1 files changed, 107 insertions, 0 deletions
diff --git a/vendor/k8s.io/client-go/rest/urlbackoff.go b/vendor/k8s.io/client-go/rest/urlbackoff.go
new file mode 100644
index 000000000..eff848abc
--- /dev/null
+++ b/vendor/k8s.io/client-go/rest/urlbackoff.go
@@ -0,0 +1,107 @@
+/*
+Copyright 2015 The Kubernetes 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 rest
+
+import (
+	"net/url"
+	"time"
+
+	"github.com/golang/glog"
+	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/client-go/util/flowcontrol"
+)
+
+// Set of resp. Codes that we backoff for.
+// In general these should be errors that indicate a server is overloaded.
+// These shouldn't be configured by any user, we set them based on conventions
+// described in
+var serverIsOverloadedSet = sets.NewInt(429)
+var maxResponseCode = 499
+
+type BackoffManager interface {
+	UpdateBackoff(actualUrl *url.URL, err error, responseCode int)
+	CalculateBackoff(actualUrl *url.URL) time.Duration
+	Sleep(d time.Duration)
+}
+
+// URLBackoff struct implements the semantics on top of Backoff which
+// we need for URL specific exponential backoff.
+type URLBackoff struct {
+	// Uses backoff as underlying implementation.
+	Backoff *flowcontrol.Backoff
+}
+
+// NoBackoff is a stub implementation, can be used for mocking or else as a default.
+type NoBackoff struct {
+}
+
+func (n *NoBackoff) UpdateBackoff(actualUrl *url.URL, err error, responseCode int) {
+	// do nothing.
+}
+
+func (n *NoBackoff) CalculateBackoff(actualUrl *url.URL) time.Duration {
+	return 0 * time.Second
+}
+
+func (n *NoBackoff) Sleep(d time.Duration) {
+	time.Sleep(d)
+}
+
+// Disable makes the backoff trivial, i.e., sets it to zero.  This might be used
+// by tests which want to run 1000s of mock requests without slowing down.
+func (b *URLBackoff) Disable() {
+	glog.V(4).Infof("Disabling backoff strategy")
+	b.Backoff = flowcontrol.NewBackOff(0*time.Second, 0*time.Second)
+}
+
+// baseUrlKey returns the key which urls will be mapped to.
+// For example, 127.0.0.1:8080/api/v2/abcde -> 127.0.0.1:8080.
+func (b *URLBackoff) baseUrlKey(rawurl *url.URL) string {
+	// Simple implementation for now, just the host.
+	// We may backoff specific paths (i.e. "pods") differentially
+	// in the future.
+	host, err := url.Parse(rawurl.String())
+	if err != nil {
+		glog.V(4).Infof("Error extracting url: %v", rawurl)
+		panic("bad url!")
+	}
+	return host.Host
+}
+
+// UpdateBackoff updates backoff metadata
+func (b *URLBackoff) UpdateBackoff(actualUrl *url.URL, err error, responseCode int) {
+	// range for retry counts that we store is [0,13]
+	if responseCode > maxResponseCode || serverIsOverloadedSet.Has(responseCode) {
+		b.Backoff.Next(b.baseUrlKey(actualUrl), b.Backoff.Clock.Now())
+		return
+	} else if responseCode >= 300 || err != nil {
+		glog.V(4).Infof("Client is returning errors: code %v, error %v", responseCode, err)
+	}
+
+	//If we got this far, there is no backoff required for this URL anymore.
+	b.Backoff.Reset(b.baseUrlKey(actualUrl))
+}
+
+// CalculateBackoff takes a url and back's off exponentially,
+// based on its knowledge of existing failures.
+func (b *URLBackoff) CalculateBackoff(actualUrl *url.URL) time.Duration {
+	return b.Backoff.Get(b.baseUrlKey(actualUrl))
+}
+
+func (b *URLBackoff) Sleep(d time.Duration) {
+	b.Backoff.Clock.Sleep(d)
+}