_catalog.json   130 MB/s   140 MB/s    97 MB/s   200 MB/s
data/twitter.json         92 MB/s   330 MB/s    69 MB/s   350 MB/s

• Intel(R) Core(TM) i7-6600U CPU @ 2.60GHz (laptop CPU from 2015)
• rustc 1.33.0-nightly (75a369c5b 2019-01-12)

To update the numbers above, I run ./json-benchmark -n 256 twice on an otherwise idle computer and take the greater of the two results for each number.

For comparison, here are results from RapidJSON on the same hardware with the nativejson-benchmark modified to run 256 times instead of 10.

==== rapidjson-clang ===================== parse|stringify ====
data/canada.json                         390 MB/s   200 MB/s
data/citm_catalog.json                   670 MB/s   290 MB/s
data/twitter.json                        340 MB/s   370 MB/s

===== rapidjson-gcc ====================== parse|stringify ====
data/canada.json                         470 MB/s   240 MB/s
data/citm_catalog.json                   990 MB/s   480 MB/s
data/twitter.json                        470 MB/s   620 MB/s

• clang version 3.8.0
• gcc version 5.4.0