Call self_closing_tags only once on raw_html

[ypconstante]

self_closing_tags is not a slow function, but today it is called thousands of times while generating the raw html, which ends up causing a significant performance impact.

This PR modifies the RawHTML module to call self_closing_tags() only once on raw_html, sending the value as params to the other functions. raw_html also converts closing tags to MapSet to help speed up the check .

##### With input big #####
Name                 ips        average  deviation         median         99th %
bench (pr)         61.60       16.23 ms    ±14.47%       15.99 ms       21.96 ms
bench              39.96       25.03 ms     ±9.18%       24.86 ms       31.23 ms

Comparison: 
bench (pr)         61.60
bench              39.96 - 1.54x slower +8.79 ms

Memory usage statistics:

Name          Memory usage
bench (pr)         8.47 MB
bench              9.49 MB - 1.12x memory usage +1.02 MB

**All measurements for memory usage were the same**

##### With input medium #####
Name                 ips        average  deviation         median         99th %
bench (pr)        197.42        5.07 ms    ±24.27%        4.80 ms        9.11 ms
bench             124.30        8.05 ms    ±14.06%        7.77 ms       11.08 ms

Comparison: 
bench (pr)        197.42
bench             124.30 - 1.59x slower +2.98 ms

Memory usage statistics:

Name          Memory usage
bench (pr)         2.95 MB
bench              3.31 MB - 1.12x memory usage +0.36 MB

**All measurements for memory usage were the same**

##### With input small #####
Name                 ips        average  deviation         median         99th %
bench (pr)        1.26 K        0.79 ms    ±10.28%        0.77 ms        1.10 ms
bench             0.74 K        1.35 ms    ±10.38%        1.30 ms        1.83 ms

Comparison: 
bench (pr)        1.26 K
bench             0.74 K - 1.70x slower +0.55 ms

Memory usage statistics:

Name          Memory usage
bench (pr)       645.78 KB
bench            720.79 KB - 1.12x memory usage +75.01 KB

**All measurements for memory usage were the same**

read_file = fn name ->
  __ENV__.file
  |> Path.dirname()
  |> Path.join(name)
  |> File.read!()
  |> Floki.parse_document!()
end

inputs = %{
  "big" => read_file.("big.html"),
  "medium" => read_file.("medium.html"),
  "small" => read_file.("small.html")
}

Benchee.run(
  %{
    "bench" => &Floki.raw_html/1
  },
  time: 10,
  inputs: inputs,
  memory_time: 2,
)

[philss]

Awesome! 🚀

[philss]

Just curious: did you find MapSet faster than using a List with unique elements?

[ypconstante]

I did some tests, and it seems that performance is the same for this case, I reverted back to list 4d53e0f

[philss]

@ypconstante thank you! 💜