refactor project structure

cluster/com.go

@@ -0,0 +1,62 @@
+// communicate with peers within cluster
+package cluster
+
+import (
+	"context"
+	"errors"
+	"github.com/hdt3213/godis/interface/redis"
+	"github.com/hdt3213/godis/redis/client"
+	"github.com/hdt3213/godis/redis/reply"
+)
+
+func (cluster *Cluster) getPeerClient(peer string) (*client.Client, error) {
+	connectionFactory, ok := cluster.peerConnection[peer]
+	if !ok {
+		return nil, errors.New("connection factory not found")
+	}
+	raw, err := connectionFactory.BorrowObject(context.Background())
+	if err != nil {
+		return nil, err
+	}
+	conn, ok := raw.(*client.Client)
+	if !ok {
+		return nil, errors.New("connection factory make wrong type")
+	}
+	return conn, nil
+}
+
+func (cluster *Cluster) returnPeerClient(peer string, peerClient *client.Client) error {
+	connectionFactory, ok := cluster.peerConnection[peer]
+	if !ok {
+		return errors.New("connection factory not found")
+	}
+	return connectionFactory.ReturnObject(context.Background(), peerClient)
+}
+
+// relay command to peer
+// cannot call Prepare, Commit, Rollback of self node
+func (cluster *Cluster) Relay(peer string, c redis.Connection, args [][]byte) redis.Reply {
+	if peer == cluster.self {
+		// to self db
+		return cluster.db.Exec(c, args)
+	} else {
+		peerClient, err := cluster.getPeerClient(peer)
+		if err != nil {
+			return reply.MakeErrReply(err.Error())
+		}
+		defer func() {
+			_ = cluster.returnPeerClient(peer, peerClient)
+		}()
+		return peerClient.Send(args)
+	}
+}
+
+// broadcast command to all node in cluster
+func (cluster *Cluster) Broadcast(peer string, c redis.Connection, args [][]byte) map[string]redis.Reply {
+	result := make(map[string]redis.Reply)
+	for _, node := range cluster.peers {
+		reply := cluster.Relay(node, c, args)
+		result[node] = reply
+	}
+	return result
+}