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Mostlylucid.Ephemeral.Atoms.Echo 2.6.3

Mostlylucid.Ephemeral.Atoms.Echo

Type-aware echoes for the important operations that survive just long enough to tell their story.

This atom watches the same operation window that the coordinators expose, listens for typed signals (via TypedSignalSink<TPayload>), and when the coordinator trims an operation it builds a compact OperationEchoEntry<TPayload> that you can persist through an OperationEchoAtom<TPayload> or inspect in-process. It is especially handy for attribute-driven jobs because they already run inside coordinators and can raise typed signals with payloads describing their most critical state.

Sample: capture the final state of attribute jobs

var signalSink = new SignalSink();
var typedSink = new TypedSignalSink<EchoPayload>(signalSink);
var echoAtom = new OperationEchoAtom<EchoPayload>(async echo => await echoStore.AppendAsync(echo));

await using var coordinator = new EphemeralWorkCoordinator<Order>(
 async (order, ct) =>
 {
 // work...
 typedSink.Raise("echo.capture", new EchoPayload
 {
 OrderId = order.Id,
 Status = "persisting key artifacts"
 }, key: order.CustomerId);
 });

using var maker = coordinator.EnableOperationEchoing(
 typedSink,
 echoAtom,
 new OperationEchoMakerOptions<EchoPayload>
 {
 ActivationSignalPattern = "echo.capture",
 CaptureSignalPattern = "echo.*",
 MaxTrackedOperations = 128
 });

The atom keeps the echo window bounded (MaxTrackedOperations) and self-cleans stale captures (MaxCaptureAge). Because the typed sink reuses the shared SignalSink, any other listeners still see the untyped SignalEvent.

Attribute-friendly wiring

Decorated jobs can signal their own critical payloads:

[EphemeralJob("orders.acknowledge")]
public Task OnAckAsync(SignalEvent evt)
{
 var payload = new EchoPayload
 {
 OrderId = evt.Key,
 Message = "ready for hand-off"
 };

 typedSink.Raise("echo.capture", payload, key: evt.Key);
 return Task.CompletedTask;
}

Because TypedSignalSink<TPayload> raises both typed and untyped events, the echo maker captures the payload while the rest of your signal pipeline keeps running unchanged.

Configuration tips

• ActivationSignalPattern lets you mark the point when an operation becomes echo-worthy ("echo.capture" in the sample). When set, the maker only captures signals after that activation signal (default is null to capture eagerly).
• CaptureSignalPattern and CapturePredicate let you filter which signals become part of the echo so you can ignore noise.
• CaptureActivationSignal controls whether the activation signal itself is included in the echo.
• MaxTrackedOperations / MaxCaptureAge keep the working set bounded so the echo maker doesn’t leak memory when collectors or consumers are slow.

Use OperationEchoAtom<TPayload> and EnableOperationEchoing(...) to persist echoes, replay them during diagnostics, or trigger downstream recovery logic.