Reduce binary size about jisho

[eagleflo]

Looking back to this, I've come up with some ideas:

• Switching from JSON files to a binary format like CBOR or MessagePack
• Compressing the JSON files
• Switching to SQLite

Out of these, I'm right now most intrigued by the third option, as it would cut the amount of data into a third right away and provides an extensible base for future needs. I'll give it a try.

[eagleflo]

It's quite cumbersome to try to read an SQLite database that's embedded in the binary. I might come back to this approach later, but for now I'll just compress the JSON files with flate2. This is already a marked improvement.

[eagleflo]

Compressing the JSON files results in the binary shrinking from 121MB to 32MB... however, this also results in a hefty performance degradation:

~/jisho (compress-dictionaries) % ./bench
    Finished release [optimized] target(s) in 0.02s
Benchmark 1: cargo run --release 緑
  Time (mean ± σ):     285.1 ms ±   4.3 ms    [User: 205.4 ms, System: 79.0 ms]
  Range (min … max):   279.6 ms … 294.7 ms    10 runs

Benchmark 1: cargo run --release みどり
  Time (mean ± σ):     326.9 ms ±   6.6 ms    [User: 234.9 ms, System: 91.2 ms]
  Range (min … max):   321.6 ms … 344.8 ms    10 runs

Benchmark 1: cargo run --release green
  Time (mean ± σ):     641.5 ms ±   4.5 ms    [User: 496.0 ms, System: 144.1 ms]
  Range (min … max):   635.1 ms … 648.4 ms    10 runs

compared to

~/jisho (main) % ./bench
   Compiling jisho v0.1.7 (/home/aku/jisho)
    Finished release [optimized] target(s) in 22.98s
Benchmark 1: cargo run --release 緑
  Time (mean ± σ):     204.7 ms ±   1.9 ms    [User: 137.3 ms, System: 66.8 ms]
  Range (min … max):   201.6 ms … 207.8 ms    14 runs

Benchmark 1: cargo run --release みどり
  Time (mean ± σ):     232.6 ms ±   2.7 ms    [User: 147.5 ms, System: 84.2 ms]
  Range (min … max):   229.0 ms … 237.6 ms    12 runs

Benchmark 1: cargo run --release green
  Time (mean ± σ):     448.2 ms ±   4.7 ms    [User: 295.3 ms, System: 151.7 ms]
  Range (min … max):   441.0 ms … 454.0 ms    10 runs

Slowing down the quick CLI lookup usecase by 50% is a dealbreaker. I'll figure out something else.