backoff_example_test.go

Documentation: github.com/lestrrat-go/backoff/v2

     1  package backoff_test
     2  
     3  import (
     4  	"context"
     5  	"errors"
     6  	"time"
     7  
     8  	backoff "github.com/lestrrat-go/backoff/v2"
     9  )
    10  
    11  func ExampleConstant() {
    12  	p := backoff.Constant(backoff.WithInterval(time.Second))
    13  
    14  	flakyFunc := func(a int) (int, error) {
    15  		// silly function that only succeeds if the current call count is
    16  		// divisible by either 3 or 5 but not both
    17  		switch {
    18  		case a%15 == 0:
    19  			return 0, errors.New(`invalid`)
    20  		case a%3 == 0 || a%5 == 0:
    21  			return a, nil
    22  		}
    23  		return 0, errors.New(`invalid`)
    24  	}
    25  
    26  	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
    27  	defer cancel()
    28  
    29  	retryFunc := func(v int) (int, error) {
    30  		b := p.Start(ctx)
    31  		for backoff.Continue(b) {
    32  			x, err := flakyFunc(v)
    33  			if err == nil {
    34  				return x, nil
    35  			}
    36  		}
    37  		return 0, errors.New(`failed to get value`)
    38  	}
    39  
    40  	retryFunc(15)
    41  }
    42  
    43  func ExampleExponential() {
    44  	p := backoff.Exponential(
    45  		backoff.WithMinInterval(time.Second),
    46  		backoff.WithMaxInterval(time.Minute),
    47  		backoff.WithJitterFactor(0.05),
    48  	)
    49  
    50  	flakyFunc := func(a int) (int, error) {
    51  		// silly function that only succeeds if the current call count is
    52  		// divisible by either 3 or 5 but not both
    53  		switch {
    54  		case a%15 == 0:
    55  			return 0, errors.New(`invalid`)
    56  		case a%3 == 0 || a%5 == 0:
    57  			return a, nil
    58  		}
    59  		return 0, errors.New(`invalid`)
    60  	}
    61  
    62  	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
    63  	defer cancel()
    64  
    65  	retryFunc := func(v int) (int, error) {
    66  		b := p.Start(ctx)
    67  		for backoff.Continue(b) {
    68  			x, err := flakyFunc(v)
    69  			if err == nil {
    70  				return x, nil
    71  			}
    72  		}
    73  		return 0, errors.New(`failed to get value`)
    74  	}
    75  
    76  	retryFunc(15)
    77  }
    78
View as plain text