defmodule PlugRange do
@behaviour Plug
@allowed_methods ~w(GET HEAD)
import Plug.Conn
def init(options) do
options
end
def call(conn, _opts) do
if (Enum.empty?(Plug.Conn.get_req_header(conn, "range"))) do
conn
else
file_path = "priv/static" <> conn.request_path
if File.exists? file_path do
stats = File.stat! file_path
filesize = stats.size
req = Regex.run(~r/bytes=([0-9]+)?-([0-9]+)?/, conn |> Plug.Conn.get_req_header("range") |> List.first)
case req do
p when p == nil or ["bytes=", "", "-"] == p or length(p) < 2 ->
send_bad_range conn
_ ->
{req_start, _} =
if (req |> Enum.at(1) == "") do
{-1, :end_file}
else
req |> Enum.at(1) |> Integer.parse
end
{req_end, _} = req |> Enum.at(2, filesize |> to_string) |> Integer.parse
if (req_start == 0 && req_end == filesize) do
conn
else
{req_start, length} = case req_start do
-1 -> {filesize - req_end, req_end}
p -> {req_start, req_end - req_start + 1}
end
file_end = ( filesize - 2) |> to_string
conn
|> Plug.Conn.put_resp_header("accept-ranges", "bytes")
|> Plug.Conn.put_resp_header("content-range", "bytes #{req_start}-#{req_end}/#{filesize}")
|> Plug.Conn.send_file(206, file_path, req_start, length)
|> Plug.Conn.halt
end
end
end
end
end
def send_bad_range(conn) do
conn
|> Plug.Conn.put_resp_content_type("text/html")
|> Plug.Conn.put_resp_header("content-length", bad_range |> String.length |> to_string)
|> Plug.Conn.send_resp(416, bad_range)
|> Plug.Conn.halt
end
def bad_range do
"""
416 Requested Range Not Satisfiable
416 Requested Range Not Satisfiable
cowboy
"""
end
end