Class EventIndexMatcher<TEvent>

Namespace

DotBoxD.Plugins.Indexing

Assembly

DotBoxD.Plugins.dll

A host's compiled view of a subscription's IndexedPredicate metadata — the "compile the metadata into whatever dispatch/index structure is natural for the runtime" half of issue #47, promoted to the framework by issue #50. It keeps only the predicates whose Path is an EventIndexKeyAttribute property of TEvent (the fields the host indexes) and evaluates them cheaply against an event through precompiled property getters — no per-event reflection, so the index never costs more than it saves.

Because every kept predicate is a necessary AND condition of the real predicate, CouldMatch(TEvent) returning false is always a safe reject; returning true means the event passed the cheap index and the host should still run the verified IR unless the manifest reported full coverage. Conversely, the matcher never rejects on a comparison it cannot soundly decide (a value whose type cannot be reconciled to the property, a null reference, or an ordering it cannot evaluate): such a leaf is dropped or passed through so the verified IR stays the authority. This keeps the invariant "index-reject ⇒ verified-IR-reject" intact even for hand-built or imported manifests whose ValueType disagrees with the property's CLR type.

public sealed class EventIndexMatcher<TEvent>

Type Parameters

TEvent

Inheritance

object

EventIndexMatcher<TEvent>

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Properties

HasIndex

true when at least one manifest predicate mapped onto an indexed field.

public bool HasIndex { get; }

Property Value

bool

HonoredPredicates

The manifest predicates this host can actually serve from an index (path is an index key).

public IReadOnlyList<IndexedPredicate> HonoredPredicates { get; }

Property Value

IReadOnlyList<IndexedPredicate>

IndexKeyNames

The EventIndexKeyAttribute property names of TEvent.

public static IReadOnlyCollection<string> IndexKeyNames { get; }

Property Value

IReadOnlyCollection<string>

Methods

CouldMatch(TEvent)

Evaluates the cheap index checks against value. Returns false as soon as any indexed constraint is definitively violated, so the host can skip dispatch entirely; a constraint it cannot decide is treated as satisfied so the verified IR remains the authority.

public bool CouldMatch(TEvent value)

Parameters

value TEvent

Returns

bool

Create(IReadOnlyList<IndexedPredicate>)

Compiles predicates into cheap index checks, keeping only those whose path is an EventIndexKeyAttribute property of TEvent and whose value can be reconciled to that property's CLR type. A predicate whose value type cannot be reconciled is dropped (left to the verified IR) rather than turned into an unsound or throwing check.

public static EventIndexMatcher<TEvent> Create(IReadOnlyList<IndexedPredicate> predicates)

Parameters

predicates IReadOnlyList<IndexedPredicate>

Returns

EventIndexMatcher<TEvent>