DefinitionRegistry

Remarks

Doc 28's step 6 — "realms reload their definition registry live; no restart, no drain". A catalog is immutable, so a reload is a reference assignment and a reader either sees all of the old one or all of the new one. There is no lock on the read path.

⚠ Not every content change can be applied live, and the two that cannot are checked here. This is where doc 28's walk turned out to be optimistic:

A new tag renumbers the table, and every GameplayTag already sitting in a component, an effect or a packet in flight is an index into the old numbering. Adding an item that uses existing tags is live; adding an item that introduces a tag is a rolling update ([27](../../../docs/plan/27-mmo-framework.md) § Upgrades' build kind). A removed address is never additive. Doc 28 says so and this is where it is enforced: a stack in a bank naming a definition the catalog no longer has is unresolvable, and there is no reading of that which is not data loss. Deprecate, drain, then delete.

Everything else — a new address, a changed value, a retuned loot table — applies.

Fields and properties (3)

• public DefinitionCatalog Catalog

  The definitions in force right now.

• public GameplayTagTable Tags

  The tag table those definitions are numbered against.

• public int Generation

  How many times a reload has been applied. What a diagnostic reports and a test asserts.

Methods (5)

• public DefinitionRegistry(DefinitionCatalog? catalog = null)

  Makes a registry over a catalog.

• public bool TryGet<TDefinition>(DefId id, out TDefinition? definition) where TDefinition : Definition

  Finds a definition and checks it is the kind the caller expected.

• public TDefinition Get<TDefinition>(DefId id) where TDefinition : Definition

  Finds a definition, and refuses to carry on without it.

• public void Reload(DefinitionCatalog next)

  Swaps in a new catalog, if the change is one that can be applied live.

• public bool TryReload(DefinitionCatalog next, out string reason)

  Swaps in a new catalog, and says why not when it will not.

Used by (2)

• DefinitionContentTestsVixen.Gameplay.Content.Tests
• DefinitionRegistryTestsVixen.Gameplay.Tests