feat(message): add Stoppable interface for graceful subscriber shutdown#678
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SinuheTellez wants to merge 1 commit intoThreeDotsLabs:masterfrom
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feat(message): add Stoppable interface for graceful subscriber shutdown#678SinuheTellez wants to merge 1 commit intoThreeDotsLabs:masterfrom
SinuheTellez wants to merge 1 commit intoThreeDotsLabs:masterfrom
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Relates to ThreeDotsLabs#446 During graceful shutdown, the router now checks if a subscriber implements the Stoppable interface. If so, it calls Stop() first to halt new message delivery, waits for in-flight handlers to finish, then calls Close(). This prevents double-handling caused by in-flight messages losing their chance to be acked or nacked when the subscriber is closed immediately.
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Background/Description
During graceful shutdown the router calls
subscriber.Close()immediately, which cancels in-flight message processing — messages that were mid-handler lose their chance to be acked or nacked. When the subscriber re-connects, those messages get redelivered and double-handled.This adds a
Stoppableinterface (Stop() error) that subscribers can optionally implement.Stop()tells the subscriber to stop delivering new messages while keeping the connection alive so in-flight messages can still be acked or nacked.The router's
handleClosenow checks if the subscriber implementsStoppable. If it does: callStop(), wait for running handlers to finish (runningHandlersWg.Wait()), then callClose(). Non-stoppable subscribers behave exactly as before.The
originalSubscriberfield was added to the handler struct becausedecorateHandlerSubscriberwraps the subscriber withMessageTransformSubscriberDecorator, which doesn't implementStoppable. The type assertion checks the unwrapped subscriber.Relates to #446
Type of Change