feat(eventstore): increase parallel write capabilities (#5940)

This implementation increases parallel write capabilities of the eventstore.
Please have a look at the technical advisories: [05](https://zitadel.com/docs/support/advisory/a10005) and  [06](https://zitadel.com/docs/support/advisory/a10006).
The implementation of eventstore.push is rewritten and stored events are migrated to a new table `eventstore.events2`.
If you are using cockroach: make sure that the database user of ZITADEL has `VIEWACTIVITY` grant. This is used to query events.

internal/eventstore/repository/event.go

@@ -2,24 +2,23 @@ package repository
 
 import (
 	"database/sql"
+	"encoding/json"
 	"time"
+
+	"github.com/zitadel/zitadel/internal/eventstore"
 )
 
-//Event represents all information about a manipulation of an aggregate
+var _ eventstore.Event = (*Event)(nil)
+
+// Event represents all information about a manipulation of an aggregate
 type Event struct {
 	//ID is a generated uuid for this event
 	ID string
 
-	//Sequence is the sequence of the event
-	Sequence uint64
-
-	//PreviousAggregateSequence is the sequence of the previous sequence of the aggregate (e.g. org.250989)
-	// if it's 0 then it's the first event of this aggregate
-	PreviousAggregateSequence uint64
-
-	//PreviousAggregateTypeSequence is the sequence of the previous sequence of the aggregate root (e.g. org)
-	// the first event of the aggregate has previous aggregate root sequence 0
-	PreviousAggregateTypeSequence uint64
+	// Seq is the sequence of the event
+	Seq uint64
+	// Pos is the global sequence of the event multiple events can have the same sequence
+	Pos float64
 
 	//CreationDate is the time the event is created
 	// it's used for human readability.
@@ -27,17 +26,14 @@ type Event struct {
 	// time drifts in different services could cause integrity problems
 	CreationDate time.Time
 
-	//Type describes the cause of the event (e.g. user.added)
+	// Typ describes the cause of the event (e.g. user.added)
 	// it should always be in past-form
-	Type EventType
+	Typ eventstore.EventType
 
 	//Data describe the changed fields (e.g. userName = "hodor")
 	// data must always a pointer to a struct, a struct or a byte array containing json bytes
 	Data []byte
 
-	//EditorService should be a unique identifier for the service which created the event
-	// it's meant for maintainability
-	EditorService string
 	//EditorUser should be a unique identifier for the user which created the event
 	// it's meant for maintainability.
 	// It's recommend to use the aggregate id of the user
@@ -45,13 +41,13 @@ type Event struct {
 
 	//Version describes the definition of the aggregate at a certain point in time
 	// it's used in read models to reduce the events in the correct definition
-	Version Version
+	Version eventstore.Version
 	//AggregateID id is the unique identifier of the aggregate
 	// the client must generate it by it's own
 	AggregateID string
 	//AggregateType describes the meaning of the aggregate for this event
 	// it could an object like user
-	AggregateType AggregateType
+	AggregateType eventstore.AggregateType
 	//ResourceOwner is the organisation which owns this aggregate
 	// an aggregate can only be managed by one organisation
 	// use the ID of the org
@@ -59,10 +55,68 @@ type Event struct {
 	//InstanceID is the instance where this event belongs to
 	// use the ID of the instance
 	InstanceID string
+
+	Constraints []*eventstore.UniqueConstraint
 }
 
-//EventType is the description of the change
-type EventType string
+// Aggregate implements [eventstore.Event]
+func (e *Event) Aggregate() *eventstore.Aggregate {
+	return &eventstore.Aggregate{
+		ID:            e.AggregateID,
+		Type:          e.AggregateType,
+		ResourceOwner: e.ResourceOwner.String,
+		InstanceID:    e.InstanceID,
+		Version:       e.Version,
+	}
+}
 
-//AggregateType is the object name
-type AggregateType string
+// Creator implements [eventstore.Event]
+func (e *Event) Creator() string {
+	return e.EditorUser
+}
+
+// Type implements [eventstore.Event]
+func (e *Event) Type() eventstore.EventType {
+	return e.Typ
+}
+
+// Revision implements [eventstore.Event]
+func (e *Event) Revision() uint16 {
+	return 0
+}
+
+// Sequence implements [eventstore.Event]
+func (e *Event) Sequence() uint64 {
+	return e.Seq
+}
+
+// Position implements [eventstore.Event]
+func (e *Event) Position() float64 {
+	return e.Pos
+}
+
+// CreatedAt implements [eventstore.Event]
+func (e *Event) CreatedAt() time.Time {
+	return e.CreationDate
+}
+
+// Unmarshal implements [eventstore.Event]
+func (e *Event) Unmarshal(ptr any) error {
+	if len(e.Data) == 0 {
+		return nil
+	}
+	return json.Unmarshal(e.Data, ptr)
+}
+
+// DataAsBytes implements [eventstore.Event]
+func (e *Event) DataAsBytes() []byte {
+	return e.Data
+}
+
+func (e *Event) Payload() any {
+	return e.Data
+}
+
+func (e *Event) UniqueConstraints() []*eventstore.UniqueConstraint {
+	return e.Constraints
+}