 2641dcdd15
			
		
	
	
		2641dcdd15
		
	
	
	
	
		
			
			Rebased from #103 Co-authored-by: Tusooa Zhu <tusooa@kazv.moe> Co-authored-by: FloatingGhost <hannah@coffee-and-dreams.uk> Reviewed-on: https://akkoma.dev/AkkomaGang/akkoma/pulls/202
		
			
				
	
	
		
			81 lines
		
	
	
	
		
			2.5 KiB
		
	
	
	
		
			Elixir
		
	
	
	
	
	
			
		
		
	
	
			81 lines
		
	
	
	
		
			2.5 KiB
		
	
	
	
		
			Elixir
		
	
	
	
	
	
| # Pleroma: A lightweight social networking server
 | |
| # Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
 | |
| # SPDX-License-Identifier: AGPL-3.0-only
 | |
| 
 | |
| defmodule Pleroma.Activity.HTML do
 | |
|   alias Pleroma.HTML
 | |
|   alias Pleroma.Object
 | |
| 
 | |
|   @cachex Pleroma.Config.get([:cachex, :provider], Cachex)
 | |
| 
 | |
|   # We store a list of cache keys related to an activity in a
 | |
|   # separate cache, scrubber_management_cache. It has the same
 | |
|   # size as scrubber_cache (see application.ex). Every time we add
 | |
|   # a cache to scrubber_cache, we update scrubber_management_cache.
 | |
|   #
 | |
|   # The most recent write of a certain key in the management cache
 | |
|   # is the same as the most recent write of any record related to that
 | |
|   # key in the main cache.
 | |
|   # Assuming LRW ( https://hexdocs.pm/cachex/Cachex.Policy.LRW.html ),
 | |
|   # this means when the management cache is evicted by cachex, all
 | |
|   # related records in the main cache will also have been evicted.
 | |
| 
 | |
|   defp get_cache_keys_for(activity_id) do
 | |
|     with {:ok, list} when is_list(list) <- @cachex.get(:scrubber_management_cache, activity_id) do
 | |
|       list
 | |
|     else
 | |
|       _ -> []
 | |
|     end
 | |
|   end
 | |
| 
 | |
|   defp add_cache_key_for(activity_id, additional_key) do
 | |
|     current = get_cache_keys_for(activity_id)
 | |
| 
 | |
|     unless additional_key in current do
 | |
|       @cachex.put(:scrubber_management_cache, activity_id, [additional_key | current])
 | |
|     end
 | |
|   end
 | |
| 
 | |
|   def invalidate_cache_for(activity_id) do
 | |
|     keys = get_cache_keys_for(activity_id)
 | |
|     Enum.map(keys, &@cachex.del(:scrubber_cache, &1))
 | |
|     @cachex.del(:scrubber_management_cache, activity_id)
 | |
|   end
 | |
| 
 | |
|   def get_cached_scrubbed_html_for_activity(
 | |
|         content,
 | |
|         scrubbers,
 | |
|         activity,
 | |
|         key \\ "",
 | |
|         callback \\ fn x -> x end
 | |
|       ) do
 | |
|     key = "#{key}#{generate_scrubber_signature(scrubbers)}|#{activity.id}"
 | |
| 
 | |
|     @cachex.fetch!(:scrubber_cache, key, fn _key ->
 | |
|       object = Object.normalize(activity, fetch: false)
 | |
| 
 | |
|       add_cache_key_for(activity.id, key)
 | |
|       HTML.ensure_scrubbed_html(content, scrubbers, object.data["fake"] || false, callback)
 | |
|     end)
 | |
|   end
 | |
| 
 | |
|   def get_cached_stripped_html_for_activity(content, activity, key) do
 | |
|     get_cached_scrubbed_html_for_activity(
 | |
|       content,
 | |
|       FastSanitize.Sanitizer.StripTags,
 | |
|       activity,
 | |
|       key,
 | |
|       &HtmlEntities.decode/1
 | |
|     )
 | |
|   end
 | |
| 
 | |
|   defp generate_scrubber_signature(scrubber) when is_atom(scrubber) do
 | |
|     generate_scrubber_signature([scrubber])
 | |
|   end
 | |
| 
 | |
|   defp generate_scrubber_signature(scrubbers) do
 | |
|     Enum.reduce(scrubbers, "", fn scrubber, signature ->
 | |
|       "#{signature}#{to_string(scrubber)}"
 | |
|     end)
 | |
|   end
 | |
| end
 |