Umbraco-CMS/thoughts/shared/handoffs/general/2025-12-20_00-38-15_contentservice-performance-review.md

date, researcher, git_commit, branch, repository, topic, tags, status, last_updated, last_updated_by, type

date	researcher	git_commit	branch	repository	topic	tags	status	last_updated	last_updated_by	type
2025-12-20T00:38:15+00:00	Claude	f4a01ed50d	refactor/ContentService	Umbraco-CMS	ContentService Refactoring Performance Review	implementation performance refactoring contentservice	completed	2025-12-20	Claude	implementation_strategy

Handoff: ContentService Performance Review for Refactoring Design

Task(s)

Brainstorming session to review the ContentService refactoring design for performance improvements across four areas:

Area	Status	Decision
1. Database Query Efficiency	Completed	Batch lookups (4 steps)
2. Memory Allocation Patterns	Completed	Aggressive, incremental (7 steps)
3. Concurrency & Locking	Completed	Moderate (4 steps)
4. Caching Strategies	Completed	Moderate (4 steps)

Working from the design document at docs/plans/2025-12-19-contentservice-refactor-design.md.

Critical References

1. docs/plans/2025-12-19-contentservice-refactor-design.md - The refactoring design being reviewed
2. src/Umbraco.Core/Services/ContentService.cs - Current ~3800 line implementation being refactored
3. src/Umbraco.Core/Services/IContentService.cs - Interface contract

Recent changes

No code changes made. This is a design review/brainstorming session.

Learnings

Database Query Efficiency Issues Identified

1. N+1 Query in GetContentSchedulesByIds (ContentService.cs:1025-1049): Loop calling _idKeyMap.GetIdForKey for each key individually instead of batch lookup.

2. Multiple repository calls in CommitDocumentChangesInternal (ContentService.cs:1461+): Separate calls for GetContentSchedule, Save, and PersistContentSchedule within same scope.

3. Repeated GetById calls: IsPathPublishable (line 1070), GetAncestors (line 792) make multiple single-item lookups.

Decision Made: User approved Option 1 (Batch lookups) approach:

• Add batch methods like GetSchedulesByContentIds(int[] ids), ArePathsPublished(int[] contentIds), GetParents(int[] contentIds)
• Fix N+1 in key-to-id resolution by adding/using IIdKeyMap.GetIdsForKeys(Guid[] keys, UmbracoObjectTypes type)

Memory Allocation Issues Identified

1. Excessive ToArray/ToList materializations: Lines 1170, 814, 2650 - materialize collections just to iterate
2. String allocations in hot paths: Lines 1201, 2596-2598 - string concat in loops/move operations
3. Lambda/closure allocations: Line 1125-1127 - creates list and closure on every save
4. Dictionary recreations: Lines 555-556 - creates dictionary then iterates again

Pending Decision: User needs to choose approach:

• Conservative: Fix obvious issues (ToArray before iteration, string concat in loops)
• Moderate: Add StringBuilder pooling, avoid unnecessary materializations
• Aggressive: Full Span/ArrayPool usage, pooled collections

Artifacts

• docs/plans/2025-12-19-contentservice-refactor-design.md - Design document updated to Revision 1.2 with Performance Optimizations section

Action Items & Next Steps

All performance review tasks completed. Design document updated with:

1. ✅ Database Query Efficiency - 4 batch lookup improvements
2. ✅ Memory Allocation Patterns - 7 incremental optimization steps
3. ✅ Concurrency & Locking - 4 lock optimization steps
4. ✅ Caching Strategies - 4 cache optimization steps
5. ✅ Design document updated at docs/plans/2025-12-19-contentservice-refactor-design.md (Revision 1.2)

Next step: Proceed to implementation planning with superpowers:writing-plans

Other Notes

Architecture Context

The refactoring splits ContentService into 5 public services + 2 internal managers:

• IContentCrudService (~400 lines) - Create, Get, Save, Delete
• IContentPublishOperationService (~1000 lines) - Publish, Unpublish, Scheduling
• IContentMoveService (~350 lines) - Move, RecycleBin, Copy, Sort
• IContentQueryService (~250 lines) - Count, Paged queries, Hierarchy
• IContentVersionService (~200 lines) - Versions, Rollback
• ContentPermissionManager (internal) - Permissions
• ContentBlueprintManager (internal) - Blueprints

Key Design Decisions Already Made

1. Naming: IContentPublishOperationService (not IContentPublishingService) to avoid collision with existing API-layer service
2. Scope Pattern: Caller-Creates-Scope (Ambient Scope) - nested scopes participate in parent transaction
3. Lock Coordination: Acquire locks at highest level that creates scope
4. Dependency Direction: Unidirectional - Publish/Move may call CRUD, no reverse dependencies

Relevant Codebase Locations

• Core interfaces: src/Umbraco.Core/Services/
• Repository interfaces: src/Umbraco.Core/Persistence/Repositories/
• Scoping: src/Umbraco.Core/Scoping/
• ID/Key mapping: IIdKeyMap interface for key-to-id resolution