Routing: Add DocumentUrlAliasService for optimized URL alias lookups (closes #21383)

[AndyButland]

Description

This PR addresses the concern raised in #21383 (and also indirectly the cause of #21205), which is that the "content finder by URL alias" that Umbraco ships with does a call to .Descendents() to try to find a document that has the umbracoUrlAlias configured. It will be called when content isn't matched through normal routing, and exit when it find a match.

In doing so though it'll load any content not currently held in memory via the hybrid cache from the database. And so if not finding a match, this will be all documents - thus negating the benefit of not having to load all documents into memory for large websites.

To address this is seems to make sense to do something similar to what we do for URL segments, which are all loaded upfront and cached, for URL aliases.

This PR introduces that - an analogous database table, migration, cache, repository and service for URL aliases.

Change Summary

This PR introduces DocumentUrlAliasService to optimize the performance of ContentFinderByUrlAlias. Previously, finding content by URL alias required traversing the entire content tree on every request, which was extremely slow on large sites.

Key changes:

• New DocumentUrlAliasService - In-memory cache for URL aliases with O(1) lookups
• New database table umbracoDocumentUrlAlias - Persists aliases with optimized indexes
• Updated ContentFinderByUrlAlias - Uses the new service instead of tree traversal
• Cache synchronization - Integrated with ContentCacheRefresher for automatic updates

Testing

Unit and integration tests have been added under ContentFinderByUrlAlias and DocumentUrlAliasService respectively.

Manual testing carried out and for review includes:

• Running Umbraco and ensuring that the umbracoDocumentUrlAlias table is correctly created.
• Any existing documents with an umbracoUrlAlias property is loaded into the database, with one record created per alias (multiple aliases in this property can be added as comma delimited).
• Add and update of documents to add and clear the umbracoUrlAlias property correctly updates the database table.
• Delete of document and language clears records from the table.
• An aliased page is found by the content finder.
• A set up with root domains return the correct document when using an alias (i.e. two documents, under two roots with domains associated, can have the same alias - and if so, when using the alias under a given domain, the expected document should be routed).
  • Similarly an alias for a document requested under a different domain shouldn't be routed.

Known Potential Issues

• I've noted that each alias recorded in the database is recorded for all languages, even if the document itself is invariant. This seems wasteful of storage, but on the other hand it handles cases where the default language is changed or the document is changed from being invariant to variant or vice versa. This same is true for the existing document URL service, and so we need to consider this in a separate discussion and update (or not) for both services.
• We don't have a means of triggering a rebuild of the database cache for aliases (other than fiddling it by updating the value held at select value from umbracoKeyValue where [key] = 'UmbracoUrlAliasGeneration' and restarting Umbraco). Seems this would be a good option to have for an administrator, either as part of, or as a separate but related action, triggered from Settings > Published Status > Rebuild Database Cache. Again, this is the same situation for the document URL service database table, and so we should consider adding this for both services.

[Copilot]

Pull request overview

This PR introduces DocumentUrlAliasService to optimize URL alias lookups in Umbraco CMS. Previously, finding content by URL alias required traversing the entire content tree on every request. The new implementation uses an in-memory cache with O(1) dictionary lookups backed by a new umbracoDocumentUrlAlias database table.

Changes:

• Adds DocumentUrlAliasService with in-memory caching for fast URL alias resolution
• Creates new database table umbracoDocumentUrlAlias with optimized indexes for alias lookups
• Updates ContentFinderByUrlAlias to use the new service instead of tree traversal
• Integrates with ContentCacheRefresher for automatic cache synchronization on content changes

Reviewed changes

Copilot reviewed 21 out of 21 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
DocumentUrlAliasService.cs	Core service implementation with concurrent dictionaries for caching and scope-based deferred updates
IDocumentUrlAliasService.cs	Service interface defining alias lookup and management operations
DocumentUrlAliasServiceInitializerNotificationHandler.cs	Handles service initialization on application startup
DocumentUrlAliasRepository.cs	Repository implementation for database operations with optimized SQL queries
IDocumentUrlAliasRepository.cs	Repository interface and raw data model
DocumentUrlAliasDto.cs	DTO with unique and lookup indexes for performance
PublishedDocumentUrlAlias.cs	Model class for published document URL aliases
AddDocumentUrlAlias.cs	Migration to add the new table and lock record
ContentFinderByUrlAlias.cs	Updated to use service instead of tree traversal, with backward-compatible constructors
ContentCacheRefresher.cs	Integration for cache synchronization on content changes
ContentFinderByUrlAliasTests.cs	14 unit tests covering various alias lookup scenarios
DocumentUrlAliasServiceTests.cs	27 integration tests covering CRUD operations and edge cases
LanguageRepository.cs	Cleanup aliases when language is deleted
DocumentRepository.cs	Cleanup aliases when document is deleted
UmbracoPlan.cs	Registers the migration in the upgrade plan
DatabaseSchemaCreator.cs	Includes DTO in schema creation
DatabaseDataCreator.cs	Adds lock record during installation
UmbracoBuilder.Repositories.cs	Registers repository in DI container
UmbracoBuilder.cs	Registers service and initialization handler in DI container
Constants-Locks.cs	Adds DocumentUrlAliases lock constant
Constants-DatabaseSchema.cs	Adds DocumentUrlAlias table constant

[umbracocommunity]

This pull request has been mentioned on Umbraco community forum. There might be relevant details there:

https://forum.umbraco.com/t/error-in-documenturlalias-repository-when-upgrading-from-17-1-to-17-2-x/7578/4