github.com/cloudreve/Cloudreve/v3@v3.0.0-20240224133659-3edb00a6484c/pkg/filesystem/chunk/backoff/backoff.go (about)

     1  package backoff
     2  
     3  import (
     4  	"errors"
     5  	"fmt"
     6  	"github.com/cloudreve/Cloudreve/v3/pkg/util"
     7  	"net/http"
     8  	"strconv"
     9  	"time"
    10  )
    11  
    12  // Backoff used for retry sleep backoff
    13  type Backoff interface {
    14  	Next(err error) bool
    15  	Reset()
    16  }
    17  
    18  // ConstantBackoff implements Backoff interface with constant sleep time. If the error
    19  // is retryable and with `RetryAfter` defined, the `RetryAfter` will be used as sleep duration.
    20  type ConstantBackoff struct {
    21  	Sleep time.Duration
    22  	Max   int
    23  
    24  	tried int
    25  }
    26  
    27  func (c *ConstantBackoff) Next(err error) bool {
    28  	c.tried++
    29  	if c.tried > c.Max {
    30  		return false
    31  	}
    32  
    33  	var e *RetryableError
    34  	if errors.As(err, &e) && e.RetryAfter > 0 {
    35  		util.Log().Warning("Retryable error %q occurs in backoff, will sleep after %s.", e, e.RetryAfter)
    36  		time.Sleep(e.RetryAfter)
    37  	} else {
    38  		time.Sleep(c.Sleep)
    39  	}
    40  
    41  	return true
    42  }
    43  
    44  func (c *ConstantBackoff) Reset() {
    45  	c.tried = 0
    46  }
    47  
    48  type RetryableError struct {
    49  	Err        error
    50  	RetryAfter time.Duration
    51  }
    52  
    53  // NewRetryableErrorFromHeader constructs a new RetryableError from http response header
    54  // and existing error.
    55  func NewRetryableErrorFromHeader(err error, header http.Header) *RetryableError {
    56  	retryAfter := header.Get("retry-after")
    57  	if retryAfter == "" {
    58  		retryAfter = "0"
    59  	}
    60  
    61  	res := &RetryableError{
    62  		Err: err,
    63  	}
    64  
    65  	if retryAfterSecond, err := strconv.ParseInt(retryAfter, 10, 64); err == nil {
    66  		res.RetryAfter = time.Duration(retryAfterSecond) * time.Second
    67  	}
    68  
    69  	return res
    70  }
    71  
    72  func (e *RetryableError) Error() string {
    73  	return fmt.Sprintf("retryable error with retry-after=%s: %s", e.RetryAfter, e.Err)
    74  }