64 lines
1,005 B
Go
64 lines
1,005 B
Go
package tree
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import (
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"errors"
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"sync"
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"time"
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)
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type (
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circuitBreaker struct {
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breakDuration time.Duration
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threshold int
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mu sync.Mutex
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state map[uint64]state
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}
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state struct {
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counter int
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breakTimestamp time.Time
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}
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)
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var ErrCBClosed = errors.New("circuit breaker is closed")
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func newCircuitBreaker(breakDuration time.Duration, threshold int) *circuitBreaker {
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return &circuitBreaker{
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breakDuration: breakDuration,
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threshold: threshold,
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state: make(map[uint64]state),
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}
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}
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func (c *circuitBreaker) Do(id uint64, f func() error) error {
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c.mu.Lock()
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defer c.mu.Unlock()
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if _, ok := c.state[id]; !ok {
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c.state[id] = state{}
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}
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s := c.state[id]
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defer func() {
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c.state[id] = s
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}()
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if time.Since(s.breakTimestamp) < c.breakDuration {
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return ErrCBClosed
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}
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err := f()
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if err == nil {
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s.counter = 0
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return nil
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}
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s.counter++
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if s.counter >= c.threshold {
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s.counter = c.threshold
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s.breakTimestamp = time.Now()
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}
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return err
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}
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