Compatibility issue with WordPress 5.3

[alimuzzaman]

The stateless mode has a problem with the new WordPress v 5.3.

The full-size image gets uploaded to GCS before generating the thumbnails.
So thumbnails don't get generated on Stateless mode.

[alimuzzaman]

wp_update_attachment_metadata is called here in wp_create_image_subsizes
wp-admin/includes/image.php#L324

Before generating thumbnails in _wp_make_subsizes wp-admin/includes/image.php#L341

In stateless mode, the full-size image is removed from the server in wp_create_image_subsizes function. So later in _wp_make_subsizes function can't find the full size image.

wp_update_attachment_metadata is called multiple times (once for each image size) in wp-admin/includes/image.php#L421

[antonkorotkov]

@alimuzzaman Does it look possible to change the logic for the WordPress starting 5.3 and up? The only thing that comes on mind right now is to remove the original image later so that _wp_make_subsizes can get it.

I see that _wp_make_subsizes runs wp_update_attachment_metadata as well https://github.com/WordPress/WordPress/blob/5.3-branch/wp-admin/includes/image.php#L430 Maybe we can use this too somehow?

Basically, we need to rethink the Stateless Mode in WP 5.3. Don't be afraid to change the logic drastically if needed. This is the only way to keep things updated with the evolving WP.

[alimuzzaman]

Possible way to handle:

1. On the first call from wp_create_image_subsizes $metadata[ 'sizes' ] array is empty.
   What if we don't full size image if sizes array is empty!

2. We can use "intermediate_image_sizes_advanced" filter to indicate that we can now delete image. We will only delete image from server after this filter is fired.

It may possible that some image/file could be left on server.

[antonkorotkov]

Yeah, I meant something like this.

[alimuzzaman]

@antonkorotkov Code review, please.
https://github.com/wpCloud/wp-stateless/compare/2ed064c38c4cbe5a6b67bf2afd92260866a828d7...develop-alim?expand=1

[alimuzzaman]

We have performance issue because of:

wp_update_attachment_metadata is called multiple times (once for each image size) in wp-admin/includes/image.php#L421

[09-Nov-2019 18:54:26 UTC] Media Insert: rabbit.ci/2019/11/008dadf4-alim.jpg
[09-Nov-2019 18:54:30 UTC] Media Insert: rabbit.ci/2019/11/008dadf4-alim-300x225.jpg

[09-Nov-2019 18:54:31 UTC] Media Insert: rabbit.ci/2019/11/008dadf4-alim-300x225.jpg
[09-Nov-2019 18:54:32 UTC] Media Insert: rabbit.ci/2019/11/008dadf4-alim-150x150.jpg

[09-Nov-2019 18:54:34 UTC] Media Insert: rabbit.ci/2019/11/008dadf4-alim-300x225.jpg
[09-Nov-2019 18:54:35 UTC] Media Insert: rabbit.ci/2019/11/008dadf4-alim-150x150.jpg
[09-Nov-2019 18:54:36 UTC] Media Insert: rabbit.ci/2019/11/008dadf4-alim-768x576.jpg

[09-Nov-2019 18:54:38 UTC] Media Insert: rabbit.ci/2019/11/008dadf4-alim-300x225.jpg
[09-Nov-2019 18:54:39 UTC] Media Insert: rabbit.ci/2019/11/008dadf4-alim-150x150.jpg
[09-Nov-2019 18:54:40 UTC] Media Insert: rabbit.ci/2019/11/008dadf4-alim-768x576.jpg
[09-Nov-2019 18:54:43 UTC] Media Insert: rabbit.ci/2019/11/008dadf4-alim-825x510.jpg

[alimuzzaman]

WP Stateless is now compatible with WordPress 5.3.