Method FindOrInsertNode

internal/graph/graph.go:234–265

FindOrInsertNode takes the info for a node and either returns a matching node from the node map if one exists, or adds one to the map if one does not. If kept is non-nil, nodes are only added if they can be located on it.

(info NodeInfo, kept NodeSet)

// from the node map if one exists, or adds one to the map if one does not.
// If kept is non-nil, nodes are only added if they can be located on it.
func (nm NodeMap) FindOrInsertNode(info NodeInfo, kept NodeSet) *Node {
	if kept != nil {
		if _, ok := kept[info]; !ok {
			return nil
		}
	}

	if n, ok := nm[info]; ok {
		return n
	}

	n := &Node{
		Info:        info,
		In:          make(EdgeMap),
		Out:         make(EdgeMap),
		LabelTags:   make(TagMap),
		NumericTags: make(map[string]TagMap),
	}
	nm[info] = n
	if info.Address == 0 && info.Lineno == 0 {
		// This node represents the whole function, so point Function
		// back to itself.
		n.Function = n
		return n
	}
	// Find a node that represents the whole function.
	info.Address = 0
	info.Lineno = 0
	info.Columnno = 0
	n.Function = nm.FindOrInsertNode(info, nil)
	return n
}

// EdgeMap is used to represent the incoming/outgoing edges from a node.
type EdgeMap map[*Node]*Edge