Method CAS

kv/client.go:118–118

CAS stands for Compare-And-Swap. Will call provided callback f with the current value of the key and allow callback to return a different value. Will then attempt to atomically swap the current value for the new value. If that doesn't succeed will try again - callback will be called again with new v

(ctx context.Context, key string, f func(in interface{}) (out interface{}, retry bool, err error))

	// If the callback returns an error and true for retry, and the max number of
	// attempts is not exceeded, the operation will be retried.
	CAS(ctx context.Context, key string, f func(in interface{}) (out interface{}, retry bool, err error)) error

	// WatchKey calls f whenever the value stored under key changes.
	WatchKey(ctx context.Context, key string, f func(interface{}) bool)