stuff

rpc-pool.go

@@ -0,0 +1,130 @@
+package main
+
+import (
+	"encoding/binary"
+	"net"
+)
+
+const (
+	RemoteGetState      = uint16(0x01)
+	RemoteHandleMessage = uint16(0x02)
+)
+
+type RemoteGrainPool struct {
+	Hosts  []string
+	grains map[CartId]RemoteGrain
+}
+
+func (id CartId) String() string {
+	return string(id[:])
+}
+
+func ToCartId(id string) CartId {
+	var result [16]byte
+	copy(result[:], []byte(id))
+	return result
+}
+
+type RemoteGrain struct {
+	client  net.Conn
+	Id      CartId
+	Address string
+}
+
+func NewRemoteGrain(id CartId, address string) *RemoteGrain {
+	return &RemoteGrain{
+		Id:      id,
+		Address: address,
+	}
+}
+
+func (g *RemoteGrain) Connect() error {
+	if g.client == nil {
+		client, err := net.Dial("tcp", g.Address)
+		if err != nil {
+			return err
+		}
+		g.client = client
+	}
+	return nil
+}
+
+type Packet struct {
+	Version     uint16
+	MessageType uint16
+	Id          CartId
+	DataLength  uint16
+}
+
+func (g *RemoteGrain) SendPacket(messageType uint16, data []byte) error {
+	binary.Write(g.client, binary.LittleEndian, Packet{
+		Version:     2,
+		MessageType: messageType,
+		Id:          g.Id,
+		DataLength:  uint16(len(data)),
+	})
+	return binary.Write(g.client, binary.LittleEndian, data)
+}
+
+func (g *RemoteGrain) HandleMessage(message *Message, isReplay bool) ([]byte, error) {
+	data, err := GetData(message.Write)
+	if err != nil {
+		return nil, err
+	}
+	err = g.SendPacket(RemoteHandleMessage, data)
+	result := make([]byte, 65535)
+	g.client.Read(result)
+	return result, err
+}
+
+func (g *RemoteGrain) GetId() CartId {
+	return g.Id
+}
+
+func (g *RemoteGrain) GetCurrentState() (Grain, error) {
+
+	var reply CartGrain
+	err := g.SendPacket(RemoteGetState, nil)
+	if err != nil {
+		return nil, err
+	}
+	return &reply, err
+}
+
+func NewRemoteGrainPool(addr ...string) *RemoteGrainPool {
+	return &RemoteGrainPool{
+		Hosts:  addr,
+		grains: make(map[CartId]RemoteGrain),
+	}
+}
+
+func (p *RemoteGrainPool) findRemoteGrain(id CartId) *RemoteGrain {
+	grain, ok := p.grains[id]
+	if !ok {
+		return nil
+	}
+	return &grain
+}
+
+func (p *RemoteGrainPool) Process(id CartId, messages ...Message) (interface{}, error) {
+	var result interface{}
+	var err error
+	grain := p.findRemoteGrain(id)
+	if grain == nil {
+		grain = NewRemoteGrain(id, p.Hosts[0])
+		grain.Connect()
+		p.grains[id] = *grain
+	}
+	for _, message := range messages {
+		result, err = grain.HandleMessage(&message, false)
+	}
+	return result, err
+}
+
+func (p *RemoteGrainPool) Get(id CartId) (Grain, error) {
+	grain := p.findRemoteGrain(id)
+	if grain == nil {
+		return nil, nil
+	}
+	return grain.GetCurrentState()
+}