44 lines
		
	
	
		
			890 B
		
	
	
	
		
			Go
		
	
	
	
			
		
		
	
	
			44 lines
		
	
	
		
			890 B
		
	
	
	
		
			Go
		
	
	
	
package retryutil
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import (
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	"fmt"
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	"time"
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)
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type RetryError struct {
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	n int
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}
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func (e *RetryError) Error() string {
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	return fmt.Sprintf("still failing after %d retries", e.n)
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}
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type ConditionFunc func() (bool, error)
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// Retry retries f every interval until after maxRetries.
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// The interval won't be affected by how long f takes.
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// For example, if interval is 3s, f takes 1s, another f will be called 2s later.
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// However, if f takes longer than interval, it will be delayed.
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func Retry(interval time.Duration, maxRetries int, f ConditionFunc) error {
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	if maxRetries <= 0 {
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		return fmt.Errorf("maxRetries (%d) should be > 0", maxRetries)
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	}
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	tick := time.NewTicker(interval)
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	defer tick.Stop()
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	for i := 0; ; i++ {
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		ok, err := f()
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		if err != nil {
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			return err
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		}
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		if ok {
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			return nil
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		}
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		if i+1 == maxRetries {
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			break
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		}
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		<-tick.C
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	}
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	return &RetryError{maxRetries}
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}
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