blob: 445131caee596ff3fe323c720557c4075455a982 [file] [log] [blame]
package metrics
// Healthchecks hold an error value describing an arbitrary up/down status.
type Healthcheck interface {
Error() error
// NewHealthcheck constructs a new Healthcheck which will use the given
// function to update its status.
func NewHealthcheck(f func(Healthcheck)) Healthcheck {
if UseNilMetrics {
return NilHealthcheck{}
return &StandardHealthcheck{nil, f}
// NilHealthcheck is a no-op.
type NilHealthcheck struct{}
// Check is a no-op.
func (NilHealthcheck) Check() {}
// Error is a no-op.
func (NilHealthcheck) Error() error { return nil }
// Healthy is a no-op.
func (NilHealthcheck) Healthy() {}
// Unhealthy is a no-op.
func (NilHealthcheck) Unhealthy(error) {}
// StandardHealthcheck is the standard implementation of a Healthcheck and
// stores the status and a function to call to update the status.
type StandardHealthcheck struct {
err error
f func(Healthcheck)
// Check runs the healthcheck function to update the healthcheck's status.
func (h *StandardHealthcheck) Check() {
// Error returns the healthcheck's status, which will be nil if it is healthy.
func (h *StandardHealthcheck) Error() error {
return h.err
// Healthy marks the healthcheck as healthy.
func (h *StandardHealthcheck) Healthy() {
h.err = nil
// Unhealthy marks the healthcheck as unhealthy. The error is stored and
// may be retrieved by the Error method.
func (h *StandardHealthcheck) Unhealthy(err error) {
h.err = err