Streaming Size Check

stream_test.ex

defmodule StreamTest do
  use GenServer

  def start_link(opts \\ []) do
    GenServer.start_link(__MODULE__, :ok, opts)
  end

  def init(:ok) do
    #url = "http://www.thinkbroadband.com/download/"
    #url = "http://download.thinkbroadband.com/5MB.zip"
    #url = "http://download.thinkbroadband.com/1GB.zip"
    poison = HTTPoison.get!(url, %{}, [stream_to: self()])
    {:ok, %{file: "", poison: poison}}
  end

  def handle_info(msg, %{ file: file } = state) do
    updated_state = state
    case msg do
      %HTTPoison.AsyncStatus{} ->
        0
      %HTTPoison.AsyncHeaders{} ->
        content_length = Enum.find_value(msg.headers, fn(map) ->  if Enum.member?(Tuple.to_list(map), "Content-Length"), do: elem(map, 1) end)
        if is_nil(content_length) do
          0
        else
          {int, _} =  Integer.parse(content_length)
          int
        end
      %HTTPoison.AsyncChunk{} ->
        updated_state = %{ state | file: file <> msg.chunk}
        byte_size(updated_state.file)
      %HTTPoison.AsyncEnd{} ->
        byte_size(file)
      _ ->
        IO.inspect {:handle_info, msg}
        0
    end |> size_check
    {:noreply, updated_state}
  end

  defp size_check(size) when size <= 10_000_000,  do: IO.puts "Size: #{size}"
  defp size_check(size) when size > 10_000_000,  do: GenServer.stop(self())
end

{:ok, pid} = StreamTest.start_link