Techniques for graph data structure management. In one aspect, a data structure includes a plurality of nodes connected by edges. A node of the data structure includes a current set of variables for defining a state of the node and at least one last-in, first-out stack for storing pointers to prior sets of variables for the node. The state of the node may be saved by adding a pointer to at least one of the stacks at the node. The state of the node may be restored by removing the pointer from the stack and restoring the node variables to those indicated by the pointer. A first counter associated with a stack at the node may store a number of pending saves at the node, while a second counter may store a number of saves to be propagated to descendents of the node. A state of the data structure may be saved by traversing other nodes of the data structure and adding pointers or incrementing counters at the nodes.