Faster string generator

[kachick]

ref: #102, https://github.com/kachick/ruby-ulid/wiki/Benchmark, https://github.com/rbspy/rbspy, https://github.com/tmm1/stackprof

Just use cache does not make much faster.

Before

#### kachick - ruby-ulid(This one)
cd ./benchmark/compare_with_othergems/kachick
bundle install --quiet
bundle exec ruby -v ./generate.rb
ruby 3.1.2p20 (2022-04-12 revision 4491bb740a) [x86_64-linux]
Warming up --------------------------------------
  ULID.generate.to_s     6.555k i/100ms
Calculating -------------------------------------
  ULID.generate.to_s     62.171k (±10.6%) i/s -    308.085k in   5.015662s
"`ruby-ulid gem (this one) - 0.5.0` generated products: 439170 - sample: [\"01G86P982YH0Z09JQ3VD1K6SSD\", \"01G86P96SMW2CSG0379AGMQ1XC\", \"01G86P9AYMMBHXEM4G70EF47BB\", \"01G86P9BC89AZGPXVT7N6PRT58\", \"01G86P99KFFRSJAY10TBJ4BS67\"]"
cd -

After

❯ rake benchmark_with_other_gems
#### kachick - ruby-ulid(This one)
cd ./benchmark/compare_with_othergems/kachick
bundle install --quiet
bundle exec ruby -v ./generate.rb
ruby 3.1.2p20 (2022-04-12 revision 4491bb740a) [x86_64-linux]
Warming up --------------------------------------
         ULID.encode     7.080k i/100ms
Calculating -------------------------------------
         ULID.encode     64.003k (±10.0%) i/s -    318.600k in   5.031231s
"`ruby-ulid gem (this one) - 0.6.0.pre` generated products: 454935 - sample: [\"01G86NV9B5ZMRH7SZK0BZYJT48\", \"01G86NV76W39M9YY9X93E2X4JV\", \"01G86NVB235XFQ09MKH3626AB2\", \"01G86NVCXDFX6SRE6148XVFN9X\", \"01G86NVAY1GWNWE4VMRY2497ZT\"]"

Do stackprof

❯ rake stackprof
bundle exec ruby ./scripts/prof.rb
bundle exec stackprof tmp/stackprof-wall-*.dump --text --limit 1
==================================
  Mode: wall(1000)
  Samples: 1301 (0.00% miss rate)
  GC: 225 (17.29%)
==================================
     TOTAL    (pct)     SAMPLES    (pct)     FRAME
       481  (37.0%)         481  (37.0%)     String#gsub
bundle exec stackprof tmp/stackprof-cpu-*.dump --text --limit 1
==================================
  Mode: cpu(1000)
  Samples: 131 (0.00% miss rate)
  GC: 24 (18.32%)
==================================
     TOTAL    (pct)     SAMPLES    (pct)     FRAME
        54  (41.2%)          54  (41.2%)     String#gsub

Replacing String#gsub with String#tr makes almost 2x faster. And now bottleneck is mandatory random generator.

❯ rake stackprof
bundle exec ruby ./scripts/prof.rb
bundle exec stackprof tmp/stackprof-wall-*.dump --text --limit 1
==================================
  Mode: wall(1000)
  Samples: 695 (0.00% miss rate)
  GC: 66 (9.50%)
==================================
     TOTAL    (pct)     SAMPLES    (pct)     FRAME
       280  (40.3%)         280  (40.3%)     Random.urandom
bundle exec stackprof tmp/stackprof-cpu-*.dump --text --limit 1
==================================
  Mode: cpu(1000)
  Samples: 68 (0.00% miss rate)
  GC: 11 (16.18%)
==================================
     TOTAL    (pct)     SAMPLES    (pct)     FRAME
        29  (42.6%)          29  (42.6%)     Random.urandom

❯ rake benchmark/generate_vs_encode.rb
/home/kachick/.rubies/ruby-3.1.2/bin/ruby benchmark/generate_vs_encode.rb
Warming up --------------------------------------
  ULID.generate.to_s    12.980k i/100ms
         ULID.encode    14.573k i/100ms
Calculating -------------------------------------
  ULID.generate.to_s    131.198k (± 5.7%) i/s -    661.980k in   5.066869s
         ULID.encode    147.106k (± 3.7%) i/s -    743.223k in   5.059546s

Comparison:
         ULID.encode:   147105.5 i/s
  ULID.generate.to_s:   131197.8 i/s - 1.12x  (± 0.00) slower

Now this gem is almost 1.5x faster than other major gems (As far as I know in pure ruby)

❯ rake benchmark_with_other_gems
------------------------------------------------------------------------
#### kachick - ruby-ulid(This one)
cd ./benchmark/compare_with_othergems/kachick
bundle install --quiet
bundle exec ruby -v ./generate.rb
ruby 3.1.2p20 (2022-04-12 revision 4491bb740a) [x86_64-linux]
Warming up --------------------------------------
         ULID.encode    12.363k i/100ms
Calculating -------------------------------------
         ULID.encode    119.758k (±14.3%) i/s -    593.424k in   5.071896s
"`ruby-ulid gem (this one) - 0.6.0.pre` generated products: 832041 - sample: [\"01G86TFTMSMAYPX24J3NWBYB3N\", \"01G86TFW3TS0YSNR3RY6E5SRDF\", \"01G86TFSH3YM4FCQB5W4VARCZV\", \"01G86TFX92QKAJXC3ADCA1J662\", \"01G86TFV0QYWNKD2NHH88YW57H\"]"
cd -
------------------------------------------------------------------------
#### rafaelsales - ulid
cd ./benchmark/compare_with_othergems/rafaelsales
bundle install --quiet
bundle exec ruby -v ./generate.rb
ruby 3.1.2p20 (2022-04-12 revision 4491bb740a) [x86_64-linux]
Warming up --------------------------------------
       ULID.generate     9.128k i/100ms
Calculating -------------------------------------
       ULID.generate     82.906k (±11.0%) i/s -    410.760k in   5.026247s
"`ulid gem - 1.3.0` generated products: 585831 - sample: [\"01G86TG68FGBY0VCGENC9YC3NT\", \"01G86TG6A788TJQ8BB29MQYS2Q\", \"01G86TG7JNWXWP5G1NDSS8K00J\", \"01G86TG54JVTPN4ZNNWQYCVVEE\", \"01G86TG3S0RPSMRM1EYGPDJX9D\"]"
cd -
------------------------------------------------------------------------
#### abachman - ulid-ruby
cd ./benchmark/compare_with_othergems/abachman
bundle install --quiet
bundle exec ruby -v ./generate.rb
ruby 3.1.2p20 (2022-04-12 revision 4491bb740a) [x86_64-linux]
Warming up --------------------------------------
       ULID.generate     7.454k i/100ms
Calculating -------------------------------------
       ULID.generate     67.697k (±10.4%) i/s -    335.430k in   5.011842s
"`ulid-ruby gem - 1.0.2` generated products: 475505 - sample: [\"01G86TGA3T4HWA3MR4YDQSS4NV\", \"01G86TGE7BZJMDKPDMJCH9F00X\", \"01G86TGAA4414FF9GG1AV2M8HX\", \"01G86TGFKZXWFP06XAMW5V57Q5\", \"01G86TGAFER6BH0Q3DVJW5EAWD\"]"
cd -

irb(main):002:0> Rational(119.758, 82.906).to_f
=> 1.4445034135044508
irb(main):003:0> Rational(119.758, 67.697).to_f
=> 1.7690296468085733

🎉 ⚡

[kachick]

no confidence for the namings…