mirror of
https://github.com/chrislusf/seaweedfs
synced 2024-09-06 09:00:34 +02:00
188 lines
4 KiB
Go
188 lines
4 KiB
Go
package bounded_tree
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import (
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"sync"
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"github.com/chrislusf/seaweedfs/weed/glog"
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"github.com/chrislusf/seaweedfs/weed/util"
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)
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type Node struct {
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Parent *Node
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Name string
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Children map[string]*Node
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}
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type BoundedTree struct {
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root *Node
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sync.RWMutex
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baseDir util.FullPath
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}
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func NewBoundedTree(baseDir util.FullPath) *BoundedTree {
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return &BoundedTree{
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root: &Node{
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Name: "/",
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},
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baseDir: baseDir,
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}
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}
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type VisitNodeFunc func(path util.FullPath) (childDirectories []string, err error)
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// If the path is not visited, call the visitFn for each level of directory
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// No action if the directory has been visited before or does not exist.
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// A leaf node, which has no children, represents a directory not visited.
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// A non-leaf node or a non-existing node represents a directory already visited, or does not need to visit.
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func (t *BoundedTree) EnsureVisited(p util.FullPath, visitFn VisitNodeFunc) (visitErr error) {
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t.Lock()
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defer t.Unlock()
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if t.root == nil {
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return
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}
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if t.baseDir != "/" {
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p = p[len(t.baseDir):]
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}
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components := p.Split()
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// fmt.Printf("components %v %d\n", components, len(components))
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canDelete, err := t.ensureVisited(t.root, t.baseDir, components, 0, visitFn)
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if err != nil {
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return err
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}
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if canDelete {
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t.root = nil
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}
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return nil
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}
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func (t *BoundedTree) ensureVisited(n *Node, currentPath util.FullPath, components []string, i int, visitFn VisitNodeFunc) (canDeleteNode bool, visitErr error) {
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// println("ensureVisited", currentPath, i)
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if n == nil {
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// fmt.Printf("%s null\n", currentPath)
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return
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}
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if n.isVisited() {
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// fmt.Printf("%s visited %v\n", currentPath, n.Name)
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} else {
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// fmt.Printf("ensure %v\n", currentPath)
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filerPath := currentPath
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if t.baseDir != "/" {
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filerPath = t.baseDir + filerPath
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}
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children, err := visitFn(filerPath)
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if err != nil {
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glog.V(0).Infof("failed to visit %s: %v", currentPath, err)
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return false, err
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}
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if len(children) == 0 {
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// fmt.Printf(" canDelete %v without children\n", currentPath)
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return true, nil
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}
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n.Children = make(map[string]*Node)
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for _, child := range children {
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// fmt.Printf(" add child %v %v\n", currentPath, child)
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n.Children[child] = &Node{
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Name: child,
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}
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}
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}
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if i >= len(components) {
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return
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}
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// fmt.Printf(" check child %v %v\n", currentPath, components[i])
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toVisitNode, found := n.Children[components[i]]
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if !found {
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// fmt.Printf(" did not find child %v %v\n", currentPath, components[i])
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return
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}
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// fmt.Printf(" ensureVisited %v %v\n", currentPath, toVisitNode.Name)
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canDelete, childVisitErr := t.ensureVisited(toVisitNode, currentPath.Child(components[i]), components, i+1, visitFn)
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if childVisitErr != nil {
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return false, childVisitErr
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}
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if canDelete {
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// fmt.Printf(" delete %v %v\n", currentPath, components[i])
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delete(n.Children, components[i])
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if len(n.Children) == 0 {
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// fmt.Printf(" canDelete %v\n", currentPath)
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return true, nil
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}
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}
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return false, nil
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}
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func (n *Node) isVisited() bool {
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if n == nil {
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return true
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}
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if len(n.Children) > 0 {
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return true
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}
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return false
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}
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func (n *Node) getChild(childName string) *Node {
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if n == nil {
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return nil
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}
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if len(n.Children) > 0 {
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return n.Children[childName]
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}
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return nil
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}
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func (t *BoundedTree) HasVisited(p util.FullPath) bool {
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t.RLock()
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defer t.RUnlock()
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if t.root == nil {
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return true
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}
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components := p.Split()
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// fmt.Printf("components %v %d\n", components, len(components))
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return t.hasVisited(t.root, util.FullPath("/"), components, 0)
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}
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func (t *BoundedTree) hasVisited(n *Node, currentPath util.FullPath, components []string, i int) bool {
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if n == nil {
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return true
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}
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if !n.isVisited() {
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return false
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}
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// fmt.Printf(" hasVisited child %v %+v %d\n", currentPath, components, i)
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if i >= len(components) {
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return true
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}
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toVisitNode, found := n.Children[components[i]]
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if !found {
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return true
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}
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return t.hasVisited(toVisitNode, currentPath.Child(components[i]), components, i+1)
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}
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