vfs/database.go
2015-06-17 16:41:43 +09:00

133 lines
2.8 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 (
"bazil.org/fuse/fs"
"io/ioutil"
"path"
"path/filepath"
"sort"
)
//
// database
//
type database struct {
base string
vers versionList
}
func newDatabase(dir string) (*database, error) {
db := &database{base: dir}
if err := db.load(dir); err != nil {
return nil, err
}
return db, nil
}
func (this *database) load(dir string) error {
var err error
this.base, err = filepath.Abs(dir)
if err != nil {
return err
}
if err := buildNewVersion(this.base); err != nil {
return err
}
this.vers, err = this.buildVersions(this.base)
if err != nil {
return err
}
if lastVer := this.lastVersion(); lastVer != nil {
return lastVer.resolve()
}
return nil
}
func (this *database) save() error {
for _, ver := range this.vers {
if err := ver.finalize(); err != nil {
return err
}
}
return nil
}
func (this *database) buildVersions(base string) (versionList, error) {
nodes, err := ioutil.ReadDir(base)
if err != nil {
return nil, err
}
var vers versionList
for _, node := range nodes {
if !node.IsDir() {
continue
}
timestamp, err := parseVerName(node.Name())
if err != nil {
return nil, err
}
ver, err := newVersion(path.Join(base, node.Name()), timestamp, this)
if err != nil {
return nil, err
}
vers = append(vers, ver)
}
sort.Sort(vers)
var parVer *version
for _, ver := range vers {
ver.parent = parVer
parVer = ver
}
return vers, nil
}
func (this *database) lastVersion() *version {
count := len(this.vers)
if count == 0 {
return nil
}
return this.vers[count-1]
}
func (this *database) Root() (fs.Node, error) {
return this.lastVersion().root, nil
}