reduplicate

dup_bench.exs

Benchfella.start duration: 1.0

defmodule StringDuplicateBench do
  use Benchfella

  Enum.each([100, 1000, 10000, 100000], fn n ->
    @str "1234567890"
    @n n

    bench "binary copy #{n}" do
      :binary.copy(@str, @n)
    end

    bench "strdup #{n}" do
      strdup(@str, @n)
    end
  end)

  # The same idea as in fast exponentiation by squaring is used here
  
  def strdup(_, 0), do: ""
  def strdup(str, 1), do: str

  def strdup(str, n) when rem(n, 2) == 0 do
    tmp = strdup(str, div(n, 2))
    tmp <> tmp
  end

  def strdup(str, n) do
    str <> strdup(str, n-1)
  end
end

just_nox

StringDuplicateBench.strdup nox erlang 100:        1000000   1.42 µs/op
StringDuplicateBench.strdup nox core 100:          1000000   1.46 µs/op
StringDuplicateBench.strdup nox core 1000:         1000000   2.23 µs/op
StringDuplicateBench.strdup nox erlang 1000:       1000000   2.50 µs/op
StringDuplicateBench.strdup nox core 10000:         100000   12.12 µs/op
StringDuplicateBench.strdup nox erlang 10000:       100000   15.03 µs/op
StringDuplicateBench.strdup nox erlang 100000:       10000   121.60 µs/op
StringDuplicateBench.strdup nox core 100000:          5000   450.42 µs/op
StringDuplicateBench.strdup nox core 1000000:          500   5122.71 µs/op
StringDuplicateBench.strdup nox erlang 1000000:        500   5712.28 µs/op

nox_bench.exs

Benchfella.start duration: 1.0

defmodule StringDuplicateBench do
  use Benchfella

  Enum.each([100, 1000, 10000, 100000], fn n ->
    @str "1234567890"
    @n n

    bench "binary copy #{n}" do
      :binary.copy(@str, @n)
    end

    bench "strdup true_droid #{n}" do
      :t.true_droid(@str, @n)
    end

    bench "strdup nox erlang #{n}" do
      :t.nox_erlang(@str, @n)
    end

    bench "strdup nox core #{n}" do
      :t2.nox_core(@str, @n)
    end
  end)
end

nox_results

StringDuplicateBench.binary copy 100:            10000000   0.72 µs/op
StringDuplicateBench.strdup nox erlang 100:       1000000   1.42 µs/op
StringDuplicateBench.strdup nox core 100:         1000000   1.47 µs/op
StringDuplicateBench.strdup true_droid 100:       1000000   1.71 µs/op
StringDuplicateBench.strdup nox core 1000:        1000000   2.25 µs/op
StringDuplicateBench.strdup nox erlang 1000:      1000000   2.53 µs/op
StringDuplicateBench.strdup true_droid 1000:       500000   3.17 µs/op
StringDuplicateBench.binary copy 1000:             500000   5.54 µs/op
StringDuplicateBench.strdup true_droid 10000:      100000   10.08 µs/op
StringDuplicateBench.strdup nox core 10000:        100000   12.46 µs/op
StringDuplicateBench.strdup nox erlang 10000:      100000   15.87 µs/op
StringDuplicateBench.binary copy 10000:             50000   54.38 µs/op
StringDuplicateBench.strdup true_droid 100000:      20000   90.44 µs/op
StringDuplicateBench.strdup nox erlang 100000:      10000   120.18 µs/op
StringDuplicateBench.strdup nox core 100000:         5000   450.04 µs/op
StringDuplicateBench.binary copy 100000:             5000   543.66 µs/op

results

StringDuplicateBench.binary copy 100:      10000000   0.71 µs/op
StringDuplicateBench.strdup 100:            1000000   1.69 µs/op
StringDuplicateBench.strdup 1000:            500000   3.48 µs/op
StringDuplicateBench.binary copy 1000:       500000   5.41 µs/op
StringDuplicateBench.strdup 10000:           100000   11.29 µs/op
StringDuplicateBench.binary copy 10000:       50000   54.60 µs/op
StringDuplicateBench.strdup 100000:           20000   88.69 µs/op
StringDuplicateBench.binary copy 100000:       5000   546.27 µs/op