[wp-trac] [WordPress Trac] #61383: Add new filter to attachment_url_to_postid() for short circuit

[WordPress Trac]

#61383: Add new filter to attachment_url_to_postid() for short circuit
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 Reporter:  apermo       |      Owner:  (none)
     Type:  enhancement  |     Status:  new
 Priority:  normal       |  Milestone:  Awaiting Review
Component:  Media        |    Version:
 Severity:  normal       |   Keywords:  has-patch
  Focuses:               |
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 The function `attachment_url_to_postid()` will receive a relative url and
 then use the query following query to get the corresponding `post_id` for
 the attachment.

 `SELECT post_id, meta_value FROM wp_postmeta WHERE meta_key =
 '_wp_attached_file' AND meta_value = '2024/06/my-image.jpg'`

 On large installations, this will be slow, resulting in long delays upon
 saving. In my example we are talking about 4s per query, since the
 installation has 500k images in the database. And if a post has a gallery,
 this can result in save times above 30s. So even for less extreme sizes
 this query will result in long wait times for editors, if they save posts
 with lots of images.

 Adding a new column to wp_post or a new table to core is unlikely, since
 the default behavior works fine for standard installations.

 So in my case I want to add a custom table, to speed up my installation.
 And while it currently already is possible to filter the query before it
 is executed using the filter `query` this requires a to check all incoming
 queries, if it possibly is one those that I want to replace.

 This is why I propose to add a filter at the beginning of the function,
 which allows to short circuit the function if anyone wants to use a custom
 method.

 As already mentioned, I've checked the following alternatives for my
 particular site and I think adding the filter will add value here.

 * Using `query` deeper inside the function. Will work, but is not ideal
 since you need to check all queries, and on top, it will only allow you to
 use the database as source, so if you'd have a different method of getting
 the result, it would require you to fake a result, or use the filter at
 the end of the function, after you already did the query.
 * Adding an index to the meta_value column. This speeded up the query from
 4s to 20ms in my case, but I do not dare to do so on a production system,
 since I have no idea what side effects this will have.
 * Overriding the function will not work, since the function does not come
 wrapped in a `if ( function_exists() )` and the function is used twice in
 core, as well as in Yoast SEO and ACF.

 Which comes to the conclusion, by adding the attached filter, it will make
 it easier to allow custom methods of retrieving the `post_id` faster for
 special setups.

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Ticket URL: <https://core.trac.wordpress.org/ticket/61383>
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