honkoma/lib/pleroma/mime.ex

81 lines
2.3 KiB
Elixir

# Pleroma: A lightweight social networking server
# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
# SPDX-License-Identifier: AGPL-3.0-only
defmodule Pleroma.MIME do
@moduledoc """
Returns the mime-type of a binary and optionally a normalized file-name.
"""
@read_bytes 35
@pool __MODULE__.GenMagicPool
def child_spec(_) do
pool_size = Pleroma.Config.get!([:gen_magic_pool, :size])
name = @pool
%{
id: __MODULE__,
start: {GenMagic.Pool, :start_link, [[name: name, pool_size: pool_size]]},
type: :worker,
restart: :permanent,
shutdown: 500
}
end
@spec file_mime_type(String.t(), String.t()) ::
{:ok, content_type :: String.t(), filename :: String.t()} | {:error, any()} | :error
def file_mime_type(path, filename) do
with {:ok, content_type} <- file_mime_type(path),
filename <- fix_extension(filename, content_type) do
{:ok, content_type, filename}
end
end
@spec file_mime_type(String.t()) :: {:ok, String.t()} | {:error, any()} | :error
def file_mime_type(filename) do
case GenMagic.Pool.perform(@pool, filename) do
{:ok, %GenMagic.Result{mime_type: content_type}} -> {:ok, content_type}
error -> error
end
end
def bin_mime_type(binary, filename) do
with {:ok, content_type} <- bin_mime_type(binary),
filename <- fix_extension(filename, content_type) do
{:ok, content_type, filename}
end
end
@spec bin_mime_type(binary()) :: {:ok, String.t()} | :error
def bin_mime_type(<<head::binary-size(@read_bytes), _::binary>>) do
case GenMagic.Pool.perform(@pool, {:bytes, head}) do
{:ok, %GenMagic.Result{mime_type: content_type}} -> {:ok, content_type}
error -> error
end
end
def bin_mime_type(_), do: :error
defp fix_extension(filename, content_type) do
parts = String.split(filename, ".")
new_filename =
if length(parts) > 1 do
Enum.drop(parts, -1) |> Enum.join(".")
else
Enum.join(parts)
end
cond do
content_type == "application/octet-stream" ->
filename
ext = List.first(MIME.extensions(content_type)) ->
new_filename <> "." <> ext
true ->
Enum.join([new_filename, String.split(content_type, "/") |> List.last()], ".")
end
end
end