How to access past state?

[vwkd]

How do we access past state? How do we access direct state or accumulated state, for a certain point in time or a duration in time?

Golem likely stores the sequence of input/output calls of a component since time 0 to be able to restore its present state by replaying them. To access direct state for a certain point in time, Golem could offer an API to create a new temporary component with replayed component state until time t that can then be called. But doing this for every point in time over a duration seems to be inefficient. Also, for accumulated state we would need to push the calculation to the client which could be error prone. For example, calculate the total incoming/outgoing cash flow over a duration by summing the cash account balance at each point in time over the duration.

This would work for state components that store the state internally. But what for workflow components where state are the executions itself? For example, the number of fulfilled orders is the number of successful executions of the order component. Golem likely doesn't store this history directly.