+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
defmodule Pleroma.Web.RichMedia.Parser do
- @parsers [
- Pleroma.Web.RichMedia.Parsers.OGP,
- Pleroma.Web.RichMedia.Parsers.TwitterCard,
- Pleroma.Web.RichMedia.Parsers.OEmbed
+ @hackney_options [
+ pool: :media,
+ recv_timeout: 2_000,
+ max_body: 2_000_000,
+ with_body: true
]
+ defp parsers do
+ Pleroma.Config.get([:rich_media, :parsers])
+ end
+
def parse(nil), do: {:error, "No URL provided"}
- if Mix.env() == :test do
+ if Pleroma.Config.get(:env) == :test do
def parse(url), do: parse_url(url)
else
def parse(url) do
- with {:ok, data} <- Cachex.fetch(:rich_media_cache, url, fn _ -> parse_url(url) end) do
- data
- else
- _e ->
- {:error, "Parsing error"}
+ try do
+ Cachex.fetch!(:rich_media_cache, url, fn _ ->
+ {:commit, parse_url(url)}
+ end)
+ |> set_ttl_based_on_image(url)
+ rescue
+ e ->
+ {:error, "Cachex error: #{inspect(e)}"}
end
end
end
+ @doc """
+ Set the rich media cache based on the expiration time of image.
+
+ Adopt behaviour `Pleroma.Web.RichMedia.Parser.TTL`
+
+ ## Example
+
+ defmodule MyModule do
+ @behaviour Pleroma.Web.RichMedia.Parser.TTL
+ def ttl(data, url) do
+ image_url = Map.get(data, :image)
+ # do some parsing in the url and get the ttl of the image
+ # and return ttl is unix time
+ parse_ttl_from_url(image_url)
+ end
+ end
+
+ Define the module in the config
+
+ config :pleroma, :rich_media,
+ ttl_setters: [MyModule]
+ """
+ def set_ttl_based_on_image({:ok, data}, url) do
+ with {:ok, nil} <- Cachex.ttl(:rich_media_cache, url),
+ ttl when is_number(ttl) <- get_ttl_from_image(data, url) do
+ Cachex.expire_at(:rich_media_cache, url, ttl * 1000)
+ {:ok, data}
+ else
+ _ ->
+ {:ok, data}
+ end
+ end
+
+ defp get_ttl_from_image(data, url) do
+ Pleroma.Config.get([:rich_media, :ttl_setters])
+ |> Enum.reduce({:ok, nil}, fn
+ module, {:ok, _ttl} ->
+ module.ttl(data, url)
+
+ _, error ->
+ error
+ end)
+ end
+
defp parse_url(url) do
try do
- {:ok, %Tesla.Env{body: html}} = Pleroma.HTTP.get(url)
+ {:ok, %Tesla.Env{body: html}} = Pleroma.HTTP.get(url, [], adapter: @hackney_options)
- html |> maybe_parse() |> get_parsed_data()
+ html
+ |> parse_html
+ |> maybe_parse()
+ |> Map.put(:url, url)
+ |> clean_parsed_data()
+ |> check_parsed_data()
rescue
- _e ->
- {:error, "Parsing error"}
+ e ->
+ {:error, "Parsing error: #{inspect(e)}"}
end
end
+ defp parse_html(html), do: Floki.parse(html)
+
defp maybe_parse(html) do
- Enum.reduce_while(@parsers, %{}, fn parser, acc ->
+ Enum.reduce_while(parsers(), %{}, fn parser, acc ->
case parser.parse(html, acc) do
{:ok, data} -> {:halt, data}
{:error, _msg} -> {:cont, acc}
end)
end
- defp get_parsed_data(data) when data == %{} do
- {:error, "No metadata found"}
+ defp check_parsed_data(%{title: title} = data)
+ when is_binary(title) and byte_size(title) > 0 do
+ {:ok, data}
+ end
+
+ defp check_parsed_data(data) do
+ {:error, "Found metadata was invalid or incomplete: #{inspect(data)}"}
end
- defp get_parsed_data(data) do
- {:ok, data}
+ defp clean_parsed_data(data) do
+ data
+ |> Enum.reject(fn {key, val} ->
+ with {:ok, _} <- Jason.encode(%{key => val}) do
+ false
+ else
+ _ -> true
+ end
+ end)
+ |> Map.new()
end
end