refactor/serializing (#1)

Co-authored-by: matst80 <mats.tornberg@gmail.com>
Reviewed-on: https://git.tornberg.me/mats/go-cart-actor/pulls/1

grain-pool.go

@@ -7,25 +7,27 @@ import (
 )
 
 type GrainPool interface {
-	GetOrSpawn(id string) (Grain, error)
-	Get(id string) (Grain, error)
+	Process(id CartId, messages ...Message) (interface{}, error)
+	Get(id CartId) (Grain, error)
 }
 
 type Ttl struct {
 	Expires time.Time
-	Item    Grain
+	Item    *CartGrain
 }
 
 type GrainLocalPool struct {
-	grains   map[string]Grain
+	grains   map[CartId]*CartGrain
 	expiry   []Ttl
+	spawn    func(id CartId) (*CartGrain, error)
 	Ttl      time.Duration
 	PoolSize int
 }
 
-func NewGrainLocalPool(size int, ttl time.Duration) *GrainLocalPool {
+func NewGrainLocalPool(size int, ttl time.Duration, spawn func(id CartId) (*CartGrain, error)) *GrainLocalPool {
 	ret := &GrainLocalPool{
-		grains:   make(map[string]Grain),
+		spawn:    spawn,
+		grains:   make(map[CartId]*CartGrain),
 		expiry:   make([]Ttl, 0),
 		Ttl:      ttl,
 		PoolSize: size,
@@ -59,11 +61,12 @@ func (p *GrainLocalPool) Purge() {
 	}
 }
 
-func (p *GrainLocalPool) GetGrains() map[string]Grain {
+func (p *GrainLocalPool) GetGrains() map[CartId]*CartGrain {
 	return p.grains
 }
 
-func (p *GrainLocalPool) GetOrSpawn(id string, generator func(id string) Grain) (Grain, error) {
+func (p *GrainLocalPool) GetGrain(id CartId) (*CartGrain, error) {
+	var err error
 	grain, ok := p.grains[id]
 	if !ok {
 		if len(p.grains) >= p.PoolSize {
@@ -74,16 +77,23 @@ func (p *GrainLocalPool) GetOrSpawn(id string, generator func(id string) Grain)
 				return nil, fmt.Errorf("pool is full")
 			}
 		}
-		grain = generator(id)
+		grain, err = p.spawn(id)
+
 		p.grains[id] = grain
 	}
-	return grain, nil
+	return grain, err
 }
 
-func (p *GrainLocalPool) Get(id string) (Grain, error) {
-	grain, ok := p.grains[id]
-	if !ok {
-		return nil, fmt.Errorf("grain not found")
+func (p *GrainLocalPool) Process(id CartId, messages ...Message) (interface{}, error) {
+	grain, err := p.GetGrain(id)
+	if err == nil && grain != nil {
+		for _, message := range messages {
+			_, err = grain.HandleMessage(&message, false)
+		}
 	}
-	return grain, nil
+	return grain, err
+}
+
+func (p *GrainLocalPool) Get(id CartId) (Grain, error) {
+	return p.GetGrain(id)
 }