simdjson performance demonstration

This is a simple example where we seek to query a few key/value pairs from a sizeable json document. We examine two different approaches.

Usage:

make
./main test.json

Optionally:

sudo ./main test.json

Sample results

Apple M2, LLVM 14:

read_file                      :   0.96 GB/s   3.88 GHz    4.0 c/b  15.85 i/b   3.93 i/c 
two_pass_read_file             :   0.94 GB/s   3.88 GHz    4.1 c/b  16.77 i/b   4.06 i/c 
read_json                      :   3.49 GB/s   5.01 GHz    1.4 c/b   7.90 i/b   5.50 i/c 
fast_read_json                 :   4.93 GB/s   5.89 GHz    1.2 c/b   6.47 i/b   5.41 i/c 
file load + fast_read_json     :   0.89 GB/s   3.85 GHz    4.3 c/b  19.36 i/b   4.46 i/c 

Linux, Ice Lake, GCC 12:

read_file                      :   2.28 GB/s   1.01 GHz    0.4 c/b   0.35 i/b   0.79 i/c
two_pass_read_file             :   2.10 GB/s   0.69 GHz    0.3 c/b   0.42 i/b   1.27 i/c
read_json                      :   2.47 GB/s   3.15 GHz    1.3 c/b   4.44 i/b   3.48 i/c
fast_read_json                 :   4.29 GB/s   3.19 GHz    0.7 c/b   2.64 i/b   3.54 i/c
file load + fast_read_json     :   1.43 GB/s   1.70 GHz    1.2 c/b   2.97 i/b   2.50 i/c