perkeep/third_party/code.google.com/p/rsc/fuse/tree.go

94 lines
1.8 KiB
Go

// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// FUSE directory tree, for servers that wish to use it with the service loop.
package fuse
import (
"os"
pathpkg "path"
"strings"
)
// A Tree implements a basic directory tree for FUSE.
type Tree struct {
tree
}
func (t *Tree) Root() (Node, Error) {
return &t.tree, nil
}
// Add adds the path to the tree, resolving to the given node.
// If path or a prefix of path has already been added to the tree,
// Add panics.
func (t *Tree) Add(path string, node Node) {
path = pathpkg.Clean("/" + path)[1:]
elems := strings.Split(path, "/")
dir := Node(&t.tree)
for i, elem := range elems {
dt, ok := dir.(*tree)
if !ok {
panic("fuse: Tree.Add for " + strings.Join(elems[:i], "/") + " and " + path)
}
n := dt.lookup(elem)
if n != nil {
if i+1 == len(elems) {
panic("fuse: Tree.Add for " + path + " conflicts with " + elem)
}
dir = n
} else {
if i+1 == len(elems) {
dt.add(elem, node)
} else {
dir = &tree{}
dt.add(elem, dir)
}
}
}
}
type treeDir struct {
name string
node Node
}
type tree struct {
dir []treeDir
}
func (t *tree) lookup(name string) Node {
for _, d := range t.dir {
if d.name == name {
return d.node
}
}
return nil
}
func (t *tree) add(name string, n Node) {
t.dir = append(t.dir, treeDir{name, n})
}
func (t *tree) Attr() Attr {
return Attr{Mode: os.ModeDir | 0555}
}
func (t *tree) Lookup(name string, intr Intr) (Node, Error) {
n := t.lookup(name)
if n != nil {
return n, nil
}
return nil, ENOENT
}
func (t *tree) ReadDir(intr Intr) ([]Dirent, Error) {
var out []Dirent
for _, d := range t.dir {
out = append(out, Dirent{Name: d.name})
}
return out, nil
}