major refactor

remote-grain.go

@@ -3,7 +3,6 @@ package main
 import (
 	"fmt"
 	"strings"
-	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
@@ -13,6 +12,25 @@ func (id CartId) String() string {
 	return strings.Trim(string(id[:]), "\x00")
 }
 
+type CartIdPayload struct {
+	Id   CartId
+	Data []byte
+}
+
+func MakeCartInnerFrame(id CartId, payload []byte) []byte {
+	return append(id[:], payload...)
+}
+
+func GetCartFrame(data []byte) (*CartIdPayload, error) {
+	if len(data) < 16 {
+		return nil, fmt.Errorf("data too short")
+	}
+	return &CartIdPayload{
+		Id:   CartId(data[:16]),
+		Data: data[16:],
+	}, nil
+}
+
 func ToCartId(id string) CartId {
 	var result [16]byte
 	copy(result[:], []byte(id))
@@ -20,21 +38,16 @@ func ToCartId(id string) CartId {
 }
 
 type RemoteGrain struct {
-	*CartClient
+	*Connection
 	Id   CartId
 	Host string
 }
 
 func NewRemoteGrain(id CartId, host string) (*RemoteGrain, error) {
-	client, err := CartDial(fmt.Sprintf("%s:1337", host))
-	if err != nil {
-		return nil, err
-	}
-
 	return &RemoteGrain{
 		Id:         id,
 		Host:       host,
-		CartClient: client,
+		Connection: NewConnection(fmt.Sprintf("%s:1337", host)),
 	}, nil
 }
 
@@ -49,47 +62,35 @@ var (
 	})
 )
 
-var start time.Time
+// var start time.Time
 
-func MeasureLatency(fn func() (*CallResult, error)) (*CallResult, error) {
-	start = time.Now()
-	data, err := fn()
-	if err != nil {
-		return data, err
-	}
-	elapsed := time.Since(start).Milliseconds()
-	go func() {
-		remoteCartLatency.Add(float64(elapsed))
-		remoteCartCallsTotal.Inc()
-	}()
-	return data, nil
-}
+// func MeasureLatency(fn func() (*CallResult, error)) (*CallResult, error) {
+// 	start = time.Now()
+// 	data, err := fn()
+// 	if err != nil {
+// 		return data, err
+// 	}
+// 	elapsed := time.Since(start).Milliseconds()
+// 	go func() {
+// 		remoteCartLatency.Add(float64(elapsed))
+// 		remoteCartCallsTotal.Inc()
+// 	}()
+// 	return data, nil
+// }
 
-func (g *RemoteGrain) HandleMessage(message *Message, isReplay bool) (*CallResult, error) {
+func (g *RemoteGrain) HandleMessage(message *Message, isReplay bool) (*FrameWithPayload, error) {
 
 	data, err := GetData(message.Write)
 	if err != nil {
 		return nil, err
 	}
-	reply, err := MeasureLatency(func() (*CallResult, error) {
-		return g.Call(RemoteHandleMutation, g.Id, RemoteHandleMutationReply, data)
-	})
-
-	if err != nil {
-		return nil, err
-	}
-
-	return reply, err
-}
-
-func (g *RemoteGrain) Close() {
-	g.CartClient.PersistentConnection.Close()
+	return g.Call(RemoteHandleMutation, MakeCartInnerFrame(g.Id, data))
 }
 
 func (g *RemoteGrain) GetId() CartId {
 	return g.Id
 }
 
-func (g *RemoteGrain) GetCurrentState() (*CallResult, error) {
-	return MeasureLatency(func() (*CallResult, error) { return g.Call(RemoteGetState, g.Id, RemoteGetStateReply, []byte{}) })
+func (g *RemoteGrain) GetCurrentState() (*FrameWithPayload, error) {
+	return g.Call(RemoteGetState, MakeCartInnerFrame(g.Id, nil))
 }