syncthing/internal/versioner/simple.go

144 lines
3.5 KiB
Go

// Copyright (C) 2014 The Syncthing Authors.
//
// This program is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation, either version 3 of the License, or (at your option)
// any later version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
// more details.
//
// You should have received a copy of the GNU General Public License along
// with this program. If not, see <http://www.gnu.org/licenses/>.
package versioner
import (
"os"
"path/filepath"
"sort"
"strconv"
"github.com/syncthing/syncthing/internal/osutil"
)
func init() {
// Register the constructor for this type of versioner with the name "simple"
Factories["simple"] = NewSimple
}
// The type holds our configuration
type Simple struct {
keep int
folderPath string
}
// The constructor function takes a map of parameters and creates the type.
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
}
// Move away the named file 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// nil, the named file does not exist any more (has been archived).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 := os.Stat(filePath)
if err != nil {
if os.IsNotExist(err) {
if debug {
l.Debugln("not archiving nonexistent file", filePath)
}
return nil
} else {
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)
}
os.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 = os.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 := filepath.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 := filepath.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 := append(oldVersions, newVersions...)
if len(versions) > v.keep {
sort.Strings(versions)
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
}