add picker.go
diff --git a/picker.go b/picker.go
index 79f9886..d285504 100644
--- a/picker.go
+++ b/picker.go
@@ -35,6 +35,9 @@
import (
"time"
+
+ "golang.org/x/net/context"
+ "google.golang.org/grpc/transport"
)
// Picker picks a Conn for RPC requests.
@@ -42,9 +45,9 @@
type Picker interface {
// Init does initial processing for the Picker, e.g., initiate some connections.
Init(cc *ClientConn) error
- // Pick returns the Conn to use for the upcoming RPC. It may return different
- // Conn's up to the implementation.
- Pick() (*Conn, error)
+ // Pick blocks until either a transport.ClientTransport is ready for the upcoming RPC
+ // or some error happens.
+ Pick(ctx context.Context) (transport.ClientTransport, error)
// State returns the connectivity state of the underlying connections.
State() ConnectivityState
// WaitForStateChange blocks until the state changes to something other than
@@ -70,8 +73,8 @@
return nil
}
-func (p *unicastPicker) Pick() (*Conn, error) {
- return p.conn, nil
+func (p *unicastPicker) Pick(ctx context.Context) (transport.ClientTransport, error) {
+ return p.conn.Wait(ctx)
}
func (p *unicastPicker) State() ConnectivityState {
