Refactor the query to detect unattached media

The previous one was going 💥 in production

Signed-off-by: Thomas Citharel <tcit@tcit.fr>
This commit is contained in:
Thomas Citharel 2021-07-21 19:02:20 +02:00
parent 71f50b35b6
commit db1649ded8
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@ -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