syncthing/lib/db/leveldb.go
2015-08-09 09:35:26 +02:00

1059 lines
24 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/.
//go:generate -command genxdr go run ../../Godeps/_workspace/src/github.com/calmh/xdr/cmd/genxdr/main.go
//go:generate genxdr -o leveldb_xdr.go leveldb.go
package db
import (
"bytes"
"fmt"
"runtime"
"sort"
"github.com/syncthing/protocol"
"github.com/syncthing/syncthing/lib/sync"
"github.com/syndtr/goleveldb/leveldb"
"github.com/syndtr/goleveldb/leveldb/iterator"
"github.com/syndtr/goleveldb/leveldb/opt"
"github.com/syndtr/goleveldb/leveldb/util"
)
var (
clockTick int64
clockMut = sync.NewMutex()
)
func clock(v int64) int64 {
clockMut.Lock()
defer clockMut.Unlock()
if v > clockTick {
clockTick = v + 1
} else {
clockTick++
}
return clockTick
}
const (
KeyTypeDevice = iota
KeyTypeGlobal
KeyTypeBlock
KeyTypeDeviceStatistic
KeyTypeFolderStatistic
KeyTypeVirtualMtime
)
type fileVersion struct {
version protocol.Vector
device []byte
}
type versionList struct {
versions []fileVersion
}
func (l versionList) String() string {
var b bytes.Buffer
var id protocol.DeviceID
b.WriteString("{")
for i, v := range l.versions {
if i > 0 {
b.WriteString(", ")
}
copy(id[:], v.device)
fmt.Fprintf(&b, "{%d, %v}", v.version, id)
}
b.WriteString("}")
return b.String()
}
type fileList []protocol.FileInfo
func (l fileList) Len() int {
return len(l)
}
func (l fileList) Swap(a, b int) {
l[a], l[b] = l[b], l[a]
}
func (l fileList) Less(a, b int) bool {
return l[a].Name < l[b].Name
}
type dbReader interface {
Get([]byte, *opt.ReadOptions) ([]byte, error)
}
type dbWriter interface {
Put([]byte, []byte)
Delete([]byte)
}
// Flush batches to disk when they contain this many records.
const batchFlushSize = 64
// deviceKey returns a byte slice encoding the following information:
// keyTypeDevice (1 byte)
// folder (64 bytes)
// device (32 bytes)
// name (variable size)
func deviceKey(folder, device, file []byte) []byte {
return deviceKeyInto(nil, folder, device, file)
}
func deviceKeyInto(k []byte, folder, device, file []byte) []byte {
reqLen := 1 + 64 + 32 + len(file)
if len(k) < reqLen {
k = make([]byte, reqLen)
}
k[0] = KeyTypeDevice
if len(folder) > 64 {
panic("folder name too long")
}
copy(k[1:], []byte(folder))
copy(k[1+64:], device[:])
copy(k[1+64+32:], []byte(file))
return k[:reqLen]
}
func deviceKeyName(key []byte) []byte {
return key[1+64+32:]
}
func deviceKeyFolder(key []byte) []byte {
folder := key[1 : 1+64]
izero := bytes.IndexByte(folder, 0)
if izero < 0 {
return folder
}
return folder[:izero]
}
func deviceKeyDevice(key []byte) []byte {
return key[1+64 : 1+64+32]
}
// globalKey returns a byte slice encoding the following information:
// keyTypeGlobal (1 byte)
// folder (64 bytes)
// name (variable size)
func globalKey(folder, file []byte) []byte {
k := make([]byte, 1+64+len(file))
k[0] = KeyTypeGlobal
if len(folder) > 64 {
panic("folder name too long")
}
copy(k[1:], []byte(folder))
copy(k[1+64:], []byte(file))
return k
}
func globalKeyName(key []byte) []byte {
return key[1+64:]
}
func globalKeyFolder(key []byte) []byte {
folder := key[1 : 1+64]
izero := bytes.IndexByte(folder, 0)
if izero < 0 {
return folder
}
return folder[:izero]
}
type deletionHandler func(db dbReader, batch dbWriter, folder, device, name []byte, dbi iterator.Iterator) int64
func ldbGenericReplace(db *leveldb.DB, folder, device []byte, fs []protocol.FileInfo, deleteFn deletionHandler) int64 {
runtime.GC()
sort.Sort(fileList(fs)) // sort list on name, same as in the database
start := deviceKey(folder, device, nil) // before all folder/device files
limit := deviceKey(folder, device, []byte{0xff, 0xff, 0xff, 0xff}) // after all folder/device files
batch := new(leveldb.Batch)
if debugDB {
l.Debugf("new batch %p", batch)
}
snap, err := db.GetSnapshot()
if err != nil {
panic(err)
}
if debugDB {
l.Debugf("created snapshot %p", snap)
}
defer func() {
if debugDB {
l.Debugf("close snapshot %p", snap)
}
snap.Release()
}()
dbi := snap.NewIterator(&util.Range{Start: start, Limit: limit}, nil)
defer dbi.Release()
moreDb := dbi.Next()
fsi := 0
var maxLocalVer int64
for {
var newName, oldName []byte
moreFs := fsi < len(fs)
if !moreDb && !moreFs {
break
}
if moreFs {
newName = []byte(fs[fsi].Name)
}
if moreDb {
oldName = deviceKeyName(dbi.Key())
}
cmp := bytes.Compare(newName, oldName)
if debugDB {
l.Debugf("generic replace; folder=%q device=%v moreFs=%v moreDb=%v cmp=%d newName=%q oldName=%q", folder, protocol.DeviceIDFromBytes(device), moreFs, moreDb, cmp, newName, oldName)
}
switch {
case moreFs && (!moreDb || cmp == -1):
if debugDB {
l.Debugln("generic replace; missing - insert")
}
// Database is missing this file. Insert it.
if lv := ldbInsert(batch, folder, device, fs[fsi]); lv > maxLocalVer {
maxLocalVer = lv
}
if fs[fsi].IsInvalid() {
ldbRemoveFromGlobal(snap, batch, folder, device, newName)
} else {
ldbUpdateGlobal(snap, batch, folder, device, fs[fsi])
}
fsi++
case moreFs && moreDb && cmp == 0:
// File exists on both sides - compare versions. We might get an
// update with the same version and different flags if a device has
// marked a file as invalid, so handle that too.
if debugDB {
l.Debugln("generic replace; exists - compare")
}
var ef FileInfoTruncated
ef.UnmarshalXDR(dbi.Value())
if !fs[fsi].Version.Equal(ef.Version) || fs[fsi].Flags != ef.Flags {
if debugDB {
l.Debugln("generic replace; differs - insert")
}
if lv := ldbInsert(batch, folder, device, fs[fsi]); lv > maxLocalVer {
maxLocalVer = lv
}
if fs[fsi].IsInvalid() {
ldbRemoveFromGlobal(snap, batch, folder, device, newName)
} else {
ldbUpdateGlobal(snap, batch, folder, device, fs[fsi])
}
} else if debugDB {
l.Debugln("generic replace; equal - ignore")
}
fsi++
moreDb = dbi.Next()
case moreDb && (!moreFs || cmp == 1):
if debugDB {
l.Debugln("generic replace; exists - remove")
}
if lv := deleteFn(snap, batch, folder, device, oldName, dbi); lv > maxLocalVer {
maxLocalVer = lv
}
moreDb = dbi.Next()
}
// Write out and reuse the batch every few records, to avoid the batch
// growing too large and thus allocating unnecessarily much memory.
if batch.Len() > batchFlushSize {
if debugDB {
l.Debugf("db.Write %p", batch)
}
err = db.Write(batch, nil)
if err != nil {
panic(err)
}
batch.Reset()
}
}
if debugDB {
l.Debugf("db.Write %p", batch)
}
err = db.Write(batch, nil)
if err != nil {
panic(err)
}
return maxLocalVer
}
func ldbReplace(db *leveldb.DB, folder, device []byte, fs []protocol.FileInfo) int64 {
// TODO: Return the remaining maxLocalVer?
return ldbGenericReplace(db, folder, device, fs, func(db dbReader, batch dbWriter, folder, device, name []byte, dbi iterator.Iterator) int64 {
// Database has a file that we are missing. Remove it.
if debugDB {
l.Debugf("delete; folder=%q device=%v name=%q", folder, protocol.DeviceIDFromBytes(device), name)
}
ldbRemoveFromGlobal(db, batch, folder, device, name)
if debugDB {
l.Debugf("batch.Delete %p %x", batch, dbi.Key())
}
batch.Delete(dbi.Key())
return 0
})
}
func ldbUpdate(db *leveldb.DB, folder, device []byte, fs []protocol.FileInfo) int64 {
runtime.GC()
batch := new(leveldb.Batch)
if debugDB {
l.Debugf("new batch %p", batch)
}
snap, err := db.GetSnapshot()
if err != nil {
panic(err)
}
if debugDB {
l.Debugf("created snapshot %p", snap)
}
defer func() {
if debugDB {
l.Debugf("close snapshot %p", snap)
}
snap.Release()
}()
var maxLocalVer int64
var fk []byte
for _, f := range fs {
name := []byte(f.Name)
fk = deviceKeyInto(fk[:cap(fk)], folder, device, name)
if debugDB {
l.Debugf("snap.Get %p %x", snap, fk)
}
bs, err := snap.Get(fk, nil)
if err == leveldb.ErrNotFound {
if lv := ldbInsert(batch, folder, device, f); lv > maxLocalVer {
maxLocalVer = lv
}
if f.IsInvalid() {
ldbRemoveFromGlobal(snap, batch, folder, device, name)
} else {
ldbUpdateGlobal(snap, batch, folder, device, f)
}
continue
}
var ef FileInfoTruncated
err = ef.UnmarshalXDR(bs)
if err != nil {
panic(err)
}
// Flags might change without the version being bumped when we set the
// invalid flag on an existing file.
if !ef.Version.Equal(f.Version) || ef.Flags != f.Flags {
if lv := ldbInsert(batch, folder, device, f); lv > maxLocalVer {
maxLocalVer = lv
}
if f.IsInvalid() {
ldbRemoveFromGlobal(snap, batch, folder, device, name)
} else {
ldbUpdateGlobal(snap, batch, folder, device, f)
}
}
// Write out and reuse the batch every few records, to avoid the batch
// growing too large and thus allocating unnecessarily much memory.
if batch.Len() > batchFlushSize {
if debugDB {
l.Debugf("db.Write %p", batch)
}
err = db.Write(batch, nil)
if err != nil {
panic(err)
}
batch.Reset()
}
}
if debugDB {
l.Debugf("db.Write %p", batch)
}
err = db.Write(batch, nil)
if err != nil {
panic(err)
}
return maxLocalVer
}
func ldbInsert(batch dbWriter, folder, device []byte, file protocol.FileInfo) int64 {
if debugDB {
l.Debugf("insert; folder=%q device=%v %v", folder, protocol.DeviceIDFromBytes(device), file)
}
if file.LocalVersion == 0 {
file.LocalVersion = clock(0)
}
name := []byte(file.Name)
nk := deviceKey(folder, device, name)
if debugDB {
l.Debugf("batch.Put %p %x", batch, nk)
}
batch.Put(nk, file.MustMarshalXDR())
return file.LocalVersion
}
// ldbUpdateGlobal adds this device+version to the version list for the given
// file. If the device is already present in the list, the version is updated.
// If the file does not have an entry in the global list, it is created.
func ldbUpdateGlobal(db dbReader, batch dbWriter, folder, device []byte, file protocol.FileInfo) bool {
if debugDB {
l.Debugf("update global; folder=%q device=%v file=%q version=%d", folder, protocol.DeviceIDFromBytes(device), file.Name, file.Version)
}
name := []byte(file.Name)
gk := globalKey(folder, name)
svl, err := db.Get(gk, nil)
if err != nil && err != leveldb.ErrNotFound {
panic(err)
}
var fl versionList
// Remove the device from the current version list
if svl != nil {
err = fl.UnmarshalXDR(svl)
if err != nil {
panic(err)
}
for i := range fl.versions {
if bytes.Compare(fl.versions[i].device, device) == 0 {
if fl.versions[i].version.Equal(file.Version) {
// No need to do anything
return false
}
fl.versions = append(fl.versions[:i], fl.versions[i+1:]...)
break
}
}
}
nv := fileVersion{
device: device,
version: file.Version,
}
// Find a position in the list to insert this file. The file at the front
// of the list is the newer, the "global".
for i := range fl.versions {
switch fl.versions[i].version.Compare(file.Version) {
case protocol.Equal, protocol.Lesser:
// The version at this point in the list is equal to or lesser
// ("older") than us. We insert ourselves in front of it.
fl.versions = insertVersion(fl.versions, i, nv)
goto done
case protocol.ConcurrentLesser, protocol.ConcurrentGreater:
// The version at this point is in conflict with us. We must pull
// the actual file metadata to determine who wins. If we win, we
// insert ourselves in front of the loser here. (The "Lesser" and
// "Greater" in the condition above is just based on the device
// IDs in the version vector, which is not the only thing we use
// to determine the winner.)
of, ok := ldbGet(db, folder, fl.versions[i].device, name)
if !ok {
panic("file referenced in version list does not exist")
}
if file.WinsConflict(of) {
fl.versions = insertVersion(fl.versions, i, nv)
goto done
}
}
}
// We didn't find a position for an insert above, so append to the end.
fl.versions = append(fl.versions, nv)
done:
if debugDB {
l.Debugf("batch.Put %p %x", batch, gk)
l.Debugf("new global after update: %v", fl)
}
batch.Put(gk, fl.MustMarshalXDR())
return true
}
func insertVersion(vl []fileVersion, i int, v fileVersion) []fileVersion {
t := append(vl, fileVersion{})
copy(t[i+1:], t[i:])
t[i] = v
return t
}
// ldbRemoveFromGlobal removes the device from the global version list for the
// given file. If the version list is empty after this, the file entry is
// removed entirely.
func ldbRemoveFromGlobal(db dbReader, batch dbWriter, folder, device, file []byte) {
if debugDB {
l.Debugf("remove from global; folder=%q device=%v file=%q", folder, protocol.DeviceIDFromBytes(device), file)
}
gk := globalKey(folder, file)
svl, err := db.Get(gk, nil)
if err != nil {
// We might be called to "remove" a global version that doesn't exist
// if the first update for the file is already marked invalid.
return
}
var fl versionList
err = fl.UnmarshalXDR(svl)
if err != nil {
panic(err)
}
for i := range fl.versions {
if bytes.Compare(fl.versions[i].device, device) == 0 {
fl.versions = append(fl.versions[:i], fl.versions[i+1:]...)
break
}
}
if len(fl.versions) == 0 {
if debugDB {
l.Debugf("batch.Delete %p %x", batch, gk)
}
batch.Delete(gk)
} else {
if debugDB {
l.Debugf("batch.Put %p %x", batch, gk)
l.Debugf("new global after remove: %v", fl)
}
batch.Put(gk, fl.MustMarshalXDR())
}
}
func ldbWithHave(db *leveldb.DB, folder, device []byte, truncate bool, fn Iterator) {
start := deviceKey(folder, device, nil) // before all folder/device files
limit := deviceKey(folder, device, []byte{0xff, 0xff, 0xff, 0xff}) // after all folder/device files
snap, err := db.GetSnapshot()
if err != nil {
panic(err)
}
if debugDB {
l.Debugf("created snapshot %p", snap)
}
defer func() {
if debugDB {
l.Debugf("close snapshot %p", snap)
}
snap.Release()
}()
dbi := snap.NewIterator(&util.Range{Start: start, Limit: limit}, nil)
defer dbi.Release()
for dbi.Next() {
f, err := unmarshalTrunc(dbi.Value(), truncate)
if err != nil {
panic(err)
}
if cont := fn(f); !cont {
return
}
}
}
func ldbWithAllFolderTruncated(db *leveldb.DB, folder []byte, fn func(device []byte, f FileInfoTruncated) bool) {
runtime.GC()
start := deviceKey(folder, nil, nil) // before all folder/device files
limit := deviceKey(folder, protocol.LocalDeviceID[:], []byte{0xff, 0xff, 0xff, 0xff}) // after all folder/device files
snap, err := db.GetSnapshot()
if err != nil {
panic(err)
}
if debugDB {
l.Debugf("created snapshot %p", snap)
}
defer func() {
if debugDB {
l.Debugf("close snapshot %p", snap)
}
snap.Release()
}()
dbi := snap.NewIterator(&util.Range{Start: start, Limit: limit}, nil)
defer dbi.Release()
for dbi.Next() {
device := deviceKeyDevice(dbi.Key())
var f FileInfoTruncated
err := f.UnmarshalXDR(dbi.Value())
if err != nil {
panic(err)
}
switch f.Name {
case "", ".", "..", "/": // A few obviously invalid filenames
l.Infof("Dropping invalid filename %q from database", f.Name)
batch := new(leveldb.Batch)
ldbRemoveFromGlobal(db, batch, folder, device, nil)
batch.Delete(dbi.Key())
db.Write(batch, nil)
continue
}
if cont := fn(device, f); !cont {
return
}
}
}
func ldbGet(db dbReader, folder, device, file []byte) (protocol.FileInfo, bool) {
nk := deviceKey(folder, device, file)
bs, err := db.Get(nk, nil)
if err == leveldb.ErrNotFound {
return protocol.FileInfo{}, false
}
if err != nil {
panic(err)
}
var f protocol.FileInfo
err = f.UnmarshalXDR(bs)
if err != nil {
panic(err)
}
return f, true
}
func ldbGetGlobal(db *leveldb.DB, folder, file []byte, truncate bool) (FileIntf, bool) {
k := globalKey(folder, file)
snap, err := db.GetSnapshot()
if err != nil {
panic(err)
}
if debugDB {
l.Debugf("created snapshot %p", snap)
}
defer func() {
if debugDB {
l.Debugf("close snapshot %p", snap)
}
snap.Release()
}()
if debugDB {
l.Debugf("snap.Get %p %x", snap, k)
}
bs, err := snap.Get(k, nil)
if err == leveldb.ErrNotFound {
return nil, false
}
if err != nil {
panic(err)
}
var vl versionList
err = vl.UnmarshalXDR(bs)
if err != nil {
panic(err)
}
if len(vl.versions) == 0 {
l.Debugln(k)
panic("no versions?")
}
k = deviceKey(folder, vl.versions[0].device, file)
if debugDB {
l.Debugf("snap.Get %p %x", snap, k)
}
bs, err = snap.Get(k, nil)
if err != nil {
panic(err)
}
fi, err := unmarshalTrunc(bs, truncate)
if err != nil {
panic(err)
}
return fi, true
}
func ldbWithGlobal(db *leveldb.DB, folder, prefix []byte, truncate bool, fn Iterator) {
runtime.GC()
snap, err := db.GetSnapshot()
if err != nil {
panic(err)
}
if debugDB {
l.Debugf("created snapshot %p", snap)
}
defer func() {
if debugDB {
l.Debugf("close snapshot %p", snap)
}
snap.Release()
}()
dbi := snap.NewIterator(util.BytesPrefix(globalKey(folder, prefix)), nil)
defer dbi.Release()
var fk []byte
for dbi.Next() {
var vl versionList
err := vl.UnmarshalXDR(dbi.Value())
if err != nil {
panic(err)
}
if len(vl.versions) == 0 {
l.Debugln(dbi.Key())
panic("no versions?")
}
name := globalKeyName(dbi.Key())
fk = deviceKeyInto(fk[:cap(fk)], folder, vl.versions[0].device, name)
if debugDB {
l.Debugf("snap.Get %p %x", snap, fk)
}
bs, err := snap.Get(fk, nil)
if err != nil {
l.Debugf("folder: %q (%x)", folder, folder)
l.Debugf("key: %q (%x)", dbi.Key(), dbi.Key())
l.Debugf("vl: %v", vl)
l.Debugf("vl.versions[0].device: %x", vl.versions[0].device)
l.Debugf("name: %q (%x)", name, name)
l.Debugf("fk: %q", fk)
l.Debugf("fk: %x %x %x", fk[1:1+64], fk[1+64:1+64+32], fk[1+64+32:])
panic(err)
}
f, err := unmarshalTrunc(bs, truncate)
if err != nil {
panic(err)
}
if cont := fn(f); !cont {
return
}
}
}
func ldbAvailability(db *leveldb.DB, folder, file []byte) []protocol.DeviceID {
k := globalKey(folder, file)
bs, err := db.Get(k, nil)
if err == leveldb.ErrNotFound {
return nil
}
if err != nil {
panic(err)
}
var vl versionList
err = vl.UnmarshalXDR(bs)
if err != nil {
panic(err)
}
var devices []protocol.DeviceID
for _, v := range vl.versions {
if !v.version.Equal(vl.versions[0].version) {
break
}
n := protocol.DeviceIDFromBytes(v.device)
devices = append(devices, n)
}
return devices
}
func ldbWithNeed(db *leveldb.DB, folder, device []byte, truncate bool, fn Iterator) {
runtime.GC()
start := globalKey(folder, nil)
limit := globalKey(folder, []byte{0xff, 0xff, 0xff, 0xff})
snap, err := db.GetSnapshot()
if err != nil {
panic(err)
}
if debugDB {
l.Debugf("created snapshot %p", snap)
}
defer func() {
if debugDB {
l.Debugf("close snapshot %p", snap)
}
snap.Release()
}()
dbi := snap.NewIterator(&util.Range{Start: start, Limit: limit}, nil)
defer dbi.Release()
var fk []byte
nextFile:
for dbi.Next() {
var vl versionList
err := vl.UnmarshalXDR(dbi.Value())
if err != nil {
panic(err)
}
if len(vl.versions) == 0 {
l.Debugln(dbi.Key())
panic("no versions?")
}
have := false // If we have the file, any version
need := false // If we have a lower version of the file
var haveVersion protocol.Vector
for _, v := range vl.versions {
if bytes.Compare(v.device, device) == 0 {
have = true
haveVersion = v.version
// XXX: This marks Concurrent (i.e. conflicting) changes as
// needs. Maybe we should do that, but it needs special
// handling in the puller.
need = !v.version.GreaterEqual(vl.versions[0].version)
break
}
}
if need || !have {
name := globalKeyName(dbi.Key())
needVersion := vl.versions[0].version
nextVersion:
for i := range vl.versions {
if !vl.versions[i].version.Equal(needVersion) {
// We haven't found a valid copy of the file with the needed version.
continue nextFile
}
fk = deviceKeyInto(fk[:cap(fk)], folder, vl.versions[i].device, name)
if debugDB {
l.Debugf("snap.Get %p %x", snap, fk)
}
bs, err := snap.Get(fk, nil)
if err != nil {
var id protocol.DeviceID
copy(id[:], device)
l.Debugf("device: %v", id)
l.Debugf("need: %v, have: %v", need, have)
l.Debugf("key: %q (%x)", dbi.Key(), dbi.Key())
l.Debugf("vl: %v", vl)
l.Debugf("i: %v", i)
l.Debugf("fk: %q (%x)", fk, fk)
l.Debugf("name: %q (%x)", name, name)
panic(err)
}
gf, err := unmarshalTrunc(bs, truncate)
if err != nil {
panic(err)
}
if gf.IsInvalid() {
// The file is marked invalid for whatever reason, don't use it.
continue nextVersion
}
if gf.IsDeleted() && !have {
// We don't need deleted files that we don't have
continue nextFile
}
if debugDB {
l.Debugf("need folder=%q device=%v name=%q need=%v have=%v haveV=%d globalV=%d", folder, protocol.DeviceIDFromBytes(device), name, need, have, haveVersion, vl.versions[0].version)
}
if cont := fn(gf); !cont {
return
}
// This file is handled, no need to look further in the version list
continue nextFile
}
}
}
}
func ldbListFolders(db *leveldb.DB) []string {
runtime.GC()
snap, err := db.GetSnapshot()
if err != nil {
panic(err)
}
if debugDB {
l.Debugf("created snapshot %p", snap)
}
defer func() {
if debugDB {
l.Debugf("close snapshot %p", snap)
}
snap.Release()
}()
dbi := snap.NewIterator(util.BytesPrefix([]byte{KeyTypeGlobal}), nil)
defer dbi.Release()
folderExists := make(map[string]bool)
for dbi.Next() {
folder := string(globalKeyFolder(dbi.Key()))
if !folderExists[folder] {
folderExists[folder] = true
}
}
folders := make([]string, 0, len(folderExists))
for k := range folderExists {
folders = append(folders, k)
}
sort.Strings(folders)
return folders
}
func ldbDropFolder(db *leveldb.DB, folder []byte) {
runtime.GC()
snap, err := db.GetSnapshot()
if err != nil {
panic(err)
}
if debugDB {
l.Debugf("created snapshot %p", snap)
}
defer func() {
if debugDB {
l.Debugf("close snapshot %p", snap)
}
snap.Release()
}()
// Remove all items related to the given folder from the device->file bucket
dbi := snap.NewIterator(util.BytesPrefix([]byte{KeyTypeDevice}), nil)
for dbi.Next() {
itemFolder := deviceKeyFolder(dbi.Key())
if bytes.Compare(folder, itemFolder) == 0 {
db.Delete(dbi.Key(), nil)
}
}
dbi.Release()
// Remove all items related to the given folder from the global bucket
dbi = snap.NewIterator(util.BytesPrefix([]byte{KeyTypeGlobal}), nil)
for dbi.Next() {
itemFolder := globalKeyFolder(dbi.Key())
if bytes.Compare(folder, itemFolder) == 0 {
db.Delete(dbi.Key(), nil)
}
}
dbi.Release()
}
func unmarshalTrunc(bs []byte, truncate bool) (FileIntf, error) {
if truncate {
var tf FileInfoTruncated
err := tf.UnmarshalXDR(bs)
return tf, err
}
var tf protocol.FileInfo
err := tf.UnmarshalXDR(bs)
return tf, err
}
func ldbCheckGlobals(db *leveldb.DB, folder []byte) {
defer runtime.GC()
snap, err := db.GetSnapshot()
if err != nil {
panic(err)
}
if debugDB {
l.Debugf("created snapshot %p", snap)
}
defer func() {
if debugDB {
l.Debugf("close snapshot %p", snap)
}
snap.Release()
}()
start := globalKey(folder, nil)
limit := globalKey(folder, []byte{0xff, 0xff, 0xff, 0xff})
dbi := snap.NewIterator(&util.Range{Start: start, Limit: limit}, nil)
defer dbi.Release()
batch := new(leveldb.Batch)
if debugDB {
l.Debugf("new batch %p", batch)
}
var fk []byte
for dbi.Next() {
gk := dbi.Key()
var vl versionList
err := vl.UnmarshalXDR(dbi.Value())
if err != nil {
panic(err)
}
// Check the global version list for consistency. An issue in previous
// versions of goleveldb could result in reordered writes so that
// there are global entries pointing to no longer existing files. Here
// we find those and clear them out.
name := globalKeyName(gk)
var newVL versionList
for _, version := range vl.versions {
fk = deviceKeyInto(fk[:cap(fk)], folder, version.device, name)
if debugDB {
l.Debugf("snap.Get %p %x", snap, fk)
}
_, err := snap.Get(fk, nil)
if err == leveldb.ErrNotFound {
continue
}
if err != nil {
panic(err)
}
newVL.versions = append(newVL.versions, version)
}
if len(newVL.versions) != len(vl.versions) {
l.Infof("db repair: rewriting global version list for %x %x", gk[1:1+64], gk[1+64:])
batch.Put(dbi.Key(), newVL.MustMarshalXDR())
}
}
if debugDB {
l.Infoln("db check completed for %q", folder)
}
db.Write(batch, nil)
}