Update libkv dependency

vendor/google.golang.org/grpc/go16.go

@@ -0,0 +1,98 @@
+// +build go1.6,!go1.7
+
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpc
+
+import (
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"os"
+
+	"golang.org/x/net/context"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+	"google.golang.org/grpc/transport"
+)
+
+// dialContext connects to the address on the named network.
+func dialContext(ctx context.Context, network, address string) (net.Conn, error) {
+	return (&net.Dialer{Cancel: ctx.Done()}).Dial(network, address)
+}
+
+func sendHTTPRequest(ctx context.Context, req *http.Request, conn net.Conn) error {
+	req.Cancel = ctx.Done()
+	if err := req.Write(conn); err != nil {
+		return fmt.Errorf("failed to write the HTTP request: %v", err)
+	}
+	return nil
+}
+
+// toRPCErr converts an error into an error from the status package.
+func toRPCErr(err error) error {
+	if _, ok := status.FromError(err); ok {
+		return err
+	}
+	switch e := err.(type) {
+	case transport.StreamError:
+		return status.Error(e.Code, e.Desc)
+	case transport.ConnectionError:
+		return status.Error(codes.Unavailable, e.Desc)
+	default:
+		switch err {
+		case context.DeadlineExceeded:
+			return status.Error(codes.DeadlineExceeded, err.Error())
+		case context.Canceled:
+			return status.Error(codes.Canceled, err.Error())
+		case ErrClientConnClosing:
+			return status.Error(codes.FailedPrecondition, err.Error())
+		}
+	}
+	return status.Error(codes.Unknown, err.Error())
+}
+
+// convertCode converts a standard Go error into its canonical code. Note that
+// this is only used to translate the error returned by the server applications.
+func convertCode(err error) codes.Code {
+	switch err {
+	case nil:
+		return codes.OK
+	case io.EOF:
+		return codes.OutOfRange
+	case io.ErrClosedPipe, io.ErrNoProgress, io.ErrShortBuffer, io.ErrShortWrite, io.ErrUnexpectedEOF:
+		return codes.FailedPrecondition
+	case os.ErrInvalid:
+		return codes.InvalidArgument
+	case context.Canceled:
+		return codes.Canceled
+	case context.DeadlineExceeded:
+		return codes.DeadlineExceeded
+	}
+	switch {
+	case os.IsExist(err):
+		return codes.AlreadyExists
+	case os.IsNotExist(err):
+		return codes.NotFound
+	case os.IsPermission(err):
+		return codes.PermissionDenied
+	}
+	return codes.Unknown
+}