syncthing/lib/db/instance.go
2019-01-19 20:21:58 +01:00

551 lines
14 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 db
import (
"bytes"
"fmt"
"github.com/syncthing/syncthing/lib/protocol"
"github.com/syndtr/goleveldb/leveldb"
"github.com/syndtr/goleveldb/leveldb/iterator"
"github.com/syndtr/goleveldb/leveldb/util"
)
type deletionHandler func(t readWriteTransaction, folder, device, name []byte, dbi iterator.Iterator)
type instance struct {
*Lowlevel
keyer keyer
}
func newInstance(ll *Lowlevel) *instance {
return &instance{
Lowlevel: ll,
keyer: newDefaultKeyer(ll.folderIdx, ll.deviceIdx),
}
}
func (db *instance) updateFiles(folder, device []byte, fs []protocol.FileInfo, meta *metadataTracker) {
t := db.newReadWriteTransaction()
defer t.close()
var fk []byte
var gk []byte
for _, f := range fs {
name := []byte(f.Name)
fk = db.keyer.GenerateDeviceFileKey(fk, folder, device, name)
ef, ok := t.getFileTrunc(fk, true)
if ok && unchanged(f, ef) {
continue
}
devID := protocol.DeviceIDFromBytes(device)
if ok {
meta.removeFile(devID, ef)
}
meta.addFile(devID, f)
t.insertFile(fk, folder, device, f)
gk = db.keyer.GenerateGlobalVersionKey(gk, folder, name)
t.updateGlobal(gk, folder, device, f, meta)
// Write out and reuse the batch every few records, to avoid the batch
// growing too large and thus allocating unnecessarily much memory.
t.checkFlush()
}
}
func (db *instance) addSequences(folder []byte, fs []protocol.FileInfo) {
t := db.newReadWriteTransaction()
defer t.close()
var sk []byte
var dk []byte
for _, f := range fs {
sk = db.keyer.GenerateSequenceKey(sk, folder, f.Sequence)
dk = db.keyer.GenerateDeviceFileKey(dk, folder, protocol.LocalDeviceID[:], []byte(f.Name))
t.Put(sk, dk)
l.Debugf("adding sequence; folder=%q sequence=%v %v", folder, f.Sequence, f.Name)
t.checkFlush()
}
}
func (db *instance) removeSequences(folder []byte, fs []protocol.FileInfo) {
t := db.newReadWriteTransaction()
defer t.close()
var sk []byte
for _, f := range fs {
t.Delete(db.keyer.GenerateSequenceKey(sk, folder, f.Sequence))
l.Debugf("removing sequence; folder=%q sequence=%v %v", folder, f.Sequence, f.Name)
t.checkFlush()
}
}
func (db *instance) withHave(folder, device, prefix []byte, truncate bool, fn Iterator) {
t := db.newReadOnlyTransaction()
defer t.close()
if len(prefix) > 0 {
unslashedPrefix := prefix
if bytes.HasSuffix(prefix, []byte{'/'}) {
unslashedPrefix = unslashedPrefix[:len(unslashedPrefix)-1]
} else {
prefix = append(prefix, '/')
}
if f, ok := t.getFileTrunc(db.keyer.GenerateDeviceFileKey(nil, folder, device, unslashedPrefix), true); ok && !fn(f) {
return
}
}
dbi := t.NewIterator(util.BytesPrefix(db.keyer.GenerateDeviceFileKey(nil, folder, device, prefix)), nil)
defer dbi.Release()
for dbi.Next() {
name := db.keyer.NameFromDeviceFileKey(dbi.Key())
if len(prefix) > 0 && !bytes.HasPrefix(name, prefix) {
return
}
f, err := unmarshalTrunc(dbi.Value(), truncate)
if err != nil {
l.Debugln("unmarshal error:", err)
continue
}
if !fn(f) {
return
}
}
}
func (db *instance) withHaveSequence(folder []byte, startSeq int64, fn Iterator) {
t := db.newReadOnlyTransaction()
defer t.close()
dbi := t.NewIterator(&util.Range{Start: db.keyer.GenerateSequenceKey(nil, folder, startSeq), Limit: db.keyer.GenerateSequenceKey(nil, folder, maxInt64)}, nil)
defer dbi.Release()
for dbi.Next() {
f, ok := t.getFileByKey(dbi.Value())
if !ok {
l.Debugln("missing file for sequence number", db.keyer.SequenceFromSequenceKey(dbi.Key()))
continue
}
if shouldDebug() {
if seq := db.keyer.SequenceFromSequenceKey(dbi.Key()); f.Sequence != seq {
panic(fmt.Sprintf("sequence index corruption (folder %v, file %v): sequence %d != expected %d", string(folder), f.Name, f.Sequence, seq))
}
}
if !fn(f) {
return
}
}
}
func (db *instance) withAllFolderTruncated(folder []byte, fn func(device []byte, f FileInfoTruncated) bool) {
t := db.newReadWriteTransaction()
defer t.close()
dbi := t.NewIterator(util.BytesPrefix(db.keyer.GenerateDeviceFileKey(nil, folder, nil, nil).WithoutNameAndDevice()), nil)
defer dbi.Release()
var gk []byte
for dbi.Next() {
device, ok := db.keyer.DeviceFromDeviceFileKey(dbi.Key())
if !ok {
// Not having the device in the index is bad. Clear it.
t.Delete(dbi.Key())
t.checkFlush()
continue
}
var f FileInfoTruncated
// The iterator function may keep a reference to the unmarshalled
// struct, which in turn references the buffer it was unmarshalled
// from. dbi.Value() just returns an internal slice that it reuses, so
// we need to copy it.
err := f.Unmarshal(append([]byte{}, dbi.Value()...))
if err != nil {
l.Debugln("unmarshal error:", err)
continue
}
switch f.Name {
case "", ".", "..", "/": // A few obviously invalid filenames
l.Infof("Dropping invalid filename %q from database", f.Name)
name := []byte(f.Name)
gk = db.keyer.GenerateGlobalVersionKey(gk, folder, name)
t.removeFromGlobal(gk, folder, device, name, nil)
t.Delete(dbi.Key())
t.checkFlush()
continue
}
if !fn(device, f) {
return
}
}
}
func (db *instance) getFileDirty(folder, device, file []byte) (protocol.FileInfo, bool) {
t := db.newReadOnlyTransaction()
defer t.close()
return t.getFile(folder, device, file)
}
func (db *instance) getGlobalDirty(folder, file []byte, truncate bool) (FileIntf, bool) {
t := db.newReadOnlyTransaction()
defer t.close()
_, _, f, ok := t.getGlobalInto(nil, nil, folder, file, truncate)
return f, ok
}
func (db *instance) withGlobal(folder, prefix []byte, truncate bool, fn Iterator) {
t := db.newReadOnlyTransaction()
defer t.close()
if len(prefix) > 0 {
unslashedPrefix := prefix
if bytes.HasSuffix(prefix, []byte{'/'}) {
unslashedPrefix = unslashedPrefix[:len(unslashedPrefix)-1]
} else {
prefix = append(prefix, '/')
}
if _, _, f, ok := t.getGlobalInto(nil, nil, folder, unslashedPrefix, truncate); ok && !fn(f) {
return
}
}
dbi := t.NewIterator(util.BytesPrefix(db.keyer.GenerateGlobalVersionKey(nil, folder, prefix)), nil)
defer dbi.Release()
var fk []byte
for dbi.Next() {
name := db.keyer.NameFromGlobalVersionKey(dbi.Key())
if len(prefix) > 0 && !bytes.HasPrefix(name, prefix) {
return
}
vl, ok := unmarshalVersionList(dbi.Value())
if !ok {
continue
}
fk = db.keyer.GenerateDeviceFileKey(fk, folder, vl.Versions[0].Device, name)
f, ok := t.getFileTrunc(fk, truncate)
if !ok {
continue
}
if !fn(f) {
return
}
}
}
func (db *instance) availability(folder, file []byte) []protocol.DeviceID {
k := db.keyer.GenerateGlobalVersionKey(nil, folder, file)
bs, err := db.Get(k, nil)
if err == leveldb.ErrNotFound {
return nil
}
if err != nil {
l.Debugln("surprise error:", err)
return nil
}
vl, ok := unmarshalVersionList(bs)
if !ok {
return nil
}
var devices []protocol.DeviceID
for _, v := range vl.Versions {
if !v.Version.Equal(vl.Versions[0].Version) {
break
}
if v.Invalid {
continue
}
n := protocol.DeviceIDFromBytes(v.Device)
devices = append(devices, n)
}
return devices
}
func (db *instance) withNeed(folder, device []byte, truncate bool, fn Iterator) {
if bytes.Equal(device, protocol.LocalDeviceID[:]) {
db.withNeedLocal(folder, truncate, fn)
return
}
t := db.newReadOnlyTransaction()
defer t.close()
dbi := t.NewIterator(util.BytesPrefix(db.keyer.GenerateGlobalVersionKey(nil, folder, nil).WithoutName()), nil)
defer dbi.Release()
var fk []byte
for dbi.Next() {
vl, ok := unmarshalVersionList(dbi.Value())
if !ok {
continue
}
haveFV, have := vl.Get(device)
// XXX: This marks Concurrent (i.e. conflicting) changes as
// needs. Maybe we should do that, but it needs special
// handling in the puller.
if have && haveFV.Version.GreaterEqual(vl.Versions[0].Version) {
continue
}
name := db.keyer.NameFromGlobalVersionKey(dbi.Key())
needVersion := vl.Versions[0].Version
needDevice := protocol.DeviceIDFromBytes(vl.Versions[0].Device)
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.
break
}
if vl.Versions[i].Invalid {
// The file is marked invalid, don't use it.
continue
}
fk = db.keyer.GenerateDeviceFileKey(fk, folder, vl.Versions[i].Device, name)
bs, err := t.Get(fk, nil)
if err != nil {
l.Debugln("surprise error:", err)
continue
}
gf, err := unmarshalTrunc(bs, truncate)
if err != nil {
l.Debugln("unmarshal error:", err)
continue
}
if gf.IsDeleted() && !have {
// We don't need deleted files that we don't have
break
}
l.Debugf("need folder=%q device=%v name=%q have=%v invalid=%v haveV=%v globalV=%v globalDev=%v", folder, protocol.DeviceIDFromBytes(device), name, have, haveFV.Invalid, haveFV.Version, needVersion, needDevice)
if !fn(gf) {
return
}
// This file is handled, no need to look further in the version list
break
}
}
}
func (db *instance) withNeedLocal(folder []byte, truncate bool, fn Iterator) {
t := db.newReadOnlyTransaction()
defer t.close()
dbi := t.NewIterator(util.BytesPrefix(db.keyer.GenerateNeedFileKey(nil, folder, nil).WithoutName()), nil)
defer dbi.Release()
var dk []byte
var gk []byte
var f FileIntf
var ok bool
for dbi.Next() {
gk, dk, f, ok = t.getGlobalInto(gk, dk, folder, db.keyer.NameFromGlobalVersionKey(dbi.Key()), truncate)
if !ok {
continue
}
if !fn(f) {
return
}
}
}
func (db *instance) dropFolder(folder []byte) {
t := db.newReadWriteTransaction()
defer t.close()
for _, key := range [][]byte{
// Remove all items related to the given folder from the device->file bucket
db.keyer.GenerateDeviceFileKey(nil, folder, nil, nil).WithoutNameAndDevice(),
// Remove all sequences related to the folder
db.keyer.GenerateSequenceKey(nil, []byte(folder), 0).WithoutSequence(),
// Remove all items related to the given folder from the global bucket
db.keyer.GenerateGlobalVersionKey(nil, folder, nil).WithoutName(),
// Remove all needs related to the folder
db.keyer.GenerateNeedFileKey(nil, folder, nil).WithoutName(),
} {
t.deleteKeyPrefix(key)
}
}
func (db *instance) dropDeviceFolder(device, folder []byte, meta *metadataTracker) {
t := db.newReadWriteTransaction()
defer t.close()
dbi := t.NewIterator(util.BytesPrefix(db.keyer.GenerateDeviceFileKey(nil, folder, device, nil)), nil)
defer dbi.Release()
var gk []byte
for dbi.Next() {
key := dbi.Key()
name := db.keyer.NameFromDeviceFileKey(key)
gk = db.keyer.GenerateGlobalVersionKey(gk, folder, name)
t.removeFromGlobal(gk, folder, device, name, meta)
t.Delete(key)
t.checkFlush()
}
}
func (db *instance) checkGlobals(folder []byte, meta *metadataTracker) {
t := db.newReadWriteTransaction()
defer t.close()
dbi := t.NewIterator(util.BytesPrefix(db.keyer.GenerateGlobalVersionKey(nil, folder, nil).WithoutName()), nil)
defer dbi.Release()
var fk []byte
for dbi.Next() {
vl, ok := unmarshalVersionList(dbi.Value())
if !ok {
continue
}
// 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 := db.keyer.NameFromGlobalVersionKey(dbi.Key())
var newVL VersionList
for i, version := range vl.Versions {
fk = db.keyer.GenerateDeviceFileKey(fk, folder, version.Device, name)
_, err := t.Get(fk, nil)
if err == leveldb.ErrNotFound {
continue
}
if err != nil {
l.Debugln("surprise error:", err)
return
}
newVL.Versions = append(newVL.Versions, version)
if i == 0 {
if fi, ok := t.getFileByKey(fk); ok {
meta.addFile(protocol.GlobalDeviceID, fi)
}
}
}
if len(newVL.Versions) != len(vl.Versions) {
t.Put(dbi.Key(), mustMarshal(&newVL))
t.checkFlush()
}
}
l.Debugf("db check completed for %q", folder)
}
func (db *instance) getIndexID(device, folder []byte) protocol.IndexID {
key := db.keyer.GenerateIndexIDKey(nil, device, folder)
cur, err := db.Get(key, nil)
if err != nil {
return 0
}
var id protocol.IndexID
if err := id.Unmarshal(cur); err != nil {
return 0
}
return id
}
func (db *instance) setIndexID(device, folder []byte, id protocol.IndexID) {
key := db.keyer.GenerateIndexIDKey(nil, device, folder)
bs, _ := id.Marshal() // marshalling can't fail
if err := db.Put(key, bs, nil); err != nil {
panic("storing index ID: " + err.Error())
}
}
func (db *instance) dropMtimes(folder []byte) {
db.dropPrefix(db.keyer.GenerateMtimesKey(nil, folder))
}
func (db *instance) dropFolderMeta(folder []byte) {
db.dropPrefix(db.keyer.GenerateFolderMetaKey(nil, folder))
}
func (db *instance) dropPrefix(prefix []byte) {
t := db.newReadWriteTransaction()
defer t.close()
dbi := t.NewIterator(util.BytesPrefix(prefix), nil)
defer dbi.Release()
for dbi.Next() {
t.Delete(dbi.Key())
}
}
func unmarshalTrunc(bs []byte, truncate bool) (FileIntf, error) {
if truncate {
var tf FileInfoTruncated
err := tf.Unmarshal(bs)
return tf, err
}
var tf protocol.FileInfo
err := tf.Unmarshal(bs)
return tf, err
}
func unmarshalVersionList(data []byte) (VersionList, bool) {
var vl VersionList
if err := vl.Unmarshal(data); err != nil {
l.Debugln("unmarshal error:", err)
return VersionList{}, false
}
if len(vl.Versions) == 0 {
l.Debugln("empty version list")
return VersionList{}, false
}
return vl, true
}
type errorSuggestion struct {
inner error
suggestion string
}
func (e errorSuggestion) Error() string {
return fmt.Sprintf("%s (%s)", e.inner.Error(), e.suggestion)
}
// unchanged checks if two files are the same and thus don't need to be updated.
// Local flags or the invalid bit might change without the version
// being bumped. The IsInvalid() method handles both.
func unchanged(nf, ef FileIntf) bool {
return ef.FileVersion().Equal(nf.FileVersion()) && ef.IsInvalid() == nf.IsInvalid()
}