Introduce the transient files engine #42877

Konamiman · 2023-12-15T16:14:42Z

Changes proposed in this Pull Request:

This pull request introduces a transient files engine intended for registering files that have an expiration date and can be served via a public, unauthenticated HTTP URL. Initially, the only mechanism provided to create these files is providing the raw contents of the file via a input string; but additional mechanisms could be added in the future, such as directly providing the path of an existing file.

See the README file and the documentation comments in the TransientFilesEngine class for all the nitty-gritty details.

This pull request is a simplified version of #41055.

How to test the changes in this Pull Request:

Testing the code API

Run the following:

wp eval "echo wc_get_container()->get(\Automattic\WooCommerce\Internal\TransientFiles\TransientFilesEngine::class)->create_transient_file('foobar', '2024-01-01');"

You'll get a file name whose first 6 digits is the expiration date encoded in hexadecimal (so 7e8 1 01).

Run the following to see the exact physical path of the generated file, where <file name> is the result from the previous call:

wp eval "echo wc_get_container()->get(\Automattic\WooCommerce\Internal\TransientFiles\TransientFilesEngine::class)->get_transient_file_path('<file name>');"

You should have got <WordPress directory>/wp-content/uploads/woocommerce_transient_files/2024-01-01/<file name minus expiration date prefix>. Verify that the file actually exists and it contains the string foobar.

Run the following to delete the generated file:

wp eval "var_export(wc_get_container()->get(\Automattic\WooCommerce\Internal\TransientFiles\TransientFilesEngine::class)->delete_transient_file('<file name>'));"

You'll get true and the file (and also the 2024-01-01 directory) will have disappeared. If you repeat the call you'll get false.

Testing the expired files deletion

To easily test the expired files deletion mechanism we need to be able to create transient files that have already expired. This is not possible out of the box, but can be achieved easily by manually altering the created directory name. So go ahead, create 10 files by repeating step 1 as many times and then rename the 2024-01-01 directory to 2023-01-01 (and now if you wanted to actually locate these files by using get_transient_file_path you'd have to change the first digits of the expiration date prefix from 7e8 to 7e7 in the passed file name).

Now run the following:

wp eval "var_export(wc_get_container()->get(\Automattic\WooCommerce\Internal\TransientFiles\TransientFilesEngine::class)->delete_expired_files(7));"

The result will be:

array (
  'deleted_count' => 7,
  'files_remain' => true,
)

and there will be only 3 files remaining in the 2023-01-01 directory.

Running the same command again will yield the following:

array (
  'deleted_count' => 3,
  'files_remain' => false,
)

and the 2023-01-01 directory will have disappeared.

You can also try the scheduled action by going to WooCommerce - Status - Tools and re-scheduling the cleanup:

By rescheduling the cleanup the action will be scheduled to keep running immediately as long as there's still data to delete, and then every 24h. You can change that interval with a filter, e.g. every 10 seconds:

add_filter('woocommerce_delete_expired_transient_files_interval', fn($interval) => 10);

Note however that the scheduled action deletes 1000 files every time, so for testing you'll need to either create as many transient files or tweak the code to use a smaller batch (pass the batch size to the delete_expired_files call in TransientFilesEngine::handle_expired_files_cleanup_action).

Testing the HTTP endpoint

Generate a transient file by repeating step 1 and verify that you can access the rendered file in your browser (even from an incognito window) or using any tool able to perform HTTP requests (replace <filename> with the file name that you get from create_transient_file): http://localhost/wc/file/transient/<filename>.

If you rename the folder to 2023-01-01 and try to access the file replacing 7e8 with 7e7 at the beginning of its name, you'll get a 404 error, since the endpoint doesn't serve files that have expired (but you can still get the file path with get_transient_file_path).

Changelog entry

Automatically create a changelog entry from the details below.

Significance

Patch
Minor
Major

Type

Fix - Fixes an existing bug
Add - Adds functionality
Update - Update existing functionality
Dev - Development related task
Tweak - A minor adjustment to the codebase
Performance - Address performance issues
Enhancement - Improvement to existing functionality

Message

Comment

Also add a migration to create the base directory for transient files at WooCommerce install time.

github-actions · 2023-12-15T16:17:25Z

Hi @coreymckrill,

Apart from reviewing the code changes, please make sure to review the testing instructions as well.

You can follow this guide to find out what good testing instructions should look like:
https://github.com/woocommerce/woocommerce/wiki/Writing-high-quality-testing-instructions

github-actions · 2023-12-15T16:38:43Z

Test Results Summary

Commit SHA: 131bd3b

Test 🧪	Passed ✅	Failed 🚨	Broken 🚧	Skipped ⏭️	Unknown ❔	Total 📊	Duration ⏱️
API Tests	259	0	0	2	0	261	0m 37s
E2E Tests	258	0	0	3	0	261	15m 50s

To view the full API test report, click here.
To view the full E2E test report, click here.
To view all test reports, visit the WooCommerce Test Reports Dashboard.

coreymckrill

👍 Overall this looks really good! Clear testing instructions, and everything worked as described. I left a few wording suggestions and a couple of minor questions to discuss.

coreymckrill · 2023-12-18T19:06:41Z

plugins/woocommerce/includes/class-woocommerce.php

 		$container->get( FeaturesController::class );
 		$container->get( WebhookUtil::class );
 		$container->get( Marketplace::class );
+		$container->get(\Automattic\WooCommerce\Utilities\TimeUtil::class);


Maybe worth adding a use statement at the top so you don't have to include the full namespace here? It would be more consistent with the rest of the classes in this list.

coreymckrill · 2023-12-18T19:15:24Z