syncthing/lib/versioner/trashcan.go
2017-11-18 15:56:53 +00:00

164 lines
3.7 KiB
Go

// Copyright (C) 2015 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 (
"fmt"
"path/filepath"
"strconv"
"time"
"github.com/syncthing/syncthing/lib/fs"
"github.com/syncthing/syncthing/lib/osutil"
)
func init() {
// Register the constructor for this type of versioner
Factories["trashcan"] = NewTrashcan
}
type Trashcan struct {
fs fs.Filesystem
cleanoutDays int
stop chan struct{}
}
func NewTrashcan(folderID string, fs fs.Filesystem, params map[string]string) Versioner {
cleanoutDays, _ := strconv.Atoi(params["cleanoutDays"])
// On error we default to 0, "do not clean out the trash can"
s := &Trashcan{
fs: fs,
cleanoutDays: cleanoutDays,
stop: make(chan struct{}),
}
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// returns nil, the named file does not exist any more (has been archived).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 (t *Trashcan) Archive(filePath string) error {
info, err := t.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"
if _, err := t.fs.Stat(versionsDir); err != nil {
if !fs.IsNotExist(err) {
return err
}
l.Debugln("creating versions dir", versionsDir)
if err := t.fs.MkdirAll(versionsDir, 0777); err != nil {
return err
}
t.fs.Hide(versionsDir)
}
l.Debugln("archiving", filePath)
archivedPath := filepath.Join(versionsDir, filePath)
if err := t.fs.MkdirAll(filepath.Dir(archivedPath), 0777); err != nil && !fs.IsExist(err) {
return err
}
l.Debugln("moving to", archivedPath)
if err := osutil.Rename(t.fs, filePath, archivedPath); err != nil {
return err
}
// Set the mtime to the time the file was deleted. This is used by the
// cleanout routine. If this fails things won't work optimally but there's
// not much we can do about it so we ignore the error.
t.fs.Chtimes(archivedPath, time.Now(), time.Now())
return nil
}
func (t *Trashcan) Serve() {
l.Debugln(t, "starting")
defer l.Debugln(t, "stopping")
// Do the first cleanup one minute after startup.
timer := time.NewTimer(time.Minute)
defer timer.Stop()
for {
select {
case <-t.stop:
return
case <-timer.C:
if t.cleanoutDays > 0 {
if err := t.cleanoutArchive(); err != nil {
l.Infoln("Cleaning trashcan:", err)
}
}
// Cleanups once a day should be enough.
timer.Reset(24 * time.Hour)
}
}
}
func (t *Trashcan) Stop() {
close(t.stop)
}
func (t *Trashcan) String() string {
return fmt.Sprintf("trashcan@%p", t)
}
func (t *Trashcan) cleanoutArchive() error {
versionsDir := ".stversions"
if _, err := t.fs.Lstat(versionsDir); fs.IsNotExist(err) {
return nil
}
cutoff := time.Now().Add(time.Duration(-24*t.cleanoutDays) * time.Hour)
dirTracker := make(emptyDirTracker)
walkFn := func(path string, info fs.FileInfo, err error) error {
if err != nil {
return err
}
if info.IsDir() && !info.IsSymlink() {
dirTracker.addDir(path)
return nil
}
if info.ModTime().Before(cutoff) {
// The file is too old; remove it.
t.fs.Remove(path)
} else {
// Keep this file, and remember it so we don't unnecessarily try
// to remove this directory.
dirTracker.addFile(path)
}
return nil
}
if err := t.fs.Walk(versionsDir, walkFn); err != nil {
return err
}
dirTracker.deleteEmptyDirs(t.fs)
return nil
}