vfs/database.go
2015-06-24 12:42:36 +09:00

155 lines
3.1 KiB
Go

/*
* Copyright (c) 2015 Alex Yatskov <alex@foosoft.net>
* Author: Alex Yatskov <alex@foosoft.net>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package main
import (
"errors"
"fmt"
"io/ioutil"
"os"
"path"
"path/filepath"
"sort"
"time"
"bazil.org/fuse/fs"
)
//
// database
//
type database struct {
base string
vers verList
}
func newDatabase(path string) (*database, error) {
base, err := filepath.Abs(path)
if err != nil {
return nil, err
}
return &database{base, nil}, nil
}
func (db *database) load(index uint) error {
var err error
db.vers, err = db.loadVers(db.base)
if err != nil {
return err
}
if index > uint(len(db.vers)) {
return errors.New("invalid version index")
}
if index > 0 {
db.vers = db.vers[:index]
}
if lastVer := db.lastVer(); lastVer != nil {
return lastVer.resolve()
}
return nil
}
func (db *database) save() error {
lastVer := db.lastVer()
for _, ver := range db.vers {
if err := ver.finalize(ver == lastVer); err != nil {
return err
}
}
return nil
}
func (db *database) loadVers(base string) (verList, error) {
nodes, err := ioutil.ReadDir(base)
if err != nil {
return nil, err
}
var vers verList
for _, node := range nodes {
if !node.IsDir() {
continue
}
timestamp, err := parseVerName(node.Name())
if err != nil {
return nil, err
}
ver, err := newVer(path.Join(base, node.Name()), timestamp, db)
if err != nil {
return nil, err
}
vers = append(vers, ver)
}
sort.Sort(vers)
var pv *version
for _, ver := range vers {
ver.parent = pv
pv = ver
}
return vers, nil
}
func (db *database) lastVer() *version {
count := len(db.vers)
if count == 0 {
return nil
}
return db.vers[count-1]
}
func (db *database) createNewVer() error {
name := buildVerName(time.Now())
if err := os.MkdirAll(path.Join(db.base, name, "root"), 0755); err != nil {
return err
}
return nil
}
func (db *database) dump() {
for index, ver := range db.vers {
fmt.Printf("version: %d\ttime: %s\n", index+1, ver.timestamp.String())
}
}
// FS
func (db *database) Root() (fs.Node, error) {
return db.lastVer().root, nil
}