255 lines
5.6 KiB
Go
255 lines
5.6 KiB
Go
/*
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* Copyright (c) 2015 Alex Yatskov <alex@foosoft.net>
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* Author: Alex Yatskov <alex@foosoft.net>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy of
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* this software and associated documentation files (the "Software"), to deal in
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* the Software without restriction, including without limitation the rights to
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* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
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* the Software, and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
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* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
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* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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package main
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import (
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"bazil.org/fuse"
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"bazil.org/fuse/fs"
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"encoding/json"
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"fmt"
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"golang.org/x/net/context"
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"io/ioutil"
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"os"
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"path/filepath"
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"regexp"
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"strconv"
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"time"
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)
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type versionMetadata struct {
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Deleted []string
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}
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type versionedNode struct {
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path string
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info os.FileInfo
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}
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type versionedFile struct {
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node versionedNode
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inode uint64
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}
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func (this versionedFile) Attr(attr *fuse.Attr) {
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attr.Mode = this.node.info.Mode()
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attr.Inode = this.inode
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attr.Size = uint64(this.node.info.Size())
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}
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func (versionedFile) ReadAll(ctx context.Context) ([]byte, error) {
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return nil, nil
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}
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type versionedDir struct {
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dirs map[string]versionedDir
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files map[string]versionedFile
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node versionedNode
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inode uint64
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}
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func (this versionedDir) Attr(attr *fuse.Attr) {
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attr.Mode = this.node.info.Mode()
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attr.Inode = this.inode
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}
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func (this versionedDir) ReadDirAll(ctx context.Context) ([]fuse.Dirent, error) {
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var entries []fuse.Dirent
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for name, dir := range this.dirs {
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entry := fuse.Dirent{Inode: dir.inode, Name: name, Type: fuse.DT_File}
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entries = append(entries, entry)
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}
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for name, file := range this.files {
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entry := fuse.Dirent{Inode: file.inode, Name: name, Type: fuse.DT_Dir}
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entries = append(entries, entry)
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}
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return nil, nil
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}
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func (this versionedDir) Lookup(ctx context.Context, name string) (fs.Node, error) {
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if dir, ok := this.dirs[name]; ok {
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return dir, nil
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}
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if file, ok := this.files[name]; ok {
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return file, nil
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}
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return nil, fuse.ENOENT
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}
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type version struct {
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base string
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parent *version
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timestamp time.Time
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meta versionMetadata
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root versionedDir
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inodeCnt uint64
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}
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func newVersion(base string, parent *version) (*version, error) {
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re, err := regexp.Compile(`/vfs_([0-9a-f])$`)
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if err != nil {
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return nil, err
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}
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matches := re.FindStringSubmatch(base)
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if len(matches) < 2 {
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return nil, fmt.Errorf("invalid version identifier for %s", base)
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}
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timeval, err := strconv.ParseInt(matches[1], 16, 64)
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if err != nil {
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return nil, err
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}
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ver := &version{
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base: base,
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parent: parent,
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timestamp: time.Unix(timeval, 0)}
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if err := ver.loadMetadata(); err != nil {
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return nil, err
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}
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if err := ver.scanFs(); err != nil {
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return nil, err
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}
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return ver, nil
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}
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func (this *version) scanDir(path string) (map[string]versionedNode, error) {
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ownNodes := make(map[string]versionedNode)
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{
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fullPath := filepath.Join(this.rootPath(), path)
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nodes, err := ioutil.ReadDir(fullPath)
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if err != nil {
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return nil, err
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}
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for _, node := range nodes {
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name := node.Name()
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ownNodes[name] = versionedNode{
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info: node,
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path: filepath.Join(fullPath, name)}
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}
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}
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if this.parent == nil {
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return ownNodes, nil
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}
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baseNodes, err := this.parent.scanDir(path)
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if err != nil {
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return nil, err
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}
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for ownName, ownInfo := range ownNodes {
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baseNodes[ownName] = ownInfo
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}
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return baseNodes, nil
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}
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func (this *version) buildDir(path string, dir *versionedDir) error {
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nodes, err := this.scanDir(path)
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if err != nil {
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return err
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}
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for name, node := range nodes {
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if node.info.IsDir() {
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subDir := versionedDir{node: node, inode: this.allocInode()}
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subDirPath := filepath.Join(path, name)
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if err := this.buildDir(subDirPath, &subDir); err != nil {
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return err
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}
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dir.dirs[name] = subDir
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} else {
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dir.files[name] = versionedFile{node: node, inode: this.allocInode()}
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}
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}
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return nil
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}
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func (this *version) scanFs() error {
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rootNode, err := os.Stat(this.rootPath())
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if err != nil {
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return err
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}
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this.root = versionedDir{
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node: versionedNode{path: this.rootPath(), info: rootNode},
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inode: this.allocInode()}
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return this.buildDir(this.rootPath(), &this.root)
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}
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func (this *version) loadMetadata() error {
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path := this.metadataPath()
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if _, err := os.Stat(path); os.IsNotExist(err) {
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return nil
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}
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bytes, err := ioutil.ReadFile(this.metadataPath())
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if err != nil {
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return err
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}
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if err := json.Unmarshal(bytes, &this.meta); err != nil {
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return err
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}
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return nil
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}
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func (this *version) saveMetadata() error {
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js, err := json.Marshal(this.meta)
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if err != nil {
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return err
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}
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return ioutil.WriteFile(this.metadataPath(), js, 0644)
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}
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func (this *version) metadataPath() string {
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return filepath.Join(this.base, "meta.json")
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}
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func (this *version) rootPath() string {
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return filepath.Join(this.base, "root")
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}
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func (this *version) allocInode() uint64 {
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this.inodeCnt++
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return this.inodeCnt
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}
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func (this *version) Root() (fs.Node, error) {
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return this.root, nil
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}
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