The application relates to
electronic data processing of
engineering cost, and discloses a method for sharing and canceling nodes in the scope of
engineering cost equivalence request. A processor parses a candidate variable into a normalized scope semantic tuple containing a project version, a hierarchical node range, a
source field path, filtering, aggregation, transformation, a unit of measurement and precision, to request a summary to locate a sharing bucket, and compare complete tuples in the bucket, and only merge requests that are completely equivalent in
semantics, have certainty and have no external side effects. A shared node maintains a node
generation number and an active candidate reference set; when a candidate is canceled, only the reference is removed; only when the reference is empty, the node is to be executed and the generation numbers match, the node is canceled. A node executes a snapshot of an immutable variable once, writes a barrier to prevent distribution to canceled candidates, and invalidates affected nodes according to a change set, so that range missharing, cross-candidate cancellation interference and old snapshot reuse are avoided.