fix(eventstore): prevent allocation of filtered events (#6749)

* fix(eventstore): prevent allocation of filtered events

Directly reduce each event obtained from a sql.Rows scan,
so that we do not have to allocate all events in a slice.

* reinstate the mutex as RWMutex

* scan data directly

* add todos

* fix(writemodels): add reduce of parent

* test: remove comment

* update comments

---------

Co-authored-by: adlerhurst <silvan.reusser@gmail.com>

internal/command/existing_label_policies_model.go

@@ -38,7 +38,7 @@ func (rm *ExistingLabelPoliciesReadModel) Reduce() error {
 			}
 		}
 	}
-	return nil
+	return rm.WriteModel.Reduce()
 }
 
 func (rm *ExistingLabelPoliciesReadModel) Query() *eventstore.SearchQueryBuilder {

internal/command/instance_domain_model.go

@@ -55,7 +55,7 @@ func (wm *InstanceDomainWriteModel) Reduce() error {
 			wm.State = domain.InstanceDomainStateRemoved
 		}
 	}
-	return nil
+	return wm.WriteModel.Reduce()
 }
 
 func (wm *InstanceDomainWriteModel) Query() *eventstore.SearchQueryBuilder {

internal/command/instance_model.go

@@ -60,7 +60,7 @@ func (wm *InstanceWriteModel) Reduce() error {
 			wm.DefaultLanguage = e.Language
 		}
 	}
-	return nil
+	return wm.WriteModel.Reduce()
 }
 
 func (wm *InstanceWriteModel) Query() *eventstore.SearchQueryBuilder {

internal/command/org_domain_model.go

@@ -84,7 +84,7 @@ func (wm *OrgDomainWriteModel) Reduce() error {
 			wm.ValidationCode = nil
 		}
 	}
-	return nil
+	return wm.WriteModel.Reduce()
 }
 
 func (wm *OrgDomainWriteModel) Query() *eventstore.SearchQueryBuilder {
@@ -154,7 +154,7 @@ func (wm *OrgDomainsWriteModel) Reduce() error {
 			}
 		}
 	}
-	return nil
+	return wm.WriteModel.Reduce()
 }
 
 func (wm *OrgDomainsWriteModel) Query() *eventstore.SearchQueryBuilder {
@@ -216,7 +216,7 @@ func (wm *OrgDomainVerifiedWriteModel) Reduce() error {
 			wm.Verified = false
 		}
 	}
-	return nil
+	return wm.WriteModel.Reduce()
 }
 
 func (wm *OrgDomainVerifiedWriteModel) Query() *eventstore.SearchQueryBuilder {

internal/command/preparation/command.go

@@ -25,6 +25,8 @@ var (
 )
 
 // PrepareCommands checks the passed validations and if ok creates the commands
+//
+// Deprecated: filter causes unneeded allocation. Use [eventstore.FilterToQueryReducer] instead.
 func PrepareCommands(ctx context.Context, filter FilterToQueryReducer, validations ...Validation) (cmds []eventstore.Command, err error) {
 	commanders, err := validate(validations)
 	if err != nil {

internal/command/quota_model.go

@@ -79,7 +79,7 @@ func (wm *quotaWriteModel) Reduce() error {
 	}
 	// wm.WriteModel.Reduce() sets the aggregateID to the first event's aggregateID, but we need the last one
 	wm.AggregateID = wm.rollingAggregateID
-	return nil
+	return wm.WriteModel.Reduce()
 }
 
 // NewChanges returns all changes that need to be applied to the aggregate.

internal/command/system_model.go

@@ -94,7 +94,7 @@ func (wm *SystemConfigWriteModel) Reduce() error {
 			}
 		}
 	}
-	return nil
+	return wm.WriteModel.Reduce()
 }
 
 func (wm *SystemConfigWriteModel) Query() *eventstore.SearchQueryBuilder {

internal/command/unique_constraints_model.go

@@ -183,7 +183,7 @@ func (rm *UniqueConstraintReadModel) Reduce() error {
 			rm.removeUniqueConstraint(e.Aggregate().ID, e.UserID, member.UniqueMember)
 		}
 	}
-	return nil
+	return rm.WriteModel.Reduce()
 }
 
 func (rm *UniqueConstraintReadModel) Query() *eventstore.SearchQueryBuilder {