syncthing/lib/versioner/simple.go
2015-08-09 09:35:26 +02:00

129 lines
2.9 KiB
Go

// Copyright (C) 2014 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at http://mozilla.org/MPL/2.0/.
package versioner
import (
"os"
"path/filepath"
"strconv"
"github.com/syncthing/syncthing/lib/osutil"
)
func init() {
// Register the constructor for this type of versioner with the name "simple"
Factories["simple"] = NewSimple
}
type Simple struct {
keep int
folderPath string
}
func NewSimple(folderID, folderPath string, params map[string]string) Versioner {
keep, err := strconv.Atoi(params["keep"])
if err != nil {
keep = 5 // A reasonable default
}
s := Simple{
keep: keep,
folderPath: folderPath,
}
if debug {
l.Debugf("instantiated %#v", s)
}
return s
}
// Archive moves the named file away to a version archive. If this function
// returns nil, the named file does not exist any more (has been archived).
func (v Simple) Archive(filePath string) error {
fileInfo, err := osutil.Lstat(filePath)
if os.IsNotExist(err) {
if debug {
l.Debugln("not archiving nonexistent file", filePath)
}
return nil
} else if err != nil {
return err
}
versionsDir := filepath.Join(v.folderPath, ".stversions")
_, err = os.Stat(versionsDir)
if err != nil {
if os.IsNotExist(err) {
if debug {
l.Debugln("creating versions dir", versionsDir)
}
osutil.MkdirAll(versionsDir, 0755)
osutil.HideFile(versionsDir)
} else {
return err
}
}
if debug {
l.Debugln("archiving", filePath)
}
file := filepath.Base(filePath)
inFolderPath, err := filepath.Rel(v.folderPath, filepath.Dir(filePath))
if err != nil {
return err
}
dir := filepath.Join(versionsDir, inFolderPath)
err = osutil.MkdirAll(dir, 0755)
if err != nil && !os.IsExist(err) {
return err
}
ver := taggedFilename(file, fileInfo.ModTime().Format(TimeFormat))
dst := filepath.Join(dir, ver)
if debug {
l.Debugln("moving to", dst)
}
err = osutil.Rename(filePath, dst)
if err != nil {
return err
}
// Glob according to the new file~timestamp.ext pattern.
newVersions, err := osutil.Glob(filepath.Join(dir, taggedFilename(file, TimeGlob)))
if err != nil {
l.Warnln("globbing:", err)
return nil
}
// Also according to the old file.ext~timestamp pattern.
oldVersions, err := osutil.Glob(filepath.Join(dir, file+"~"+TimeGlob))
if err != nil {
l.Warnln("globbing:", err)
return nil
}
// Use all the found filenames. "~" sorts after "." so all old pattern
// files will be deleted before any new, which is as it should be.
versions := uniqueSortedStrings(append(oldVersions, newVersions...))
if len(versions) > v.keep {
for _, toRemove := range versions[:len(versions)-v.keep] {
if debug {
l.Debugln("cleaning out", toRemove)
}
err = os.Remove(toRemove)
if err != nil {
l.Warnln("removing old version:", err)
}
}
}
return nil
}