initial import

core/rpc/directclient.go

@@ -0,0 +1,32 @@
+package rpc
+
+import (
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/balancer/roundrobin"
+	"google.golang.org/grpc/connectivity"
+)
+
+type DirectClient struct {
+	conn *grpc.ClientConn
+}
+
+func NewDirectClient(server string, opts ...ClientOption) (*DirectClient, error) {
+	opts = append(opts, WithDialOption(grpc.WithBalancerName(roundrobin.Name)))
+	conn, err := dial(server, opts...)
+	if err != nil {
+		return nil, err
+	}
+
+	return &DirectClient{
+		conn: conn,
+	}, nil
+}
+
+func (c *DirectClient) Next() (*grpc.ClientConn, bool) {
+	state := c.conn.GetState()
+	if state == connectivity.Ready {
+		return c.conn, true
+	} else {
+		return nil, false
+	}
+}