policies implemented

internal/eventstore/v2/aggregate.go

@@ -0,0 +1,34 @@
+package eventstore
+
+func NewAggregate(id string) *Aggregate {
+	return &Aggregate{
+		ID:     id,
+		Events: []EventPusher{},
+	}
+}
+
+type Aggregate struct {
+	PreviousSequence uint64        `json:"-"`
+	ID               string        `json:"-"`
+	Events           []EventPusher `json:"-"`
+}
+
+//AppendEvents adds all the events to the aggregate.
+// The function doesn't compute the new state of the aggregate
+func (a *Aggregate) AppendEvents(events ...EventPusher) *Aggregate {
+	a.Events = append(a.Events, events...)
+	return a
+}
+
+//Reduce must be the last step in the reduce function of the extension
+func (a *Aggregate) Reduce() error {
+	if len(a.Events) == 0 {
+		return nil
+	}
+
+	a.PreviousSequence = a.Events[len(a.Events)-1].Sequence()
+	// all events processed and not needed anymore
+	a.Events = nil
+	a.Events = []Event{}
+	return nil
+}