gotools/gopls/internal/cache/future.go

type futureCache …

// newFutureCache returns a futureCache that is ready to coordinate
// computations via [futureCache.get].
//
// If persistent is true, the results of these computations are stored for the
// lifecycle of cache. Otherwise, results are discarded after they have been
// passed to all awaiting goroutines.
func newFutureCache[K comparable, V any](persistent bool) *futureCache[K, V] { … }

type future …

type cacheFunc …

// get retrieves or computes the value corresponding to k.
//
// If the cache if persistent and the value has already been computed, get
// returns the result of the previous computation. Otherwise, get either starts
// a computation or joins an ongoing computation. If that computation is
// cancelled, get will reassign the computation to a new goroutine as long as
// there are awaiters.
//
// Once the computation completes, the result is passed to all awaiting
// goroutines. If the cache is transient (persistent=false), the corresponding
// cache entry is removed, and the next call to get will execute a new
// computation.
//
// It is therefore the responsibility of the caller to ensure that the given
// compute function is safely retryable, and always returns the same value.
func (c *futureCache[K, V]) get(ctx context.Context, k K, compute cacheFunc[V]) (V, error) { … }