VOL-2362 - add exponential backoff around enabling indications
Change-Id: I212312f297a0ca5ae33a4250bac1008e9be2f2c2
diff --git a/vendor/github.com/cenkalti/backoff/v3/.gitignore b/vendor/github.com/cenkalti/backoff/v3/.gitignore
new file mode 100644
index 0000000..0026861
--- /dev/null
+++ b/vendor/github.com/cenkalti/backoff/v3/.gitignore
@@ -0,0 +1,22 @@
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
diff --git a/vendor/github.com/cenkalti/backoff/v3/.travis.yml b/vendor/github.com/cenkalti/backoff/v3/.travis.yml
new file mode 100644
index 0000000..47a6a46
--- /dev/null
+++ b/vendor/github.com/cenkalti/backoff/v3/.travis.yml
@@ -0,0 +1,10 @@
+language: go
+go:
+ - 1.7
+ - 1.x
+ - tip
+before_install:
+ - go get github.com/mattn/goveralls
+ - go get golang.org/x/tools/cmd/cover
+script:
+ - $HOME/gopath/bin/goveralls -service=travis-ci
diff --git a/vendor/github.com/cenkalti/backoff/v3/LICENSE b/vendor/github.com/cenkalti/backoff/v3/LICENSE
new file mode 100644
index 0000000..89b8179
--- /dev/null
+++ b/vendor/github.com/cenkalti/backoff/v3/LICENSE
@@ -0,0 +1,20 @@
+The MIT License (MIT)
+
+Copyright (c) 2014 Cenk Altı
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/vendor/github.com/cenkalti/backoff/v3/README.md b/vendor/github.com/cenkalti/backoff/v3/README.md
new file mode 100644
index 0000000..3673df4
--- /dev/null
+++ b/vendor/github.com/cenkalti/backoff/v3/README.md
@@ -0,0 +1,33 @@
+# Exponential Backoff [![GoDoc][godoc image]][godoc] [![Build Status][travis image]][travis] [![Coverage Status][coveralls image]][coveralls]
+
+This is a Go port of the exponential backoff algorithm from [Google's HTTP Client Library for Java][google-http-java-client].
+
+[Exponential backoff][exponential backoff wiki]
+is an algorithm that uses feedback to multiplicatively decrease the rate of some process,
+in order to gradually find an acceptable rate.
+The retries exponentially increase and stop increasing when a certain threshold is met.
+
+## Usage
+
+Import path is `github.com/cenkalti/backoff/v3`. Please note the version part at the end.
+
+godoc.org does not support modules yet,
+so you can use https://godoc.org/gopkg.in/cenkalti/backoff.v3 to view the documentation.
+
+## Contributing
+
+* I would like to keep this library as small as possible.
+* Please don't send a PR without opening an issue and discussing it first.
+* If proposed change is not a common use case, I will probably not accept it.
+
+[godoc]: https://godoc.org/github.com/cenkalti/backoff
+[godoc image]: https://godoc.org/github.com/cenkalti/backoff?status.png
+[travis]: https://travis-ci.org/cenkalti/backoff
+[travis image]: https://travis-ci.org/cenkalti/backoff.png?branch=master
+[coveralls]: https://coveralls.io/github/cenkalti/backoff?branch=master
+[coveralls image]: https://coveralls.io/repos/github/cenkalti/backoff/badge.svg?branch=master
+
+[google-http-java-client]: https://github.com/google/google-http-java-client/blob/da1aa993e90285ec18579f1553339b00e19b3ab5/google-http-client/src/main/java/com/google/api/client/util/ExponentialBackOff.java
+[exponential backoff wiki]: http://en.wikipedia.org/wiki/Exponential_backoff
+
+[advanced example]: https://godoc.org/github.com/cenkalti/backoff#example_
diff --git a/vendor/github.com/cenkalti/backoff/v3/backoff.go b/vendor/github.com/cenkalti/backoff/v3/backoff.go
new file mode 100644
index 0000000..3676ee4
--- /dev/null
+++ b/vendor/github.com/cenkalti/backoff/v3/backoff.go
@@ -0,0 +1,66 @@
+// Package backoff implements backoff algorithms for retrying operations.
+//
+// Use Retry function for retrying operations that may fail.
+// If Retry does not meet your needs,
+// copy/paste the function into your project and modify as you wish.
+//
+// There is also Ticker type similar to time.Ticker.
+// You can use it if you need to work with channels.
+//
+// See Examples section below for usage examples.
+package backoff
+
+import "time"
+
+// BackOff is a backoff policy for retrying an operation.
+type BackOff interface {
+ // NextBackOff returns the duration to wait before retrying the operation,
+ // or backoff. Stop to indicate that no more retries should be made.
+ //
+ // Example usage:
+ //
+ // duration := backoff.NextBackOff();
+ // if (duration == backoff.Stop) {
+ // // Do not retry operation.
+ // } else {
+ // // Sleep for duration and retry operation.
+ // }
+ //
+ NextBackOff() time.Duration
+
+ // Reset to initial state.
+ Reset()
+}
+
+// Stop indicates that no more retries should be made for use in NextBackOff().
+const Stop time.Duration = -1
+
+// ZeroBackOff is a fixed backoff policy whose backoff time is always zero,
+// meaning that the operation is retried immediately without waiting, indefinitely.
+type ZeroBackOff struct{}
+
+func (b *ZeroBackOff) Reset() {}
+
+func (b *ZeroBackOff) NextBackOff() time.Duration { return 0 }
+
+// StopBackOff is a fixed backoff policy that always returns backoff.Stop for
+// NextBackOff(), meaning that the operation should never be retried.
+type StopBackOff struct{}
+
+func (b *StopBackOff) Reset() {}
+
+func (b *StopBackOff) NextBackOff() time.Duration { return Stop }
+
+// ConstantBackOff is a backoff policy that always returns the same backoff delay.
+// This is in contrast to an exponential backoff policy,
+// which returns a delay that grows longer as you call NextBackOff() over and over again.
+type ConstantBackOff struct {
+ Interval time.Duration
+}
+
+func (b *ConstantBackOff) Reset() {}
+func (b *ConstantBackOff) NextBackOff() time.Duration { return b.Interval }
+
+func NewConstantBackOff(d time.Duration) *ConstantBackOff {
+ return &ConstantBackOff{Interval: d}
+}
diff --git a/vendor/github.com/cenkalti/backoff/v3/context.go b/vendor/github.com/cenkalti/backoff/v3/context.go
new file mode 100644
index 0000000..7f78421
--- /dev/null
+++ b/vendor/github.com/cenkalti/backoff/v3/context.go
@@ -0,0 +1,63 @@
+package backoff
+
+import (
+ "context"
+ "time"
+)
+
+// BackOffContext is a backoff policy that stops retrying after the context
+// is canceled.
+type BackOffContext interface { // nolint: golint
+ BackOff
+ Context() context.Context
+}
+
+type backOffContext struct {
+ BackOff
+ ctx context.Context
+}
+
+// WithContext returns a BackOffContext with context ctx
+//
+// ctx must not be nil
+func WithContext(b BackOff, ctx context.Context) BackOffContext { // nolint: golint
+ if ctx == nil {
+ panic("nil context")
+ }
+
+ if b, ok := b.(*backOffContext); ok {
+ return &backOffContext{
+ BackOff: b.BackOff,
+ ctx: ctx,
+ }
+ }
+
+ return &backOffContext{
+ BackOff: b,
+ ctx: ctx,
+ }
+}
+
+func ensureContext(b BackOff) BackOffContext {
+ if cb, ok := b.(BackOffContext); ok {
+ return cb
+ }
+ return WithContext(b, context.Background())
+}
+
+func (b *backOffContext) Context() context.Context {
+ return b.ctx
+}
+
+func (b *backOffContext) NextBackOff() time.Duration {
+ select {
+ case <-b.ctx.Done():
+ return Stop
+ default:
+ }
+ next := b.BackOff.NextBackOff()
+ if deadline, ok := b.ctx.Deadline(); ok && deadline.Sub(time.Now()) < next { // nolint: gosimple
+ return Stop
+ }
+ return next
+}
diff --git a/vendor/github.com/cenkalti/backoff/v3/exponential.go b/vendor/github.com/cenkalti/backoff/v3/exponential.go
new file mode 100644
index 0000000..cb11cc1
--- /dev/null
+++ b/vendor/github.com/cenkalti/backoff/v3/exponential.go
@@ -0,0 +1,154 @@
+package backoff
+
+import (
+ "math/rand"
+ "time"
+)
+
+/*
+ExponentialBackOff is a backoff implementation that increases the backoff
+period for each retry attempt using a randomization function that grows exponentially.
+
+NextBackOff() is calculated using the following formula:
+
+ randomized interval =
+ RetryInterval * (random value in range [1 - RandomizationFactor, 1 + RandomizationFactor])
+
+In other words NextBackOff() will range between the randomization factor
+percentage below and above the retry interval.
+
+For example, given the following parameters:
+
+ RetryInterval = 2
+ RandomizationFactor = 0.5
+ Multiplier = 2
+
+the actual backoff period used in the next retry attempt will range between 1 and 3 seconds,
+multiplied by the exponential, that is, between 2 and 6 seconds.
+
+Note: MaxInterval caps the RetryInterval and not the randomized interval.
+
+If the time elapsed since an ExponentialBackOff instance is created goes past the
+MaxElapsedTime, then the method NextBackOff() starts returning backoff.Stop.
+
+The elapsed time can be reset by calling Reset().
+
+Example: Given the following default arguments, for 10 tries the sequence will be,
+and assuming we go over the MaxElapsedTime on the 10th try:
+
+ Request # RetryInterval (seconds) Randomized Interval (seconds)
+
+ 1 0.5 [0.25, 0.75]
+ 2 0.75 [0.375, 1.125]
+ 3 1.125 [0.562, 1.687]
+ 4 1.687 [0.8435, 2.53]
+ 5 2.53 [1.265, 3.795]
+ 6 3.795 [1.897, 5.692]
+ 7 5.692 [2.846, 8.538]
+ 8 8.538 [4.269, 12.807]
+ 9 12.807 [6.403, 19.210]
+ 10 19.210 backoff.Stop
+
+Note: Implementation is not thread-safe.
+*/
+type ExponentialBackOff struct {
+ InitialInterval time.Duration
+ RandomizationFactor float64
+ Multiplier float64
+ MaxInterval time.Duration
+ // After MaxElapsedTime the ExponentialBackOff stops.
+ // It never stops if MaxElapsedTime == 0.
+ MaxElapsedTime time.Duration
+ Clock Clock
+
+ currentInterval time.Duration
+ startTime time.Time
+}
+
+// Clock is an interface that returns current time for BackOff.
+type Clock interface {
+ Now() time.Time
+}
+
+// Default values for ExponentialBackOff.
+const (
+ DefaultInitialInterval = 500 * time.Millisecond
+ DefaultRandomizationFactor = 0.5
+ DefaultMultiplier = 1.5
+ DefaultMaxInterval = 60 * time.Second
+ DefaultMaxElapsedTime = 15 * time.Minute
+)
+
+// NewExponentialBackOff creates an instance of ExponentialBackOff using default values.
+func NewExponentialBackOff() *ExponentialBackOff {
+ b := &ExponentialBackOff{
+ InitialInterval: DefaultInitialInterval,
+ RandomizationFactor: DefaultRandomizationFactor,
+ Multiplier: DefaultMultiplier,
+ MaxInterval: DefaultMaxInterval,
+ MaxElapsedTime: DefaultMaxElapsedTime,
+ Clock: SystemClock,
+ }
+ b.Reset()
+ return b
+}
+
+type systemClock struct{}
+
+func (t systemClock) Now() time.Time {
+ return time.Now()
+}
+
+// SystemClock implements Clock interface that uses time.Now().
+var SystemClock = systemClock{}
+
+// Reset the interval back to the initial retry interval and restarts the timer.
+// Reset must be called before using b.
+func (b *ExponentialBackOff) Reset() {
+ b.currentInterval = b.InitialInterval
+ b.startTime = b.Clock.Now()
+}
+
+// NextBackOff calculates the next backoff interval using the formula:
+// Randomized interval = RetryInterval * (1 ± RandomizationFactor)
+func (b *ExponentialBackOff) NextBackOff() time.Duration {
+ // Make sure we have not gone over the maximum elapsed time.
+ if b.MaxElapsedTime != 0 && b.GetElapsedTime() > b.MaxElapsedTime {
+ return Stop
+ }
+ defer b.incrementCurrentInterval()
+ return getRandomValueFromInterval(b.RandomizationFactor, rand.Float64(), b.currentInterval)
+}
+
+// GetElapsedTime returns the elapsed time since an ExponentialBackOff instance
+// is created and is reset when Reset() is called.
+//
+// The elapsed time is computed using time.Now().UnixNano(). It is
+// safe to call even while the backoff policy is used by a running
+// ticker.
+func (b *ExponentialBackOff) GetElapsedTime() time.Duration {
+ return b.Clock.Now().Sub(b.startTime)
+}
+
+// Increments the current interval by multiplying it with the multiplier.
+func (b *ExponentialBackOff) incrementCurrentInterval() {
+ // Check for overflow, if overflow is detected set the current interval to the max interval.
+ if float64(b.currentInterval) >= float64(b.MaxInterval)/b.Multiplier {
+ b.currentInterval = b.MaxInterval
+ } else {
+ b.currentInterval = time.Duration(float64(b.currentInterval) * b.Multiplier)
+ }
+}
+
+// Returns a random value from the following interval:
+// [randomizationFactor * currentInterval, randomizationFactor * currentInterval].
+func getRandomValueFromInterval(randomizationFactor, random float64, currentInterval time.Duration) time.Duration {
+ var delta = randomizationFactor * float64(currentInterval)
+ var minInterval = float64(currentInterval) - delta
+ var maxInterval = float64(currentInterval) + delta
+
+ // Get a random value from the range [minInterval, maxInterval].
+ // The formula used below has a +1 because if the minInterval is 1 and the maxInterval is 3 then
+ // we want a 33% chance for selecting either 1, 2 or 3.
+ return time.Duration(minInterval + (random * (maxInterval - minInterval + 1)))
+}
diff --git a/vendor/github.com/cenkalti/backoff/v3/go.mod b/vendor/github.com/cenkalti/backoff/v3/go.mod
new file mode 100644
index 0000000..479e62a
--- /dev/null
+++ b/vendor/github.com/cenkalti/backoff/v3/go.mod
@@ -0,0 +1,3 @@
+module github.com/cenkalti/backoff/v3
+
+go 1.12
diff --git a/vendor/github.com/cenkalti/backoff/v3/retry.go b/vendor/github.com/cenkalti/backoff/v3/retry.go
new file mode 100644
index 0000000..e4c6c9c
--- /dev/null
+++ b/vendor/github.com/cenkalti/backoff/v3/retry.go
@@ -0,0 +1,86 @@
+package backoff
+
+import "time"
+
+// An Operation is executing by Retry() or RetryNotify().
+// The operation will be retried using a backoff policy if it returns an error.
+type Operation func() error
+
+// Notify is a notify-on-error function. It receives an operation error and
+// backoff delay if the operation failed (with an error).
+//
+// NOTE that if the backoff policy stated to stop retrying,
+// the notify function isn't called.
+type Notify func(error, time.Duration)
+
+// Retry the operation o until it does not return error or BackOff stops.
+// o is guaranteed to be run at least once.
+//
+// If o returns a *PermanentError, the operation is not retried, and the
+// wrapped error is returned.
+//
+// Retry sleeps the goroutine for the duration returned by BackOff after a
+// failed operation returns.
+func Retry(o Operation, b BackOff) error { return RetryNotify(o, b, nil) }
+
+// RetryNotify calls notify function with the error and wait duration
+// for each failed attempt before sleep.
+func RetryNotify(operation Operation, b BackOff, notify Notify) error {
+ var err error
+ var next time.Duration
+ var t *time.Timer
+
+ cb := ensureContext(b)
+
+ b.Reset()
+ for {
+ if err = operation(); err == nil {
+ return nil
+ }
+
+ if permanent, ok := err.(*PermanentError); ok {
+ return permanent.Err
+ }
+
+ if next = cb.NextBackOff(); next == Stop {
+ return err
+ }
+
+ if notify != nil {
+ notify(err, next)
+ }
+
+ if t == nil {
+ t = time.NewTimer(next)
+ defer t.Stop()
+ } else {
+ t.Reset(next)
+ }
+
+ select {
+ case <-cb.Context().Done():
+ return err
+ case <-t.C:
+ }
+ }
+}
+
+// PermanentError signals that the operation should not be retried.
+type PermanentError struct {
+ Err error
+}
+
+func (e *PermanentError) Error() string {
+ return e.Err.Error()
+}
+
+func (e *PermanentError) Unwrap() error {
+ return e.Err
+}
+
+// Permanent wraps the given err in a *PermanentError.
+func Permanent(err error) *PermanentError {
+ return &PermanentError{
+ Err: err,
+ }
+}
diff --git a/vendor/github.com/cenkalti/backoff/v3/ticker.go b/vendor/github.com/cenkalti/backoff/v3/ticker.go
new file mode 100644
index 0000000..e41084b
--- /dev/null
+++ b/vendor/github.com/cenkalti/backoff/v3/ticker.go
@@ -0,0 +1,82 @@
+package backoff
+
+import (
+ "sync"
+ "time"
+)
+
+// Ticker holds a channel that delivers `ticks' of a clock at times reported by a BackOff.
+//
+// Ticks will continue to arrive when the previous operation is still running,
+// so operations that take a while to fail could run in quick succession.
+type Ticker struct {
+ C <-chan time.Time
+ c chan time.Time
+ b BackOffContext
+ stop chan struct{}
+ stopOnce sync.Once
+}
+
+// NewTicker returns a new Ticker containing a channel that will send
+// the time at times specified by the BackOff argument. Ticker is
+// guaranteed to tick at least once. The channel is closed when Stop
+// method is called or BackOff stops. It is not safe to manipulate the
+// provided backoff policy (notably calling NextBackOff or Reset)
+// while the ticker is running.
+func NewTicker(b BackOff) *Ticker {
+ c := make(chan time.Time)
+ t := &Ticker{
+ C: c,
+ c: c,
+ b: ensureContext(b),
+ stop: make(chan struct{}),
+ }
+ t.b.Reset()
+ go t.run()
+ return t
+}
+
+// Stop turns off a ticker. After Stop, no more ticks will be sent.
+func (t *Ticker) Stop() {
+ t.stopOnce.Do(func() { close(t.stop) })
+}
+
+func (t *Ticker) run() {
+ c := t.c
+ defer close(c)
+
+ // Ticker is guaranteed to tick at least once.
+ afterC := t.send(time.Now())
+
+ for {
+ if afterC == nil {
+ return
+ }
+
+ select {
+ case tick := <-afterC:
+ afterC = t.send(tick)
+ case <-t.stop:
+ t.c = nil // Prevent future ticks from being sent to the channel.
+ return
+ case <-t.b.Context().Done():
+ return
+ }
+ }
+}
+
+func (t *Ticker) send(tick time.Time) <-chan time.Time {
+ select {
+ case t.c <- tick:
+ case <-t.stop:
+ return nil
+ }
+
+ next := t.b.NextBackOff()
+ if next == Stop {
+ t.Stop()
+ return nil
+ }
+
+ return time.After(next)
+}
diff --git a/vendor/github.com/cenkalti/backoff/v3/tries.go b/vendor/github.com/cenkalti/backoff/v3/tries.go
new file mode 100644
index 0000000..cfeefd9
--- /dev/null
+++ b/vendor/github.com/cenkalti/backoff/v3/tries.go
@@ -0,0 +1,35 @@
+package backoff
+
+import "time"
+
+/*
+WithMaxRetries creates a wrapper around another BackOff, which will
+return Stop if NextBackOff() has been called too many times since
+the last time Reset() was called
+
+Note: Implementation is not thread-safe.
+*/
+func WithMaxRetries(b BackOff, max uint64) BackOff {
+ return &backOffTries{delegate: b, maxTries: max}
+}
+
+type backOffTries struct {
+ delegate BackOff
+ maxTries uint64
+ numTries uint64
+}
+
+func (b *backOffTries) NextBackOff() time.Duration {
+ if b.maxTries > 0 {
+ if b.maxTries <= b.numTries {
+ return Stop
+ }
+ b.numTries++
+ }
+ return b.delegate.NextBackOff()
+}
+
+func (b *backOffTries) Reset() {
+ b.numTries = 0
+ b.delegate.Reset()
+}