initial add - go fmt on grpc
Change-Id: Ib0afadd2fe5571d1456a091f94f5644458f7d3f4
diff --git a/vendor/google.golang.org/grpc/internal/backoff/backoff.go b/vendor/google.golang.org/grpc/internal/backoff/backoff.go
new file mode 100644
index 0000000..1bd0cce
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/backoff/backoff.go
@@ -0,0 +1,78 @@
+/*
+ *
+ * Copyright 2017 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 backoff implement the backoff strategy for gRPC.
+//
+// This is kept in internal until the gRPC project decides whether or not to
+// allow alternative backoff strategies.
+package backoff
+
+import (
+ "time"
+
+ "google.golang.org/grpc/internal/grpcrand"
+)
+
+// Strategy defines the methodology for backing off after a grpc connection
+// failure.
+//
+type Strategy interface {
+ // Backoff returns the amount of time to wait before the next retry given
+ // the number of consecutive failures.
+ Backoff(retries int) time.Duration
+}
+
+const (
+ // baseDelay is the amount of time to wait before retrying after the first
+ // failure.
+ baseDelay = 1.0 * time.Second
+ // factor is applied to the backoff after each retry.
+ factor = 1.6
+ // jitter provides a range to randomize backoff delays.
+ jitter = 0.2
+)
+
+// Exponential implements exponential backoff algorithm as defined in
+// https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md.
+type Exponential struct {
+ // MaxDelay is the upper bound of backoff delay.
+ MaxDelay time.Duration
+}
+
+// Backoff returns the amount of time to wait before the next retry given the
+// number of retries.
+func (bc Exponential) Backoff(retries int) time.Duration {
+ if retries == 0 {
+ return baseDelay
+ }
+ backoff, max := float64(baseDelay), float64(bc.MaxDelay)
+ for backoff < max && retries > 0 {
+ backoff *= factor
+ retries--
+ }
+ if backoff > max {
+ backoff = max
+ }
+ // Randomize backoff delays so that if a cluster of requests start at
+ // the same time, they won't operate in lockstep.
+ backoff *= 1 + jitter*(grpcrand.Float64()*2-1)
+ if backoff < 0 {
+ return 0
+ }
+ return time.Duration(backoff)
+}