Event wrapper adding meta data for the events in the result stream of akka.persistence.query.scaladsl.EventsByTagQuery query, or similar queries.
A query plugin must implement a class that implements this trait.
A query plugin must implement a class that implements this trait. It provides the concrete implementations for the Java and Scala APIs.
A read journal plugin must provide implementations for both
akka.persistence.query.scaladsl.ReadJournal
and akka.persistence.query.javadsl.ReadJournal
.
The plugin must implement both the scaladsl
and the javadsl
traits because the
akka.stream.scaladsl.Source
and akka.stream.javadsl.Source
are different types
and even though those types can easily be converted to each other it is most convenient
for the end user to get access to the Java or Scala Source
directly.
One of the implementations can delegate to the other.
Corresponds to an ordered sequence number for the events.
Corresponds to an ordered sequence number for the events. Note that the corresponding offset of each event is provided in the akka.persistence.query.EventEnvelope, which makes it possible to resume the stream at a later point from a given offset.
The offset
is exclusive, i.e. the event with the exact same sequence number will not be included
in the returned stream. This means that you can use the offset that is returned in EventEnvelope
as the offset
parameter in a subsequent query.
Corresponds to an ordered unique identifier of the events.
Corresponds to an ordered unique identifier of the events. Note that the corresponding offset of each event is provided in the akka.persistence.query.EventEnvelope, which makes it possible to resume the stream at a later point from a given offset.
The offset
is exclusive, i.e. the event with the exact same sequence number will not be included
in the returned stream. This means that you can use the offset that is returned in EventEnvelope
as the offset
parameter in a subsequent query.
Used when retrieving all events.
Persistence extension for queries.