mirror of
https://github.com/crazybber/go-pattern-examples.git
synced 2024-11-26 21:56:02 +03:00
371 lines
11 KiB
Go
371 lines
11 KiB
Go
package gobreaker
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import (
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"fmt"
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"runtime"
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"testing"
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"time"
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"github.com/stretchr/testify/assert"
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)
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var defaultCB *CircuitBreaker
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var customCB *CircuitBreaker
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var negativeDurationCB *CircuitBreaker
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type StateChange struct {
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name string
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from State
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to State
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}
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var stateChange StateChange
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func pseudoSleep(cb *CircuitBreaker, period time.Duration) {
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if !cb.expiry.IsZero() {
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cb.expiry = cb.expiry.Add(-period)
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}
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}
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func succeed(cb *CircuitBreaker) error {
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_, err := cb.Execute(func() (interface{}, error) { return nil, nil })
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return err
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}
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func succeedLater(cb *CircuitBreaker, delay time.Duration) <-chan error {
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ch := make(chan error)
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go func() {
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_, err := cb.Execute(func() (interface{}, error) {
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time.Sleep(delay)
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return nil, nil
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})
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ch <- err
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}()
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return ch
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}
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func succeed2Step(cb *TwoStepCircuitBreaker) error {
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done, err := cb.Allow()
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if err != nil {
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return err
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}
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done(true)
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return nil
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}
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func fail(cb *CircuitBreaker) error {
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msg := "fail"
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_, err := cb.Execute(func() (interface{}, error) { return nil, fmt.Errorf(msg) })
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if err.Error() == msg {
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return nil
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}
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return err
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}
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func fail2Step(cb *TwoStepCircuitBreaker) error {
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done, err := cb.Allow()
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if err != nil {
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return err
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}
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done(false)
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return nil
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}
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func causePanic(cb *CircuitBreaker) error {
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_, err := cb.Execute(func() (interface{}, error) { panic("oops") })
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return err
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}
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func newCustom() *CircuitBreaker {
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var customSt Settings
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customSt.Name = "cb"
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customSt.MaxRequests = 3
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customSt.Interval = time.Duration(30) * time.Second
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customSt.Timeout = time.Duration(90) * time.Second
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customSt.ReadyToTrip = func(counts Counts) bool {
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numReqs := counts.Requests
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failureRatio := float64(counts.TotalFailures) / float64(numReqs)
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counts.clear() // no effect on customCB.counts
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return numReqs >= 3 && failureRatio >= 0.6
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}
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customSt.OnStateChange = func(name string, from State, to State) {
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stateChange = StateChange{name, from, to}
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}
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return NewCircuitBreaker(customSt)
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}
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func newNegativeDurationCB() *CircuitBreaker {
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var negativeSt Settings
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negativeSt.Name = "ncb"
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negativeSt.Interval = time.Duration(-30) * time.Second
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negativeSt.Timeout = time.Duration(-90) * time.Second
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return NewCircuitBreaker(negativeSt)
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}
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func init() {
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defaultCB = NewCircuitBreaker(Settings{})
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customCB = newCustom()
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negativeDurationCB = newNegativeDurationCB()
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}
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func TestStateConstants(t *testing.T) {
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assert.Equal(t, State(0), StateClosed)
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assert.Equal(t, State(1), StateHalfOpen)
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assert.Equal(t, State(2), StateOpen)
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assert.Equal(t, StateClosed.String(), "closed")
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assert.Equal(t, StateHalfOpen.String(), "half-open")
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assert.Equal(t, StateOpen.String(), "open")
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assert.Equal(t, State(100).String(), "unknown state: 100")
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}
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func TestNewCircuitBreaker(t *testing.T) {
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defaultCB := NewCircuitBreaker(Settings{})
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assert.Equal(t, "", defaultCB.name)
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assert.Equal(t, uint32(1), defaultCB.maxRequests)
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assert.Equal(t, time.Duration(0), defaultCB.interval)
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assert.Equal(t, time.Duration(60)*time.Second, defaultCB.timeout)
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assert.NotNil(t, defaultCB.readyToTrip)
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assert.Nil(t, defaultCB.onStateChange)
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assert.Equal(t, StateClosed, defaultCB.state)
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assert.Equal(t, Counts{0, 0, 0, 0, 0}, defaultCB.counts)
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assert.True(t, defaultCB.expiry.IsZero())
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customCB := newCustom()
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assert.Equal(t, "cb", customCB.name)
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assert.Equal(t, uint32(3), customCB.maxRequests)
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assert.Equal(t, time.Duration(30)*time.Second, customCB.interval)
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assert.Equal(t, time.Duration(90)*time.Second, customCB.timeout)
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assert.NotNil(t, customCB.readyToTrip)
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assert.NotNil(t, customCB.onStateChange)
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assert.Equal(t, StateClosed, customCB.state)
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assert.Equal(t, Counts{0, 0, 0, 0, 0}, customCB.counts)
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assert.False(t, customCB.expiry.IsZero())
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negativeDurationCB := newNegativeDurationCB()
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assert.Equal(t, "ncb", negativeDurationCB.name)
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assert.Equal(t, uint32(1), negativeDurationCB.maxRequests)
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assert.Equal(t, time.Duration(0)*time.Second, negativeDurationCB.interval)
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assert.Equal(t, time.Duration(60)*time.Second, negativeDurationCB.timeout)
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assert.NotNil(t, negativeDurationCB.readyToTrip)
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assert.Nil(t, negativeDurationCB.onStateChange)
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assert.Equal(t, StateClosed, negativeDurationCB.state)
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assert.Equal(t, Counts{0, 0, 0, 0, 0}, negativeDurationCB.counts)
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assert.True(t, negativeDurationCB.expiry.IsZero())
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}
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func TestDefaultCircuitBreaker(t *testing.T) {
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assert.Equal(t, "", defaultCB.Name())
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for i := 0; i < 5; i++ {
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assert.Nil(t, fail(defaultCB))
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}
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assert.Equal(t, StateClosed, defaultCB.State())
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assert.Equal(t, Counts{5, 0, 5, 0, 5}, defaultCB.counts)
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assert.Nil(t, succeed(defaultCB))
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assert.Equal(t, StateClosed, defaultCB.State())
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assert.Equal(t, Counts{6, 1, 5, 1, 0}, defaultCB.counts)
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assert.Nil(t, fail(defaultCB))
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assert.Equal(t, StateClosed, defaultCB.State())
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assert.Equal(t, Counts{7, 1, 6, 0, 1}, defaultCB.counts)
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// StateClosed to StateOpen
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for i := 0; i < 5; i++ {
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assert.Nil(t, fail(defaultCB)) // 6 consecutive failures
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}
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assert.Equal(t, StateOpen, defaultCB.State())
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assert.Equal(t, Counts{0, 0, 0, 0, 0}, defaultCB.counts)
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assert.False(t, defaultCB.expiry.IsZero())
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assert.Error(t, succeed(defaultCB))
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assert.Error(t, fail(defaultCB))
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assert.Equal(t, Counts{0, 0, 0, 0, 0}, defaultCB.counts)
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pseudoSleep(defaultCB, time.Duration(59)*time.Second)
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assert.Equal(t, StateOpen, defaultCB.State())
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// StateOpen to StateHalfOpen
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pseudoSleep(defaultCB, time.Duration(1)*time.Second) // over Timeout
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assert.Equal(t, StateHalfOpen, defaultCB.State())
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assert.True(t, defaultCB.expiry.IsZero())
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// StateHalfOpen to StateOpen
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assert.Nil(t, fail(defaultCB))
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assert.Equal(t, StateOpen, defaultCB.State())
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assert.Equal(t, Counts{0, 0, 0, 0, 0}, defaultCB.counts)
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assert.False(t, defaultCB.expiry.IsZero())
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// StateOpen to StateHalfOpen
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pseudoSleep(defaultCB, time.Duration(60)*time.Second)
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assert.Equal(t, StateHalfOpen, defaultCB.State())
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assert.True(t, defaultCB.expiry.IsZero())
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// StateHalfOpen to StateClosed
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assert.Nil(t, succeed(defaultCB))
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assert.Equal(t, StateClosed, defaultCB.State())
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assert.Equal(t, Counts{0, 0, 0, 0, 0}, defaultCB.counts)
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assert.True(t, defaultCB.expiry.IsZero())
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}
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func TestCustomCircuitBreaker(t *testing.T) {
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assert.Equal(t, "cb", customCB.Name())
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for i := 0; i < 5; i++ {
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assert.Nil(t, succeed(customCB))
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assert.Nil(t, fail(customCB))
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}
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assert.Equal(t, StateClosed, customCB.State())
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assert.Equal(t, Counts{10, 5, 5, 0, 1}, customCB.counts)
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pseudoSleep(customCB, time.Duration(29)*time.Second)
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assert.Nil(t, succeed(customCB))
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assert.Equal(t, StateClosed, customCB.State())
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assert.Equal(t, Counts{11, 6, 5, 1, 0}, customCB.counts)
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pseudoSleep(customCB, time.Duration(1)*time.Second) // over Interval
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assert.Nil(t, fail(customCB))
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assert.Equal(t, StateClosed, customCB.State())
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assert.Equal(t, Counts{1, 0, 1, 0, 1}, customCB.counts)
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// StateClosed to StateOpen
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assert.Nil(t, succeed(customCB))
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assert.Nil(t, fail(customCB)) // failure ratio: 2/3 >= 0.6
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assert.Equal(t, StateOpen, customCB.State())
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assert.Equal(t, Counts{0, 0, 0, 0, 0}, customCB.counts)
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assert.False(t, customCB.expiry.IsZero())
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assert.Equal(t, StateChange{"cb", StateClosed, StateOpen}, stateChange)
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// StateOpen to StateHalfOpen
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pseudoSleep(customCB, time.Duration(90)*time.Second)
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assert.Equal(t, StateHalfOpen, customCB.State())
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assert.True(t, defaultCB.expiry.IsZero())
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assert.Equal(t, StateChange{"cb", StateOpen, StateHalfOpen}, stateChange)
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assert.Nil(t, succeed(customCB))
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assert.Nil(t, succeed(customCB))
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assert.Equal(t, StateHalfOpen, customCB.State())
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assert.Equal(t, Counts{2, 2, 0, 2, 0}, customCB.counts)
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// StateHalfOpen to StateClosed
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ch := succeedLater(customCB, time.Duration(100)*time.Millisecond) // 3 consecutive successes
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time.Sleep(time.Duration(50) * time.Millisecond)
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assert.Equal(t, Counts{3, 2, 0, 2, 0}, customCB.counts)
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assert.Error(t, succeed(customCB)) // over MaxRequests
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assert.Nil(t, <-ch)
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assert.Equal(t, StateClosed, customCB.State())
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assert.Equal(t, Counts{0, 0, 0, 0, 0}, customCB.counts)
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assert.False(t, customCB.expiry.IsZero())
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assert.Equal(t, StateChange{"cb", StateHalfOpen, StateClosed}, stateChange)
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}
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func TestTwoStepCircuitBreaker(t *testing.T) {
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tscb := NewTwoStepCircuitBreaker(Settings{Name: "tscb"})
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assert.Equal(t, "tscb", tscb.Name())
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for i := 0; i < 5; i++ {
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assert.Nil(t, fail2Step(tscb))
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}
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assert.Equal(t, StateClosed, tscb.State())
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assert.Equal(t, Counts{5, 0, 5, 0, 5}, tscb.cb.counts)
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assert.Nil(t, succeed2Step(tscb))
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assert.Equal(t, StateClosed, tscb.State())
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assert.Equal(t, Counts{6, 1, 5, 1, 0}, tscb.cb.counts)
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assert.Nil(t, fail2Step(tscb))
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assert.Equal(t, StateClosed, tscb.State())
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assert.Equal(t, Counts{7, 1, 6, 0, 1}, tscb.cb.counts)
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// StateClosed to StateOpen
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for i := 0; i < 5; i++ {
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assert.Nil(t, fail2Step(tscb)) // 6 consecutive failures
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}
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assert.Equal(t, StateOpen, tscb.State())
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assert.Equal(t, Counts{0, 0, 0, 0, 0}, tscb.cb.counts)
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assert.False(t, tscb.cb.expiry.IsZero())
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assert.Error(t, succeed2Step(tscb))
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assert.Error(t, fail2Step(tscb))
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assert.Equal(t, Counts{0, 0, 0, 0, 0}, tscb.cb.counts)
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pseudoSleep(tscb.cb, time.Duration(59)*time.Second)
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assert.Equal(t, StateOpen, tscb.State())
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// StateOpen to StateHalfOpen
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pseudoSleep(tscb.cb, time.Duration(1)*time.Second) // over Timeout
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assert.Equal(t, StateHalfOpen, tscb.State())
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assert.True(t, tscb.cb.expiry.IsZero())
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// StateHalfOpen to StateOpen
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assert.Nil(t, fail2Step(tscb))
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assert.Equal(t, StateOpen, tscb.State())
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assert.Equal(t, Counts{0, 0, 0, 0, 0}, tscb.cb.counts)
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assert.False(t, tscb.cb.expiry.IsZero())
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// StateOpen to StateHalfOpen
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pseudoSleep(tscb.cb, time.Duration(60)*time.Second)
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assert.Equal(t, StateHalfOpen, tscb.State())
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assert.True(t, tscb.cb.expiry.IsZero())
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// StateHalfOpen to StateClosed
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assert.Nil(t, succeed2Step(tscb))
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assert.Equal(t, StateClosed, tscb.State())
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assert.Equal(t, Counts{0, 0, 0, 0, 0}, tscb.cb.counts)
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assert.True(t, tscb.cb.expiry.IsZero())
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}
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func TestPanicInRequest(t *testing.T) {
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assert.Panics(t, func() { causePanic(defaultCB) })
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assert.Equal(t, Counts{1, 0, 1, 0, 1}, defaultCB.counts)
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}
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func TestGeneration(t *testing.T) {
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pseudoSleep(customCB, time.Duration(29)*time.Second)
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assert.Nil(t, succeed(customCB))
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ch := succeedLater(customCB, time.Duration(1500)*time.Millisecond)
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time.Sleep(time.Duration(500) * time.Millisecond)
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assert.Equal(t, Counts{2, 1, 0, 1, 0}, customCB.counts)
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time.Sleep(time.Duration(500) * time.Millisecond) // over Interval
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assert.Equal(t, StateClosed, customCB.State())
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assert.Equal(t, Counts{0, 0, 0, 0, 0}, customCB.counts)
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// the request from the previous generation has no effect on customCB.counts
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assert.Nil(t, <-ch)
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assert.Equal(t, Counts{0, 0, 0, 0, 0}, customCB.counts)
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}
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func TestCircuitBreakerInParallel(t *testing.T) {
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runtime.GOMAXPROCS(runtime.NumCPU())
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ch := make(chan error)
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const numReqs = 10000
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routine := func() {
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for i := 0; i < numReqs; i++ {
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ch <- succeed(customCB)
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}
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}
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const numRoutines = 10
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for i := 0; i < numRoutines; i++ {
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go routine()
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}
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total := uint32(numReqs * numRoutines)
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for i := uint32(0); i < total; i++ {
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err := <-ch
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assert.Nil(t, err)
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}
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assert.Equal(t, Counts{total, total, 0, total, 0}, customCB.counts)
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}
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