syncthing/lib/versioner/simple.go
2019-02-02 11:45:17 +01:00

120 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 https://mozilla.org/MPL/2.0/.
package versioner
import (
"path/filepath"
"strconv"
"github.com/syncthing/syncthing/lib/fs"
"github.com/syncthing/syncthing/lib/osutil"
"github.com/syncthing/syncthing/lib/util"
)
func init() {
// Register the constructor for this type of versioner with the name "simple"
Factories["simple"] = NewSimple
}
type Simple struct {
keep int
fs fs.Filesystem
}
func NewSimple(folderID string, fs fs.Filesystem, params map[string]string) Versioner {
keep, err := strconv.Atoi(params["keep"])
if err != nil {
keep = 5 // A reasonable default
}
s := Simple{
keep: keep,
fs: fs,
}
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// returns nil, the named file does not exist any more (has been archived).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 {
info, err := v.fs.Lstat(filePath)
if fs.IsNotExist(err) {
l.Debugln("not archiving nonexistent file", filePath)
return nil
} else if err != nil {
return err
}
if info.IsSymlink() {
panic("bug: attempting to version a symlink")
}
versionsDir := ".stversions"
_, err = v.fs.Stat(versionsDir)
if err != nil {
if fs.IsNotExist(err) {
l.Debugln("creating versions dir .stversions")
_ = v.fs.Mkdir(versionsDir, 0755)
_ = v.fs.Hide(versionsDir)
} else {
return err
}
}
l.Debugln("archiving", filePath)
file := filepath.Base(filePath)
inFolderPath := filepath.Dir(filePath)
dir := filepath.Join(versionsDir, inFolderPath)
err = v.fs.MkdirAll(dir, 0755)
if err != nil && !fs.IsExist(err) {
return err
}
ver := TagFilename(file, info.ModTime().Format(TimeFormat))
dst := filepath.Join(dir, ver)
l.Debugln("moving to", dst)
err = osutil.Rename(v.fs, filePath, dst)
if err != nil {
return err
}
// Glob according to the new file~timestamp.ext pattern.
pattern := filepath.Join(dir, TagFilename(file, TimeGlob))
newVersions, err := v.fs.Glob(pattern)
if err != nil {
l.Warnln("globbing:", err, "for", pattern)
return nil
}
// Also according to the old file.ext~timestamp pattern.
pattern = filepath.Join(dir, file+"~"+TimeGlob)
oldVersions, err := v.fs.Glob(pattern)
if err != nil {
l.Warnln("globbing:", err, "for", pattern)
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 := util.UniqueStrings(append(oldVersions, newVersions...))
if len(versions) > v.keep {
for _, toRemove := range versions[:len(versions)-v.keep] {
l.Debugln("cleaning out", toRemove)
err = v.fs.Remove(toRemove)
if err != nil {
l.Warnln("removing old version:", err)
}
}
}
return nil
}