package bounded_tree import ( "sync" "github.com/chrislusf/seaweedfs/weed/glog" "github.com/chrislusf/seaweedfs/weed/util" ) type Node struct { Parent *Node Name string Children map[string]*Node } type BoundedTree struct { root *Node sync.RWMutex baseDir util.FullPath } func NewBoundedTree(baseDir util.FullPath) *BoundedTree { return &BoundedTree{ root: &Node{ Name: "/", }, baseDir: baseDir, } } type VisitNodeFunc func(path util.FullPath) (childDirectories []string, err error) // If the path is not visited, call the visitFn for each level of directory // No action if the directory has been visited before or does not exist. // A leaf node, which has no children, represents a directory not visited. // A non-leaf node or a non-existing node represents a directory already visited, or does not need to visit. func (t *BoundedTree) EnsureVisited(p util.FullPath, visitFn VisitNodeFunc) (visitErr error) { t.Lock() defer t.Unlock() if t.root == nil { return } components := util.FullPath(p[len(t.baseDir):]).Split() // fmt.Printf("components %v %d\n", components, len(components)) canDelete, err := t.ensureVisited(t.root, t.baseDir, components, 0, visitFn) if err != nil { return err } if canDelete { t.root = nil } return nil } func (t *BoundedTree) ensureVisited(n *Node, currentPath util.FullPath, components []string, i int, visitFn VisitNodeFunc) (canDeleteNode bool, visitErr error) { // println("ensureVisited", currentPath, i) if n == nil { // fmt.Printf("%s null\n", currentPath) return } if n.isVisited() { // fmt.Printf("%s visited %v\n", currentPath, n.Name) } else { // fmt.Printf("ensure %v\n", currentPath) children, err := visitFn(currentPath) if err != nil { glog.V(0).Infof("failed to visit %s: %v", currentPath, err) return false, err } if len(children) == 0 { // fmt.Printf(" canDelete %v without children\n", currentPath) return true, nil } n.Children = make(map[string]*Node) for _, child := range children { // fmt.Printf(" add child %v %v\n", currentPath, child) n.Children[child] = &Node{ Name: child, } } } if i >= len(components) { return } // fmt.Printf(" check child %v %v\n", currentPath, components[i]) toVisitNode, found := n.Children[components[i]] if !found { // fmt.Printf(" did not find child %v %v\n", currentPath, components[i]) return } // fmt.Printf(" ensureVisited %v %v\n", currentPath, toVisitNode.Name) canDelete, childVisitErr := t.ensureVisited(toVisitNode, currentPath.Child(components[i]), components, i+1, visitFn) if childVisitErr != nil { return false, childVisitErr } if canDelete { // fmt.Printf(" delete %v %v\n", currentPath, components[i]) delete(n.Children, components[i]) if len(n.Children) == 0 { // fmt.Printf(" canDelete %v\n", currentPath) return true, nil } } return false, nil } func (n *Node) isVisited() bool { if n == nil { return true } if len(n.Children) > 0 { return true } return false } func (n *Node) getChild(childName string) *Node { if n == nil { return nil } if len(n.Children) > 0 { return n.Children[childName] } return nil } func (t *BoundedTree) HasVisited(p util.FullPath) bool { t.RLock() defer t.RUnlock() if t.root == nil { return true } components := p.Split() // fmt.Printf("components %v %d\n", components, len(components)) return t.hasVisited(t.root, util.FullPath("/"), components, 0) } func (t *BoundedTree) hasVisited(n *Node, currentPath util.FullPath, components []string, i int) bool { if n == nil { return true } if !n.isVisited() { return false } // fmt.Printf(" hasVisited child %v %+v %d\n", currentPath, components, i) if i >= len(components) { return true } toVisitNode, found := n.Children[components[i]] if !found { return true } return t.hasVisited(toVisitNode, currentPath.Child(components[i]), components, i+1) }