// Copyright (c) 2014-2015 The Notify Authors. All rights reserved.
// Use of this source code is governed by the MIT license that can be
// found in the LICENSE file.
package notify
import (
"errors"
"io/ioutil"
"os"
"path/filepath"
)
var errSkip = errors.New("notify: skip")
type walkPathFunc func(nd node, isbase bool) error
type walkFunc func(node) error
func errnotexist(name string) error {
return &os.PathError{
Op: "Node",
Path: name,
Err: os.ErrNotExist,
}
}
type node struct {
Name string
Watch watchpoint
Child map[string]node
}
func newnode(name string) node {
return node{
Name: name,
Watch: make(watchpoint),
Child: make(map[string]node),
}
}
func (nd node) addchild(name, base string) node {
child, ok := nd.Child[base]
if !ok {
child = newnode(name)
nd.Child[base] = child
}
return child
}
func (nd node) Add(name string) node {
i := indexbase(nd.Name, name)
if i == -1 {
return node{}
}
for j := indexSep(name[i:]); j != -1; j = indexSep(name[i:]) {
nd = nd.addchild(name[:i+j], name[i:i+j])
i += j + 1
}
return nd.addchild(name, name[i:])
}
func (nd node) AddDir(fn walkFunc) error {
stack := []node{nd}
Traverse:
for n := len(stack); n != 0; n = len(stack) {
nd, stack = stack[n-1], stack[:n-1]
switch err := fn(nd); err {
case nil:
case errSkip:
continue Traverse
default:
return &os.PathError{
Op: "error while traversing",
Path: nd.Name,
Err: err,
}
}
// TODO(rjeczalik): tolerate open failures - add failed names to
// AddDirError and notify users which names are not added to the tree.
fi, err := ioutil.ReadDir(nd.Name)
if err != nil {
return err
}
for _, fi := range fi {
if fi.Mode()&(os.ModeSymlink|os.ModeDir) == os.ModeDir {
name := filepath.Join(nd.Name, fi.Name())
stack = append(stack, nd.addchild(name, name[len(nd.Name)+1:]))
}
}
}
return nil
}
func (nd node) Get(name string) (node, error) {
i := indexbase(nd.Name, name)
if i == -1 {
return node{}, errnotexist(name)
}
ok := false
for j := indexSep(name[i:]); j != -1; j = indexSep(name[i:]) {
if nd, ok = nd.Child[name[i:i+j]]; !ok {
return node{}, errnotexist(name)
}
i += j + 1
}
if nd, ok = nd.Child[name[i:]]; !ok {
return node{}, errnotexist(name)
}
return nd, nil
}
func (nd node) Del(name string) error {
i := indexbase(nd.Name, name)
if i == -1 {
return errnotexist(name)
}
stack := []node{nd}
ok := false
for j := indexSep(name[i:]); j != -1; j = indexSep(name[i:]) {
if nd, ok = nd.Child[name[i:i+j]]; !ok {
return errnotexist(name[:i+j])
}
stack = append(stack, nd)
}
if nd, ok = nd.Child[name[i:]]; !ok {
return errnotexist(name)
}
nd.Child = nil
nd.Watch = nil
for name, i = base(nd.Name), len(stack); i != 0; name, i = base(nd.Name), i-1 {
nd = stack[i-1]
if nd := nd.Child[name]; len(nd.Watch) > 1 || len(nd.Child) != 0 {
break
} else {
nd.Child = nil
nd.Watch = nil
}
delete(nd.Child, name)
}
return nil
}
func (nd node) Walk(fn walkFunc) error {
stack := []node{nd}
Traverse:
for n := len(stack); n != 0; n = len(stack) {
nd, stack = stack[n-1], stack[:n-1]
switch err := fn(nd); err {
case nil:
case errSkip:
continue Traverse
default:
return err
}
for name, nd := range nd.Child {
if name == "" {
// Node storing inactive watchpoints has empty name, skip it
// form traversing. Root node has also an empty name, but it
// never has a parent node.
continue
}
stack = append(stack, nd)
}
}
return nil
}
func (nd node) WalkPath(name string, fn walkPathFunc) error {
i := indexbase(nd.Name, name)
if i == -1 {
return errnotexist(name)
}
ok := false
for j := indexSep(name[i:]); j != -1; j = indexSep(name[i:]) {
switch err := fn(nd, false); err {
case nil:
case errSkip:
return nil
default:
return err
}
if nd, ok = nd.Child[name[i:i+j]]; !ok {
return errnotexist(name[:i+j])
}
i += j + 1
}
switch err := fn(nd, false); err {
case nil:
case errSkip:
return nil
default:
return err
}
if nd, ok = nd.Child[name[i:]]; !ok {
return errnotexist(name)
}
switch err := fn(nd, true); err {
case nil, errSkip:
return nil
default:
return err
}
}
type root struct {
nd node
}
func (r root) addroot(name string) node {
if vol := filepath.VolumeName(name); vol != "" {
root, ok := r.nd.Child[vol]
if !ok {
root = r.nd.addchild(vol, vol)
}
return root
}
return r.nd
}
func (r root) root(name string) (node, error) {
if vol := filepath.VolumeName(name); vol != "" {
nd, ok := r.nd.Child[vol]
if !ok {
return node{}, errnotexist(name)
}
return nd, nil
}
return r.nd, nil
}
func (r root) Add(name string) node {
return r.addroot(name).Add(name)
}
func (r root) AddDir(dir string, fn walkFunc) error {
return r.Add(dir).AddDir(fn)
}
func (r root) Del(name string) error {
nd, err := r.root(name)
if err != nil {
return err
}
return nd.Del(name)
}
func (r root) Get(name string) (node, error) {
nd, err := r.root(name)
if err != nil {
return node{}, err
}
if nd.Name != name {
if nd, err = nd.Get(name); err != nil {
return node{}, err
}
}
return nd, nil
}
func (r root) Walk(name string, fn walkFunc) error {
nd, err := r.Get(name)
if err != nil {
return err
}
return nd.Walk(fn)
}
func (r root) WalkPath(name string, fn walkPathFunc) error {
nd, err := r.root(name)
if err != nil {
return err
}
return nd.WalkPath(name, fn)
}
