singleflight

func (*Group[K, V]) Do ¶

func (g *Group[K, V]) Do(key K, fn func() (V, error)) (v V, err error, shared bool)

Do executes and returns the results of the given function, making sure that only one execution is in-flight for a given key at a time. If a duplicate comes in, the duplicate caller waits for the original to complete and receives the same results. The return value shared indicates whether v was given to multiple callers.

func (*Group[K, V]) DoChan ¶

func (g *Group[K, V]) DoChan(key K, fn func() (V, error)) <-chan Result[V]

DoChan is like Do but returns a channel that will receive the results when they are ready.

The returned channel will not be closed.

func (*Group[K, V]) DoContext ¶

func (g *Group[K, V]) DoContext(ctx context.Context, key K, fn func() (V, error)) (v V, err error, shared bool)

DoContext is like Do but respects context cancellation. If the context is cancelled, it returns the context error immediately. The underlying function will still complete, but this caller won't wait for it.

func (*Group[K, V]) Forget ¶

func (g *Group[K, V]) Forget(key K)

Forget tells the singleflight to forget about a key. Future calls to Do for this key will call the function rather than waiting for an earlier call to complete.

func (*Group[K, V]) InFlight ¶

func (g *Group[K, V]) InFlight() int

InFlight returns the number of keys currently being processed.