Fixed behaviour on database cache rebuild to update only for requested content types

[AndyButland]

Prerequisites

• I have added steps to test this contribution in the description below

Resolves: #19902

Description

The linked PR shows that saving document types is very slow when an installation has a lot of members. On the face of it this shouldn't have a significant impact.

I found it's happening as the logic in rebuilding the database cache doesn't look to be correct. According to the code comments on the interface for the parameters for each of the three types or content type, we should consider "null" as "don't do anything with this content type and "empty" to be to "rebuild everything for the content type", e.g.:

    /// <param name="memberTypeIds">
    ///     If not null will process content for the matching members types, if empty will process all
    ///     members.
    /// </param>

In the implementation though this was mixed up, and we were rebuilding everything on null inputs too.

Arguably this is behaviourally breaking but seems like this is a bug to fix - it resolves the issue and now the behaviour matches with the XML header comments on the interface.

I also found and fixed another bug where we were passing media type keys as document type keys in the MediaCacheService. Likely didn't previously cause a problem as media would be fully rebuilt anyway due to the incorrect behaviour, but now that's amended it's important these are passed correctly too.

Testing

You can test with a breakpoint in DatabaseCacheRepository.Rebuild() and verifying that with these changes in place, we don't rebuild the member or media cache when saving a document type (or other combinations).

[Copilot]

Pull Request Overview

This PR fixes performance issues when saving document types in installations with many members by correcting the database cache rebuild logic. The root cause was that null parameters were incorrectly triggering full cache rebuilds instead of skipping cache updates for unrelated content types.

Key Changes:

• Fixed parameter interpretation in database cache rebuild methods to correctly handle null vs empty collections
• Corrected MediaCacheService to pass media type IDs instead of incorrectly named content type IDs
• Updated DatabaseCacheRebuilder to explicitly pass empty collections instead of relying on default null parameters

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
MediaCacheService.cs	Fixed parameter naming issue where contentTypeIds was passed instead of mediaTypeIds
DatabaseCacheRepository.cs	Corrected null vs empty collection handling in rebuild methods to match interface documentation
DatabaseCacheRebuilder.cs	Updated to explicitly pass empty collections instead of using default null parameters

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[skttl]

I tested it with my Clean Starter Kit test site, and a document type is now fast again.

The member type is still slow though, but I guess that is expected. (I have also created 20.000 article nodes, and the article document type is similarly slow to save - not as much, but noticeably)

[Zeegaan]

Looks good to me 🚀

Thanks to @skttl for testing aswell ❤️

[Zeegaan]

@skttl We've done some optimizations around saving large amounts of content, but I guess theres still room for improvement 🤔