error.go

package loadingcache

import (
	"fmt"
	"time"
)

// LoadingError is an interface which extends the default error type to also provide a method
// on how long this error should be cached for.
type LoadingError interface {
	error
	CacheFor() time.Duration
}

type loadingError struct {
	error
	ttl time.Duration
}

func (e loadingError) CacheFor() time.Duration {
	return e.ttl
}

// Errorf is a function which instantiates a new error abiding by the LoadingError interface.
// Use this when you want a "tombstone" value to be created inside of the cache, specifying how long
// the tombstone should be valid for.
func Errorf(t time.Duration, f string, args ...any) LoadingError {
	return loadingError{
		error: fmt.Errorf(f, args...),
		ttl:   t,
	}
}