events

func RegisterCompactor ¶

func RegisterCompactor(topic string, compactor interface{})

RegisterCompactor sets the compacter for the given topic.

func WithPoster ¶

func WithPoster(ctx context.Context, poster Poster) context.Context

func WithTopic ¶

func WithTopic(ctx context.Context, topic string) context.Context

WithTopic returns a context with a new topic set, such that events emitted from the resulting context will be marked with the topic.

A topic groups events by the target module they operate on. This is primarily designed to support multi-module log compaction of events. In typical journaling systems, the entries operate on a single data structure. When compacting the journal, we can replace all former log entries with a summary data structure that will result in the same state.

By providing a compaction mechanism by topic, we can prune down to a data structure oriented towards a single topic, leaving unrelated messages alone.

func WithTx ¶

func WithTx(pctx context.Context) (ctx context.Context, commit func(), rollback func(err error))

WithTx returns a new context with an event transaction, such that events posted to the underlying context will be committed to the event log as a group, organized by a transaction id, when commit is called.