Optimize traverse_and_update without accumulator

[ypconstante]

Today traverse_and_update/2 calls the same traverse functions as traverse_and_update/3, so the traverse keeps creating a bunch of tuples to store the accumulator value unnecessarily.

This PR optimizes traverse_and_update/2 by avoiding this tuples, it required basically duplicating the traverse functions, since the implementation is small it shouldn't be an issue.

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(
  %{
    "delete footer-poweredbyico" => fn doc ->
      Floki.traverse_and_update(doc, fn node ->
        if Floki.attribute(node, "id") == ["footer-poweredbyico"] do
          nil
        else
          node
        end
      end)
    end,
    "do nothing" => fn doc ->
      Floki.traverse_and_update(doc, &Function.identity/1)
    end,
    "reverse all children" => fn doc ->
      Floki.traverse_and_update(doc, fn
        {elem, attrs, children} -> {elem, attrs, Enum.reverse(children)}
        node -> node
      end)
    end
  },
  time: 10,
  inputs: inputs,
  save: [path: "benchs/results/raw-html-#{tag}.benchee", tag: tag],
  memory_time: 2
)

##### With input big #####
Name                                        ips        average  deviation         median         99th %
do nothing (pr)                          581.63        1.72 ms    ±54.58%        2.29 ms        2.90 ms
reverse all children (pr)                335.23        2.98 ms     ±6.86%        2.97 ms        3.64 ms
delete footer-poweredbyico (pr)          231.10        4.33 ms    ±22.97%        3.87 ms        6.11 ms
do nothing (main)                        214.01        4.67 ms     ±7.65%        4.66 ms        5.40 ms
reverse all children (main)              197.61        5.06 ms    ±23.27%        4.90 ms        7.44 ms
delete footer-poweredbyico (main)        172.87        5.78 ms    ±30.27%        5.92 ms        8.32 ms

Comparison:
do nothing (pr)                          581.63
reverse all children (pr)                335.23 - 1.73x slower +1.26 ms
delete footer-poweredbyico (pr)          231.10 - 2.52x slower +2.61 ms
do nothing (main)                        214.01 - 2.72x slower +2.95 ms
reverse all children (main)              197.61 - 2.94x slower +3.34 ms
delete footer-poweredbyico (main)        172.87 - 3.36x slower +4.07 ms

Memory usage statistics:

Name                                 Memory usage
do nothing (pr)                           1.00 MB
reverse all children (pr)                 1.83 MB - 1.83x memory usage +0.83 MB
delete footer-poweredbyico (pr)           2.29 MB - 2.29x memory usage +1.29 MB
do nothing (main)                         2.87 MB - 2.86x memory usage +1.86 MB
reverse all children (main)               3.70 MB - 3.68x memory usage +2.69 MB
delete footer-poweredbyico (main)         4.16 MB - 4.14x memory usage +3.15 MB

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

##### With input medium #####
Name                                        ips        average  deviation         median         99th %
do nothing (pr)                          4.12 K        0.24 ms    ±11.05%        0.23 ms        0.34 ms
reverse all children (pr)                3.26 K        0.31 ms    ±11.17%        0.29 ms        0.42 ms
reverse all children (main)              2.61 K        0.38 ms     ±7.61%        0.38 ms        0.49 ms
do nothing (main)                        0.85 K        1.17 ms    ±27.36%        0.99 ms        1.77 ms
delete footer-poweredbyico (pr)          0.84 K        1.19 ms    ±12.74%        1.17 ms        1.87 ms
delete footer-poweredbyico (main)        0.56 K        1.80 ms     ±4.57%        1.79 ms        2.07 ms

Comparison:
do nothing (pr)                          4.12 K
reverse all children (pr)                3.26 K - 1.26x slower +0.0636 ms
reverse all children (main)              2.61 K - 1.58x slower +0.141 ms
do nothing (main)                        0.85 K - 4.83x slower +0.93 ms
delete footer-poweredbyico (pr)          0.84 K - 4.90x slower +0.95 ms
delete footer-poweredbyico (main)        0.56 K - 7.40x slower +1.55 ms

Memory usage statistics:

Name                                 Memory usage
do nothing (pr)                         341.23 KB
reverse all children (pr)               608.67 KB - 1.78x memory usage +267.44 KB
reverse all children (main)            1212.55 KB - 3.55x memory usage +871.32 KB
do nothing (main)                       945.16 KB - 2.77x memory usage +603.92 KB
delete footer-poweredbyico (pr)         816.06 KB - 2.39x memory usage +474.83 KB
delete footer-poweredbyico (main)      1419.94 KB - 4.16x memory usage +1078.70 KB

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

##### With input small #####
Name                                        ips        average  deviation         median         99th %
reverse all children (pr)               12.40 K       80.65 μs   ±164.37%       40.63 μs      686.97 μs
do nothing (pr)                         12.26 K       81.55 μs   ±154.68%       30.62 μs      609.80 μs
do nothing (main)                        5.13 K      195.06 μs    ±66.46%      222.88 μs      439.79 μs
delete footer-poweredbyico (pr)          4.42 K      226.28 μs    ±56.23%      261.80 μs      462.57 μs
reverse all children (main)              3.73 K      268.35 μs    ±48.08%      279.34 μs      532.85 μs
delete footer-poweredbyico (main)        2.74 K      364.54 μs    ±31.97%      347.42 μs      640.36 μs

Comparison:
reverse all children (pr)               12.40 K
do nothing (pr)                         12.26 K - 1.01x slower +0.90 μs
do nothing (main)                        5.13 K - 2.42x slower +114.41 μs
delete footer-poweredbyico (pr)          4.42 K - 2.81x slower +145.63 μs
reverse all children (main)              3.73 K - 3.33x slower +187.70 μs
delete footer-poweredbyico (main)        2.74 K - 4.52x slower +283.90 μs

Memory usage statistics:

Name                                 Memory usage
reverse all children (pr)               125.11 KB
do nothing (pr)                          69.08 KB - 0.55x memory usage -56.03125 KB
do nothing (main)                       191.57 KB - 1.53x memory usage +66.46 KB
delete footer-poweredbyico (pr)         167.14 KB - 1.34x memory usage +42.03 KB
reverse all children (main)             247.60 KB - 1.98x memory usage +122.49 KB
delete footer-poweredbyico (main)       289.61 KB - 2.31x memory usage +164.50 KB

[philss]

Thank you! 💜 🚀