1 # Pleroma: A lightweight social networking server
2 # Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
3 # SPDX-License-Identifier: AGPL-3.0-only
5 defmodule Pleroma.Web.Plugs.Cache do
7 Caches successful GET responses.
9 To enable the cache add the plug to a router pipeline or controller:
11 plug(Pleroma.Web.Plugs.Cache)
15 To configure the plug you need to pass settings as the second argument to the `plug/2` macro:
17 plug(Pleroma.Web.Plugs.Cache, [ttl: nil, query_params: true])
21 - `ttl`: An expiration time (time-to-live). This value should be in milliseconds or `nil` to disable expiration. Defaults to `nil`.
22 - `query_params`: Take URL query string into account (`true`), ignore it (`false`) or limit to specific params only (list). Defaults to `true`.
23 - `tracking_fun`: A function that is called on successful responses, no matter if the request is cached or not. It should accept a conn as the first argument and the value assigned to `tracking_fun_data` as the second.
25 Additionally, you can overwrite the TTL inside a controller action by assigning `cache_ttl` to the connection struct:
27 def index(conn, _params) do
28 ttl = 60_000 # one minute
31 |> assign(:cache_ttl, ttl)
32 |> render("index.html")
37 import Phoenix.Controller, only: [current_path: 1, json: 2]
42 @defaults %{ttl: nil, query_params: true}
44 @cachex Pleroma.Config.get([:cachex, :provider], Cachex)
47 def init([]), do: @defaults
51 Map.merge(@defaults, opts)
55 def call(%{method: "GET"} = conn, opts) do
56 key = cache_key(conn, opts)
58 case @cachex.get(:web_resp_cache, key) do
60 cache_resp(conn, opts)
62 {:ok, {content_type, body, tracking_fun_data}} ->
63 conn = opts.tracking_fun.(conn, tracking_fun_data)
65 send_cached(conn, {content_type, body})
68 send_cached(conn, record)
70 {atom, message} when atom in [:ignore, :error] ->
71 render_error(conn, message)
75 def call(conn, _), do: conn
77 # full path including query params
78 defp cache_key(conn, %{query_params: true}), do: current_path(conn)
80 # request path without query params
81 defp cache_key(conn, %{query_params: false}), do: conn.request_path
83 # request path with specific query params
84 defp cache_key(conn, %{query_params: query_params}) when is_list(query_params) do
87 |> Map.take(query_params)
90 conn.request_path <> "?" <> query_string
93 defp cache_resp(conn, opts) do
94 register_before_send(conn, fn
95 %{status: 200, resp_body: body} = conn ->
96 ttl = Map.get(conn.assigns, :cache_ttl, opts.ttl)
97 key = cache_key(conn, opts)
98 content_type = content_type(conn)
100 should_cache = not Map.get(conn.assigns, :skip_cache, false)
103 unless opts[:tracking_fun] do
105 @cachex.put(:web_resp_cache, key, {content_type, body}, ttl: ttl)
110 tracking_fun_data = Map.get(conn.assigns, :tracking_fun_data, nil)
113 @cachex.put(:web_resp_cache, key, {content_type, body, tracking_fun_data}, ttl: ttl)
116 opts.tracking_fun.(conn, tracking_fun_data)
119 put_resp_header(conn, "x-cache", "MISS from Pleroma")
126 defp content_type(conn) do
128 |> Plug.Conn.get_resp_header("content-type")
132 defp send_cached(conn, {content_type, body}) do
134 |> put_resp_content_type(content_type, nil)
135 |> put_resp_header("x-cache", "HIT from Pleroma")
136 |> send_resp(:ok, body)
140 defp render_error(conn, message) do
142 |> put_status(:internal_server_error)
143 |> json(%{error: message})