func (eb backoff) beginAttempt(retryKey string) (int, error) {
conn, err := goworker.GetConn()
if err != nil {
return -1, err
}
defer goworker.PutConn(conn)
// Create the retry key if not exists
_, err = conn.Do("SETNX", retryKey, -1)
if err != nil {
return -1, err
}
// Increment the attempt we're on
retryAttempt, err := redis.Int(conn.Do("INCR", retryKey))
if err != nil {
return -1, err
}
// Expire the retry key so we don't leave it hanging
// (an hour after it was supposed to be removed)
conn.Do("EXPIRE", retryKey, eb.retryDelay(retryAttempt)+3600)
return retryAttempt, nil
}
func (eb backoff) WorkerFunc() func(string, ...interface{}) error {
return func(queue string, args ...interface{}) error {
retryKey := eb.retryKey(args)
// Setup the attempt
retryAttempt, err := eb.beginAttempt(retryKey)
if err != nil {
return err
}
// Run the job
workerErr := eb.worker(queue, args...)
// Get redis connection
conn, err := goworker.GetConn()
if err != nil {
return err
}
defer goworker.PutConn(conn)
// Success, just clear the retry key
if workerErr == nil {
conn.Do("DEL", retryKey)
return nil
}
if retryAttempt >= eb.RetryLimit {
// If we've retried too many times, give up
conn.Do("DEL", retryKey)
} else {
// Otherwise schedule the retry attempt
seconds := eb.retryDelay(retryAttempt)
if seconds <= 0 {
// If there's no delay, just enqueue it
_, err = resque.Enqueue(conn.Conn, queue, eb.jobName, args...)
} else {
// Otherwise schedule it
delay := time.Duration(seconds) * time.Second
err = resque.EnqueueIn(conn.Conn, delay, queue, eb.jobName, args...)
}
if err != nil {
return err
}
}
// Wrap the error
return fmt.Errorf("retry: attempt %d of %d failed: %s", retryAttempt, eb.RetryLimit, workerErr.Error())
}
}