syncthing/lib/db/leveldb_convert.go

115 lines
2.6 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 http://mozilla.org/MPL/2.0/.
package db
import (
"bytes"
"github.com/syndtr/goleveldb/leveldb"
)
// convertKeyFormat converts from the v0.12 to the v0.13 database format, to
// avoid having to do rescan. The change is in the key format for folder
// labels, so we basically just iterate over the database rewriting keys as
// necessary.
func convertKeyFormat(from, to *leveldb.DB) error {
l.Infoln("Converting database key format")
blocks, files, globals, unchanged := 0, 0, 0, 0
dbi := newDBInstance(to)
i := from.NewIterator(nil, nil)
for i.Next() {
key := i.Key()
switch key[0] {
case KeyTypeBlock:
folder, file := oldFromBlockKey(key)
folderIdx := dbi.folderIdx.ID([]byte(folder))
hash := key[1+64:]
newKey := blockKeyInto(nil, hash, folderIdx, file)
if err := to.Put(newKey, i.Value(), nil); err != nil {
return err
}
blocks++
case KeyTypeDevice:
newKey := dbi.deviceKey(oldDeviceKeyFolder(key), oldDeviceKeyDevice(key), oldDeviceKeyName(key))
if err := to.Put(newKey, i.Value(), nil); err != nil {
return err
}
files++
case KeyTypeGlobal:
newKey := dbi.globalKey(oldGlobalKeyFolder(key), oldGlobalKeyName(key))
if err := to.Put(newKey, i.Value(), nil); err != nil {
return err
}
globals++
case KeyTypeVirtualMtime:
// Cannot be converted, we drop it instead :(
default:
if err := to.Put(key, i.Value(), nil); err != nil {
return err
}
unchanged++
}
}
l.Infof("Converted %d blocks, %d files, %d globals (%d unchanged).", blocks, files, globals, unchanged)
return nil
}
func oldDeviceKeyFolder(key []byte) []byte {
folder := key[1 : 1+64]
izero := bytes.IndexByte(folder, 0)
if izero < 0 {
return folder
}
return folder[:izero]
}
func oldDeviceKeyDevice(key []byte) []byte {
return key[1+64 : 1+64+32]
}
func oldDeviceKeyName(key []byte) []byte {
return key[1+64+32:]
}
func oldGlobalKeyName(key []byte) []byte {
return key[1+64:]
}
func oldGlobalKeyFolder(key []byte) []byte {
folder := key[1 : 1+64]
izero := bytes.IndexByte(folder, 0)
if izero < 0 {
return folder
}
return folder[:izero]
}
func oldFromBlockKey(data []byte) (string, string) {
if len(data) < 1+64+32+1 {
panic("Incorrect key length")
}
if data[0] != KeyTypeBlock {
panic("Incorrect key type")
}
file := string(data[1+64+32:])
slice := data[1 : 1+64]
izero := bytes.IndexByte(slice, 0)
if izero > -1 {
return string(slice[:izero]), file
}
return string(slice), file
}