README
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Documentation
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Overview ¶
Package retry please refer to README.md
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
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var ErrAttemptsExceeded = errors.New("exceeded max attempts")
ErrAttemptsExceeded is returned when we exceeded the max attempts without succeeding
Functions ¶
This section is empty.
Types ¶
type Client ¶
type Client struct {
// MaxAttempts is the maximum number of retry attempts before giving up. (default: 3)
MaxAttempts int
// BaseDelay is the base amount of time between attempts (default: 10 ms)
BaseDelay time.Duration
// MaxDelay is the maximum possible delay (default: 1 second)
MaxDelay time.Duration
// CanRetry allows for selectively shortcutting the retries.
// Useful for cases were retrying would never work. (default: retry always)
CanRetry func(error) bool
// IsIgnored allows for selectively ignoring some errors (from tracking) but still returning the error.
// Useful for things like ignoring a HTTP404 when that is not an error
IsIgnored func(error) bool
// MetricsClient allows this package to emit metrics (default: no metrics)
Metrics MetricsClient
}
Client implements the Exponential Backoff
func (*Client) Do ¶
Do executes the lambda until success, context is cancelled, attempts are exceeded or a fatal error.
Example ¶
package main
import (
"context"
"fmt"
"time"
"github.com/corsc/go-commons/resilience/retry"
)
func main() {
// simplest usage; using the defaults
ctx, cancelFunc := context.WithTimeout(context.Background(), 5*time.Second)
defer cancelFunc()
err := (&retry.Client{}).Do(ctx, "myretry", func() error {
// do something amazing here
return nil
})
fmt.Printf("error was %v", err)
}
Output: error was <nil>
Example (CustomErrorHandling) ¶
package main
import (
"context"
"errors"
"fmt"
"net/http"
"time"
"github.com/corsc/go-commons/resilience/retry"
)
func main() {
// some custom errors
var ErrUserError = errors.New("bad user input - retrying won't help")
var ErrNetworkError = errors.New("bad connection - retrying might help")
ctx, cancelFunc := context.WithTimeout(context.Background(), 5*time.Second)
defer cancelFunc()
client := &retry.Client{
CanRetry: func(err error) bool {
if err == ErrUserError {
return false
}
if err == ErrNetworkError {
return true
}
return true
},
}
err := client.Do(ctx, "myretry", func() error {
resp, err := http.Get("http://www.google.com/")
if err != nil {
// pass HTTP client errors out
return err
}
// convert response codes into errors (where appropriate)
switch resp.StatusCode {
case http.StatusOK:
return nil
case http.StatusBadRequest:
return ErrUserError
case http.StatusBadGateway:
return ErrNetworkError
}
return nil
})
fmt.Printf("error was %v", err)
}
Output: error was <nil>
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