[VOL-3678] First implementation of the BBSim-sadis-server
Change-Id: I5077a8f861f4cc6af9759f31a4a415042c05eba3
diff --git a/vendor/k8s.io/apimachinery/pkg/util/wait/doc.go b/vendor/k8s.io/apimachinery/pkg/util/wait/doc.go
new file mode 100644
index 0000000..3f0c968
--- /dev/null
+++ b/vendor/k8s.io/apimachinery/pkg/util/wait/doc.go
@@ -0,0 +1,19 @@
+/*
+Copyright 2014 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 wait provides tools for polling or listening for changes
+// to a condition.
+package wait // import "k8s.io/apimachinery/pkg/util/wait"
diff --git a/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go b/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go
new file mode 100644
index 0000000..d759d91
--- /dev/null
+++ b/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go
@@ -0,0 +1,606 @@
+/*
+Copyright 2014 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 wait
+
+import (
+ "context"
+ "errors"
+ "math"
+ "math/rand"
+ "sync"
+ "time"
+
+ "k8s.io/apimachinery/pkg/util/clock"
+ "k8s.io/apimachinery/pkg/util/runtime"
+)
+
+// For any test of the style:
+// ...
+// <- time.After(timeout):
+// t.Errorf("Timed out")
+// The value for timeout should effectively be "forever." Obviously we don't want our tests to truly lock up forever, but 30s
+// is long enough that it is effectively forever for the things that can slow down a run on a heavily contended machine
+// (GC, seeks, etc), but not so long as to make a developer ctrl-c a test run if they do happen to break that test.
+var ForeverTestTimeout = time.Second * 30
+
+// NeverStop may be passed to Until to make it never stop.
+var NeverStop <-chan struct{} = make(chan struct{})
+
+// Group allows to start a group of goroutines and wait for their completion.
+type Group struct {
+ wg sync.WaitGroup
+}
+
+func (g *Group) Wait() {
+ g.wg.Wait()
+}
+
+// StartWithChannel starts f in a new goroutine in the group.
+// stopCh is passed to f as an argument. f should stop when stopCh is available.
+func (g *Group) StartWithChannel(stopCh <-chan struct{}, f func(stopCh <-chan struct{})) {
+ g.Start(func() {
+ f(stopCh)
+ })
+}
+
+// StartWithContext starts f in a new goroutine in the group.
+// ctx is passed to f as an argument. f should stop when ctx.Done() is available.
+func (g *Group) StartWithContext(ctx context.Context, f func(context.Context)) {
+ g.Start(func() {
+ f(ctx)
+ })
+}
+
+// Start starts f in a new goroutine in the group.
+func (g *Group) Start(f func()) {
+ g.wg.Add(1)
+ go func() {
+ defer g.wg.Done()
+ f()
+ }()
+}
+
+// Forever calls f every period for ever.
+//
+// Forever is syntactic sugar on top of Until.
+func Forever(f func(), period time.Duration) {
+ Until(f, period, NeverStop)
+}
+
+// Until loops until stop channel is closed, running f every period.
+//
+// Until is syntactic sugar on top of JitterUntil with zero jitter factor and
+// with sliding = true (which means the timer for period starts after the f
+// completes).
+func Until(f func(), period time.Duration, stopCh <-chan struct{}) {
+ JitterUntil(f, period, 0.0, true, stopCh)
+}
+
+// UntilWithContext loops until context is done, running f every period.
+//
+// UntilWithContext is syntactic sugar on top of JitterUntilWithContext
+// with zero jitter factor and with sliding = true (which means the timer
+// for period starts after the f completes).
+func UntilWithContext(ctx context.Context, f func(context.Context), period time.Duration) {
+ JitterUntilWithContext(ctx, f, period, 0.0, true)
+}
+
+// NonSlidingUntil loops until stop channel is closed, running f every
+// period.
+//
+// NonSlidingUntil is syntactic sugar on top of JitterUntil with zero jitter
+// factor, with sliding = false (meaning the timer for period starts at the same
+// time as the function starts).
+func NonSlidingUntil(f func(), period time.Duration, stopCh <-chan struct{}) {
+ JitterUntil(f, period, 0.0, false, stopCh)
+}
+
+// NonSlidingUntilWithContext loops until context is done, running f every
+// period.
+//
+// NonSlidingUntilWithContext is syntactic sugar on top of JitterUntilWithContext
+// with zero jitter factor, with sliding = false (meaning the timer for period
+// starts at the same time as the function starts).
+func NonSlidingUntilWithContext(ctx context.Context, f func(context.Context), period time.Duration) {
+ JitterUntilWithContext(ctx, f, period, 0.0, false)
+}
+
+// JitterUntil loops until stop channel is closed, running f every period.
+//
+// If jitterFactor is positive, the period is jittered before every run of f.
+// If jitterFactor is not positive, the period is unchanged and not jittered.
+//
+// If sliding is true, the period is computed after f runs. If it is false then
+// period includes the runtime for f.
+//
+// Close stopCh to stop. f may not be invoked if stop channel is already
+// closed. Pass NeverStop to if you don't want it stop.
+func JitterUntil(f func(), period time.Duration, jitterFactor float64, sliding bool, stopCh <-chan struct{}) {
+ BackoffUntil(f, NewJitteredBackoffManager(period, jitterFactor, &clock.RealClock{}), sliding, stopCh)
+}
+
+// BackoffUntil loops until stop channel is closed, run f every duration given by BackoffManager.
+//
+// If sliding is true, the period is computed after f runs. If it is false then
+// period includes the runtime for f.
+func BackoffUntil(f func(), backoff BackoffManager, sliding bool, stopCh <-chan struct{}) {
+ var t clock.Timer
+ for {
+ select {
+ case <-stopCh:
+ return
+ default:
+ }
+
+ if !sliding {
+ t = backoff.Backoff()
+ }
+
+ func() {
+ defer runtime.HandleCrash()
+ f()
+ }()
+
+ if sliding {
+ t = backoff.Backoff()
+ }
+
+ // NOTE: b/c there is no priority selection in golang
+ // it is possible for this to race, meaning we could
+ // trigger t.C and stopCh, and t.C select falls through.
+ // In order to mitigate we re-check stopCh at the beginning
+ // of every loop to prevent extra executions of f().
+ select {
+ case <-stopCh:
+ return
+ case <-t.C():
+ }
+ }
+}
+
+// JitterUntilWithContext loops until context is done, running f every period.
+//
+// If jitterFactor is positive, the period is jittered before every run of f.
+// If jitterFactor is not positive, the period is unchanged and not jittered.
+//
+// If sliding is true, the period is computed after f runs. If it is false then
+// period includes the runtime for f.
+//
+// Cancel context to stop. f may not be invoked if context is already expired.
+func JitterUntilWithContext(ctx context.Context, f func(context.Context), period time.Duration, jitterFactor float64, sliding bool) {
+ JitterUntil(func() { f(ctx) }, period, jitterFactor, sliding, ctx.Done())
+}
+
+// Jitter returns a time.Duration between duration and duration + maxFactor *
+// duration.
+//
+// This allows clients to avoid converging on periodic behavior. If maxFactor
+// is 0.0, a suggested default value will be chosen.
+func Jitter(duration time.Duration, maxFactor float64) time.Duration {
+ if maxFactor <= 0.0 {
+ maxFactor = 1.0
+ }
+ wait := duration + time.Duration(rand.Float64()*maxFactor*float64(duration))
+ return wait
+}
+
+// ErrWaitTimeout is returned when the condition exited without success.
+var ErrWaitTimeout = errors.New("timed out waiting for the condition")
+
+// ConditionFunc returns true if the condition is satisfied, or an error
+// if the loop should be aborted.
+type ConditionFunc func() (done bool, err error)
+
+// runConditionWithCrashProtection runs a ConditionFunc with crash protection
+func runConditionWithCrashProtection(condition ConditionFunc) (bool, error) {
+ defer runtime.HandleCrash()
+ return condition()
+}
+
+// Backoff holds parameters applied to a Backoff function.
+type Backoff struct {
+ // The initial duration.
+ Duration time.Duration
+ // Duration is multiplied by factor each iteration, if factor is not zero
+ // and the limits imposed by Steps and Cap have not been reached.
+ // Should not be negative.
+ // The jitter does not contribute to the updates to the duration parameter.
+ Factor float64
+ // The sleep at each iteration is the duration plus an additional
+ // amount chosen uniformly at random from the interval between
+ // zero and `jitter*duration`.
+ Jitter float64
+ // The remaining number of iterations in which the duration
+ // parameter may change (but progress can be stopped earlier by
+ // hitting the cap). If not positive, the duration is not
+ // changed. Used for exponential backoff in combination with
+ // Factor and Cap.
+ Steps int
+ // A limit on revised values of the duration parameter. If a
+ // multiplication by the factor parameter would make the duration
+ // exceed the cap then the duration is set to the cap and the
+ // steps parameter is set to zero.
+ Cap time.Duration
+}
+
+// Step (1) returns an amount of time to sleep determined by the
+// original Duration and Jitter and (2) mutates the provided Backoff
+// to update its Steps and Duration.
+func (b *Backoff) Step() time.Duration {
+ if b.Steps < 1 {
+ if b.Jitter > 0 {
+ return Jitter(b.Duration, b.Jitter)
+ }
+ return b.Duration
+ }
+ b.Steps--
+
+ duration := b.Duration
+
+ // calculate the next step
+ if b.Factor != 0 {
+ b.Duration = time.Duration(float64(b.Duration) * b.Factor)
+ if b.Cap > 0 && b.Duration > b.Cap {
+ b.Duration = b.Cap
+ b.Steps = 0
+ }
+ }
+
+ if b.Jitter > 0 {
+ duration = Jitter(duration, b.Jitter)
+ }
+ return duration
+}
+
+// contextForChannel derives a child context from a parent channel.
+//
+// The derived context's Done channel is closed when the returned cancel function
+// is called or when the parent channel is closed, whichever happens first.
+//
+// Note the caller must *always* call the CancelFunc, otherwise resources may be leaked.
+func contextForChannel(parentCh <-chan struct{}) (context.Context, context.CancelFunc) {
+ ctx, cancel := context.WithCancel(context.Background())
+
+ go func() {
+ select {
+ case <-parentCh:
+ cancel()
+ case <-ctx.Done():
+ }
+ }()
+ return ctx, cancel
+}
+
+// BackoffManager manages backoff with a particular scheme based on its underlying implementation. It provides
+// an interface to return a timer for backoff, and caller shall backoff until Timer.C() drains. If the second Backoff()
+// is called before the timer from the first Backoff() call finishes, the first timer will NOT be drained and result in
+// undetermined behavior.
+// The BackoffManager is supposed to be called in a single-threaded environment.
+type BackoffManager interface {
+ Backoff() clock.Timer
+}
+
+type exponentialBackoffManagerImpl struct {
+ backoff *Backoff
+ backoffTimer clock.Timer
+ lastBackoffStart time.Time
+ initialBackoff time.Duration
+ backoffResetDuration time.Duration
+ clock clock.Clock
+}
+
+// NewExponentialBackoffManager returns a manager for managing exponential backoff. Each backoff is jittered and
+// backoff will not exceed the given max. If the backoff is not called within resetDuration, the backoff is reset.
+// This backoff manager is used to reduce load during upstream unhealthiness.
+func NewExponentialBackoffManager(initBackoff, maxBackoff, resetDuration time.Duration, backoffFactor, jitter float64, c clock.Clock) BackoffManager {
+ return &exponentialBackoffManagerImpl{
+ backoff: &Backoff{
+ Duration: initBackoff,
+ Factor: backoffFactor,
+ Jitter: jitter,
+
+ // the current impl of wait.Backoff returns Backoff.Duration once steps are used up, which is not
+ // what we ideally need here, we set it to max int and assume we will never use up the steps
+ Steps: math.MaxInt32,
+ Cap: maxBackoff,
+ },
+ backoffTimer: nil,
+ initialBackoff: initBackoff,
+ lastBackoffStart: c.Now(),
+ backoffResetDuration: resetDuration,
+ clock: c,
+ }
+}
+
+func (b *exponentialBackoffManagerImpl) getNextBackoff() time.Duration {
+ if b.clock.Now().Sub(b.lastBackoffStart) > b.backoffResetDuration {
+ b.backoff.Steps = math.MaxInt32
+ b.backoff.Duration = b.initialBackoff
+ }
+ b.lastBackoffStart = b.clock.Now()
+ return b.backoff.Step()
+}
+
+// Backoff implements BackoffManager.Backoff, it returns a timer so caller can block on the timer for exponential backoff.
+// The returned timer must be drained before calling Backoff() the second time
+func (b *exponentialBackoffManagerImpl) Backoff() clock.Timer {
+ if b.backoffTimer == nil {
+ b.backoffTimer = b.clock.NewTimer(b.getNextBackoff())
+ } else {
+ b.backoffTimer.Reset(b.getNextBackoff())
+ }
+ return b.backoffTimer
+}
+
+type jitteredBackoffManagerImpl struct {
+ clock clock.Clock
+ duration time.Duration
+ jitter float64
+ backoffTimer clock.Timer
+}
+
+// NewJitteredBackoffManager returns a BackoffManager that backoffs with given duration plus given jitter. If the jitter
+// is negative, backoff will not be jittered.
+func NewJitteredBackoffManager(duration time.Duration, jitter float64, c clock.Clock) BackoffManager {
+ return &jitteredBackoffManagerImpl{
+ clock: c,
+ duration: duration,
+ jitter: jitter,
+ backoffTimer: nil,
+ }
+}
+
+func (j *jitteredBackoffManagerImpl) getNextBackoff() time.Duration {
+ jitteredPeriod := j.duration
+ if j.jitter > 0.0 {
+ jitteredPeriod = Jitter(j.duration, j.jitter)
+ }
+ return jitteredPeriod
+}
+
+// Backoff implements BackoffManager.Backoff, it returns a timer so caller can block on the timer for jittered backoff.
+// The returned timer must be drained before calling Backoff() the second time
+func (j *jitteredBackoffManagerImpl) Backoff() clock.Timer {
+ backoff := j.getNextBackoff()
+ if j.backoffTimer == nil {
+ j.backoffTimer = j.clock.NewTimer(backoff)
+ } else {
+ j.backoffTimer.Reset(backoff)
+ }
+ return j.backoffTimer
+}
+
+// ExponentialBackoff repeats a condition check with exponential backoff.
+//
+// It repeatedly checks the condition and then sleeps, using `backoff.Step()`
+// to determine the length of the sleep and adjust Duration and Steps.
+// Stops and returns as soon as:
+// 1. the condition check returns true or an error,
+// 2. `backoff.Steps` checks of the condition have been done, or
+// 3. a sleep truncated by the cap on duration has been completed.
+// In case (1) the returned error is what the condition function returned.
+// In all other cases, ErrWaitTimeout is returned.
+func ExponentialBackoff(backoff Backoff, condition ConditionFunc) error {
+ for backoff.Steps > 0 {
+ if ok, err := runConditionWithCrashProtection(condition); err != nil || ok {
+ return err
+ }
+ if backoff.Steps == 1 {
+ break
+ }
+ time.Sleep(backoff.Step())
+ }
+ return ErrWaitTimeout
+}
+
+// Poll tries a condition func until it returns true, an error, or the timeout
+// is reached.
+//
+// Poll always waits the interval before the run of 'condition'.
+// 'condition' will always be invoked at least once.
+//
+// Some intervals may be missed if the condition takes too long or the time
+// window is too short.
+//
+// If you want to Poll something forever, see PollInfinite.
+func Poll(interval, timeout time.Duration, condition ConditionFunc) error {
+ return pollInternal(poller(interval, timeout), condition)
+}
+
+func pollInternal(wait WaitFunc, condition ConditionFunc) error {
+ done := make(chan struct{})
+ defer close(done)
+ return WaitFor(wait, condition, done)
+}
+
+// PollImmediate tries a condition func until it returns true, an error, or the timeout
+// is reached.
+//
+// PollImmediate always checks 'condition' before waiting for the interval. 'condition'
+// will always be invoked at least once.
+//
+// Some intervals may be missed if the condition takes too long or the time
+// window is too short.
+//
+// If you want to immediately Poll something forever, see PollImmediateInfinite.
+func PollImmediate(interval, timeout time.Duration, condition ConditionFunc) error {
+ return pollImmediateInternal(poller(interval, timeout), condition)
+}
+
+func pollImmediateInternal(wait WaitFunc, condition ConditionFunc) error {
+ done, err := runConditionWithCrashProtection(condition)
+ if err != nil {
+ return err
+ }
+ if done {
+ return nil
+ }
+ return pollInternal(wait, condition)
+}
+
+// PollInfinite tries a condition func until it returns true or an error
+//
+// PollInfinite always waits the interval before the run of 'condition'.
+//
+// Some intervals may be missed if the condition takes too long or the time
+// window is too short.
+func PollInfinite(interval time.Duration, condition ConditionFunc) error {
+ done := make(chan struct{})
+ defer close(done)
+ return PollUntil(interval, condition, done)
+}
+
+// PollImmediateInfinite tries a condition func until it returns true or an error
+//
+// PollImmediateInfinite runs the 'condition' before waiting for the interval.
+//
+// Some intervals may be missed if the condition takes too long or the time
+// window is too short.
+func PollImmediateInfinite(interval time.Duration, condition ConditionFunc) error {
+ done, err := runConditionWithCrashProtection(condition)
+ if err != nil {
+ return err
+ }
+ if done {
+ return nil
+ }
+ return PollInfinite(interval, condition)
+}
+
+// PollUntil tries a condition func until it returns true, an error or stopCh is
+// closed.
+//
+// PollUntil always waits interval before the first run of 'condition'.
+// 'condition' will always be invoked at least once.
+func PollUntil(interval time.Duration, condition ConditionFunc, stopCh <-chan struct{}) error {
+ ctx, cancel := contextForChannel(stopCh)
+ defer cancel()
+ return WaitFor(poller(interval, 0), condition, ctx.Done())
+}
+
+// PollImmediateUntil tries a condition func until it returns true, an error or stopCh is closed.
+//
+// PollImmediateUntil runs the 'condition' before waiting for the interval.
+// 'condition' will always be invoked at least once.
+func PollImmediateUntil(interval time.Duration, condition ConditionFunc, stopCh <-chan struct{}) error {
+ done, err := condition()
+ if err != nil {
+ return err
+ }
+ if done {
+ return nil
+ }
+ select {
+ case <-stopCh:
+ return ErrWaitTimeout
+ default:
+ return PollUntil(interval, condition, stopCh)
+ }
+}
+
+// WaitFunc creates a channel that receives an item every time a test
+// should be executed and is closed when the last test should be invoked.
+type WaitFunc func(done <-chan struct{}) <-chan struct{}
+
+// WaitFor continually checks 'fn' as driven by 'wait'.
+//
+// WaitFor gets a channel from 'wait()'', and then invokes 'fn' once for every value
+// placed on the channel and once more when the channel is closed. If the channel is closed
+// and 'fn' returns false without error, WaitFor returns ErrWaitTimeout.
+//
+// If 'fn' returns an error the loop ends and that error is returned. If
+// 'fn' returns true the loop ends and nil is returned.
+//
+// ErrWaitTimeout will be returned if the 'done' channel is closed without fn ever
+// returning true.
+//
+// When the done channel is closed, because the golang `select` statement is
+// "uniform pseudo-random", the `fn` might still run one or multiple time,
+// though eventually `WaitFor` will return.
+func WaitFor(wait WaitFunc, fn ConditionFunc, done <-chan struct{}) error {
+ stopCh := make(chan struct{})
+ defer close(stopCh)
+ c := wait(stopCh)
+ for {
+ select {
+ case _, open := <-c:
+ ok, err := runConditionWithCrashProtection(fn)
+ if err != nil {
+ return err
+ }
+ if ok {
+ return nil
+ }
+ if !open {
+ return ErrWaitTimeout
+ }
+ case <-done:
+ return ErrWaitTimeout
+ }
+ }
+}
+
+// poller returns a WaitFunc that will send to the channel every interval until
+// timeout has elapsed and then closes the channel.
+//
+// Over very short intervals you may receive no ticks before the channel is
+// closed. A timeout of 0 is interpreted as an infinity, and in such a case
+// it would be the caller's responsibility to close the done channel.
+// Failure to do so would result in a leaked goroutine.
+//
+// Output ticks are not buffered. If the channel is not ready to receive an
+// item, the tick is skipped.
+func poller(interval, timeout time.Duration) WaitFunc {
+ return WaitFunc(func(done <-chan struct{}) <-chan struct{} {
+ ch := make(chan struct{})
+
+ go func() {
+ defer close(ch)
+
+ tick := time.NewTicker(interval)
+ defer tick.Stop()
+
+ var after <-chan time.Time
+ if timeout != 0 {
+ // time.After is more convenient, but it
+ // potentially leaves timers around much longer
+ // than necessary if we exit early.
+ timer := time.NewTimer(timeout)
+ after = timer.C
+ defer timer.Stop()
+ }
+
+ for {
+ select {
+ case <-tick.C:
+ // If the consumer isn't ready for this signal drop it and
+ // check the other channels.
+ select {
+ case ch <- struct{}{}:
+ default:
+ }
+ case <-after:
+ return
+ case <-done:
+ return
+ }
+ }
+ }()
+
+ return ch
+ })
+}