From db1649ded80fb3de625b929d77694b7b54856703 Mon Sep 17 00:00:00 2001
From: Thomas Citharel <tcit@tcit.fr>
Date: Wed, 21 Jul 2021 19:02:20 +0200
Subject: [PATCH] Refactor the query to detect unattached media
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The previous one was going 💥 in production
Signed-off-by: Thomas Citharel <tcit@tcit.fr>
---
lib/service/clean_orphan_media.ex | 44 ++++++++++++++++++++-----------
1 file changed, 28 insertions(+), 16 deletions(-)
diff --git a/lib/service/clean_orphan_media.ex b/lib/service/clean_orphan_media.ex
index 6aa01e3ed..66703d30c 100644
--- a/lib/service/clean_orphan_media.ex
+++ b/lib/service/clean_orphan_media.ex
@@ -33,6 +33,22 @@ defmodule Mobilizon.Service.CleanOrphanMedia do
end
end
+ # Ecto doesn't currently allow us to use exists with a subquery,
+ # so we can't create the union through Ecto
+ # https://github.com/elixir-ecto/ecto/issues/3619
+ @union_query [
+ [from: "events", param: "picture_id"],
+ [from: "events_medias", param: "media_id"],
+ [from: "posts", param: "picture_id"],
+ [from: "posts_medias", param: "media_id"],
+ [from: "comments_medias", param: "media_id"]
+ ]
+ |> Enum.map(fn [from: from, param: param] ->
+ "SELECT 1 FROM #{from} WHERE #{from}.#{param} = m0.id"
+ end)
+ |> Enum.join(" UNION ")
+ |> (&"NOT EXISTS(#{&1})").()
+
@spec find_media(Keyword.t()) :: list(Media.t())
defp find_media(opts) do
default_grace_period =
@@ -41,21 +57,17 @@ defmodule Mobilizon.Service.CleanOrphanMedia do
grace_period = Keyword.get(opts, :grace_period, default_grace_period)
expiration_date = DateTime.add(DateTime.utc_now(), grace_period * -3600)
- Media
- |> where([m], m.inserted_at < ^expiration_date)
- |> join(:inner, [m], a in Actor)
- |> where([_m, a], is_nil(a.domain))
- |> join(:left, [m], e in assoc(m, :events))
- |> join(:left, [m], ep in assoc(m, :event_picture))
- |> join(:left, [m], p in assoc(m, :posts))
- |> join(:left, [m], pp in assoc(m, :posts_picture))
- |> join(:left, [m], c in assoc(m, :comments))
- |> where([_m, _a, e], is_nil(e.id))
- |> where([_m, _a, _e, ep], is_nil(ep.id))
- |> where([_m, _a, _e, _ep, p], is_nil(p.id))
- |> where([_m, _a, _e, _ep, _p, pp], is_nil(pp.id))
- |> where([_m, _a, _e, _ep, _p, _pp, c], is_nil(c.id))
- |> distinct(true)
- |> Repo.all()
+ query =
+ from(m in Media,
+ as: :media,
+ distinct: true,
+ join: a in Actor,
+ on: a.id == m.actor_id,
+ where: is_nil(a.domain),
+ where: m.inserted_at < ^expiration_date,
+ where: fragment(@union_query)
+ )
+
+ Repo.all(query)
end
end