#96 implement partial read access events emitting

[hu-ahmed]

Resolves: #96

[Copilot]

Pull request overview

This PR implements partial read access event emission functionality, allowing subjects with restricted READ permissions to receive filtered change notifications. The implementation introduces an indexed format for tracking accessible paths per subject, reducing header size when multiple subjects share the same paths.

Key Changes

• Added new header PARTIAL_ACCESS_PATHS to track which JSON paths each subject with partial permissions can access
• Refactored PreDefinedExtraFieldsEnricher into ThingEventEnricher to handle both predefined fields and partial access path enrichment
• Implemented filtering logic in Gateway (SSE, WebSocket) and Connectivity services to restrict event payloads based on subscriber permissions

Reviewed changes

Copilot reviewed 40 out of 40 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
DittoHeaderDefinition.java	Added PARTIAL_ACCESS_PATHS header definition for tracking partial access paths
ThingEventEnricher.java	New enricher that combines predefined fields and partial access path functionality
PartialAccessPathCalculator.java	Core logic for calculating accessible paths for subjects with partial permissions
ReadGrantCollector.java, ReadGrantIndexer.java, ReadGrant.java, IndexedReadGrant.java	Utility classes for collecting and indexing read grants
Enforcer.java	Added getAccessiblePaths method to query accessible paths for authorization contexts
TrieBasedPolicyEnforcer.java, TreeBasedPolicyEnforcer.java, PolicyTrie.java	Implemented getAccessiblePaths in policy enforcers
JsonPartialAccessFilter.java, PartialAccessPathResolver.java, AdaptablePartialAccessFilter.java	Filtering utilities for JSON objects and Adaptables based on partial access paths
ThingsSseRouteBuilder.java, WebSocketRoute.java	Integrated partial access filtering in Gateway streaming endpoints
OutboundMappingProcessor.java	Integrated partial access filtering in Connectivity service for external connections
ThingCommandEnforcement.java	Updated to include partial subjects in read granted subjects
Test files	Added comprehensive test coverage for partial access path functionality

Comments suppressed due to low confidence (1)

things/service/src/test/java/org/eclipse/ditto/things/service/persistence/actors/enrichment/ThingEventEnricherTest.java:1

• Debug statement using System.err should be removed. This appears to be leftover debug code that should not be committed.

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[Copilot]

Pull request overview

Copilot reviewed 47 out of 47 changed files in this pull request and generated no new comments.

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