vfs/database.go
2015-05-12 19:48:11 +09:00

111 lines
2.4 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 (
"io/ioutil"
"path/filepath"
)
type database struct {
base string
vers []*version
}
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 {
base, err := filepath.Abs(dir)
if err != nil {
return err
}
dirs, err := this.scan(base)
if err != nil {
return err
}
vers, err := this.versions(dirs)
if err != nil {
return err
}
this.base = base
this.vers = vers
return nil
}
func (this *database) save() error {
return nil
}
func (this *database) versions(dirs []string) ([]*version, error) {
var vers []*version
var parent *version
for _, dir := range dirs {
ver, err := newVersion(dir, parent)
if err != nil {
return nil, err
}
vers = append(vers, ver)
parent = 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) scan(dir string) ([]string, error) {
nodes, err := ioutil.ReadDir(dir)
if err != nil {
return nil, err
}
var dirs []string
for _, node := range nodes {
if node.IsDir() {
dirs = append(dirs, node.Name())
}
}
return dirs, nil
}