From 4d65c62f775d4ece47cdb5af4b7bb6ba843165c8 Mon Sep 17 00:00:00 2001
From: Eric Lippmann <eric.lippmann@icinga.com>
Date: Mon, 4 Oct 2021 13:59:20 +0200
Subject: [PATCH] Handle contracts.Initer in common.NewSyncSubject()

contracts.EntitiyFactoryFunc.WithInit() checked for
contracts.Initer every time.
Now it is only done once in common.NewSyncSubject().
---
 cmd/icingadb/main.go            |  4 ++--
 pkg/common/sync_subject.go      | 17 +++++++++++++++--
 pkg/contracts/contracts.go      | 11 -----------
 pkg/icingadb/runtime_updates.go |  2 +-
 4 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/cmd/icingadb/main.go b/cmd/icingadb/main.go
index 0be0088c..f06b3d21 100644
--- a/cmd/icingadb/main.go
+++ b/cmd/icingadb/main.go
@@ -181,7 +181,7 @@ func run() int {
 							g.Go(func() error {
 								defer configInitSync.Done()
 
-								return s.SyncAfterDump(synctx, common.NewSyncSubject(factory.WithInit), dump)
+								return s.SyncAfterDump(synctx, common.NewSyncSubject(factory), dump)
 							})
 						}
 
@@ -192,7 +192,7 @@ func run() int {
 							g.Go(func() error {
 								defer stateInitSync.Done()
 
-								return s.SyncAfterDump(synctx, common.NewSyncSubject(factory.WithInit), dump)
+								return s.SyncAfterDump(synctx, common.NewSyncSubject(factory), dump)
 							})
 						}
 
diff --git a/pkg/common/sync_subject.go b/pkg/common/sync_subject.go
index 11c1586a..f166b63b 100644
--- a/pkg/common/sync_subject.go
+++ b/pkg/common/sync_subject.go
@@ -15,11 +15,24 @@ type SyncSubject struct {
 // NewSyncSubject returns a new SyncSubject.
 func NewSyncSubject(factoryFunc contracts.EntityFactoryFunc) *SyncSubject {
 	e := factoryFunc()
+
+	var factory contracts.EntityFactoryFunc
+	if _, ok := e.(contracts.Initer); ok {
+		factory = func() contracts.Entity {
+			e := factoryFunc()
+			e.(contracts.Initer).Init()
+
+			return e
+		}
+	} else {
+		factory = factoryFunc
+	}
+
 	_, withChecksum := e.(contracts.Checksumer)
 
 	return &SyncSubject{
 		entity:       e,
-		factory:      factoryFunc,
+		factory:      factory,
 		withChecksum: withChecksum,
 	}
 }
@@ -29,7 +42,7 @@ func (s SyncSubject) Entity() contracts.Entity {
 	return s.entity
 }
 
-// Factory returns the entity factory function.
+// Factory returns the entity factory function that calls Init() on the created contracts.Entity if applicable.
 func (s SyncSubject) Factory() contracts.EntityFactoryFunc {
 	return s.factory
 }
diff --git a/pkg/contracts/contracts.go b/pkg/contracts/contracts.go
index 51594144..0589c249 100644
--- a/pkg/contracts/contracts.go
+++ b/pkg/contracts/contracts.go
@@ -49,17 +49,6 @@ type Checksumer interface {
 // EntityFactoryFunc knows how to create an Entity.
 type EntityFactoryFunc func() Entity
 
-// WithInit calls Init() on the created Entity if applicable.
-func (f EntityFactoryFunc) WithInit() Entity {
-	e := f()
-
-	if initer, ok := e.(Initer); ok {
-		initer.Init()
-	}
-
-	return e
-}
-
 // Waiter implements the Wait method,
 // which blocks until execution is complete.
 type Waiter interface {
diff --git a/pkg/icingadb/runtime_updates.go b/pkg/icingadb/runtime_updates.go
index 4d0ec1a0..5e08dc6e 100644
--- a/pkg/icingadb/runtime_updates.go
+++ b/pkg/icingadb/runtime_updates.go
@@ -61,7 +61,7 @@ func (r *RuntimeUpdates) Sync(ctx context.Context, factoryFuncs []contracts.Enti
 	updateMessagesByKey := make(map[string]chan<- redis.XMessage)
 
 	for _, factoryFunc := range factoryFuncs {
-		s := common.NewSyncSubject(factoryFunc.WithInit)
+		s := common.NewSyncSubject(factoryFunc)
 
 		updateMessages := make(chan redis.XMessage, bulkSize)
 		upsertEntities := make(chan contracts.Entity, bulkSize)