Orb Mime Type

Mix.install([
  :orb,
  {:wasmex, "~> 0.8.3"},
  {:mime, "~> 2.0.5"},
  {:kino, "~> 0.12.0"}
])

Define our Mime Type module using Orb

defmodule MimeType do
  use Orb

  Memory.pages(1)

  defw(txt, I32.UnsafePointer, do: MIME.type("txt"))
  defw(json, I32.UnsafePointer, do: MIME.type("json"))
  defw(html, I32.UnsafePointer, do: MIME.type("html"))
  defw(css, I32.UnsafePointer, do: MIME.type("css"))
  defw(wasm, I32.UnsafePointer, do: MIME.type("wasm"))
  defw(epub, I32.UnsafePointer, do: MIME.type("epub"))
  defw(rss, I32.UnsafePointer, do: MIME.type("rss"))
  defw(atom, I32.UnsafePointer, do: MIME.type("atom"))
  defw(csv, I32.UnsafePointer, do: MIME.type("csv"))
  defw(woff2, I32.UnsafePointer, do: MIME.type("woff2"))
  defw(pdf, I32.UnsafePointer, do: MIME.type("pdf"))
  defw(js, I32.UnsafePointer, do: "application/javascript")
  defw(xml, I32.UnsafePointer, do: "application/xml")
  defw(sqlite, I32.UnsafePointer, do: "application/vnd.sqlite3")
end

We can run the WebAssembly module in Elixir using Wasmex

file_extension = "html"

{:ok, pid} = Wasmex.start_link(%{bytes: Orb.to_wat(MimeType)})
{:ok, memory} = Wasmex.memory(pid)
{:ok, store} = Wasmex.store(pid)
byte_count = Wasmex.Memory.size(store, memory)
bytes = Wasmex.Memory.read_binary(store, memory, 0, byte_count)

case Wasmex.call_function(pid, file_extension, []) do
  {:ok, [str_ptr]} ->
    slice = binary_slice(bytes, str_ptr..-1//1)

    for(<>, do: chunk)
    |> Enum.take_while(fn c -> c != 0 end)
    |> List.to_string()

  {:error, _} ->
    nil
end