syncthing/lib/db/set.go
Simon Frei 1f8e6c55f6
lib/db: Refactor to use global list by version (fixes #6372) (#6638)
Group the global list of files by version, instead of having one flat list for all devices. This removes lots of duplicate protocol.Vectors.

Co-authored-by: Jakob Borg <jakob@kastelo.net>
2020-05-30 09:50:23 +02:00

486 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 provides a set type to track local/remote files with newness
// checks. We must do a certain amount of normalization in here. We will get
// fed paths with either native or wire-format separators and encodings
// depending on who calls us. We transform paths to wire-format (NFC and
// slashes) on the way to the database, and transform to native format
// (varying separator and encoding) on the way back out.
package db
import (
"github.com/syncthing/syncthing/lib/db/backend"
"github.com/syncthing/syncthing/lib/fs"
"github.com/syncthing/syncthing/lib/osutil"
"github.com/syncthing/syncthing/lib/protocol"
"github.com/syncthing/syncthing/lib/sync"
)
type FileSet struct {
folder string
fs fs.Filesystem
db *Lowlevel
meta *metadataTracker
updateMutex sync.Mutex // protects database updates and the corresponding metadata changes
}
// The Iterator is called with either a protocol.FileInfo or a
// FileInfoTruncated (depending on the method) and returns true to
// continue iteration, false to stop.
type Iterator func(f protocol.FileIntf) bool
func NewFileSet(folder string, fs fs.Filesystem, db *Lowlevel) *FileSet {
return &FileSet{
folder: folder,
fs: fs,
db: db,
meta: db.loadMetadataTracker(folder),
updateMutex: sync.NewMutex(),
}
}
func (s *FileSet) Drop(device protocol.DeviceID) {
l.Debugf("%s Drop(%v)", s.folder, device)
s.updateMutex.Lock()
defer s.updateMutex.Unlock()
if err := s.db.dropDeviceFolder(device[:], []byte(s.folder), s.meta); backend.IsClosed(err) {
return
} else if err != nil {
panic(err)
}
if device == protocol.LocalDeviceID {
s.meta.resetCounts(device)
// We deliberately do not reset the sequence number here. Dropping
// all files for the local device ID only happens in testing - which
// expects the sequence to be retained, like an old Replace() of all
// files would do. However, if we ever did it "in production" we
// would anyway want to retain the sequence for delta indexes to be
// happy.
} else {
// Here, on the other hand, we want to make sure that any file
// announced from the remote is newer than our current sequence
// number.
s.meta.resetAll(device)
}
t, err := s.db.newReadWriteTransaction()
if backend.IsClosed(err) {
return
} else if err != nil {
panic(err)
}
defer t.close()
if err := s.meta.toDB(t, []byte(s.folder)); backend.IsClosed(err) {
return
} else if err != nil {
panic(err)
}
if err := t.Commit(); backend.IsClosed(err) {
return
} else if err != nil {
panic(err)
}
}
func (s *FileSet) Update(device protocol.DeviceID, fs []protocol.FileInfo) {
l.Debugf("%s Update(%v, [%d])", s.folder, device, len(fs))
// do not modify fs in place, it is still used in outer scope
fs = append([]protocol.FileInfo(nil), fs...)
// If one file info is present multiple times, only keep the last.
// Updating the same file multiple times is problematic, because the
// previous updates won't yet be represented in the db when we update it
// again. Additionally even if that problem was taken care of, it would
// be pointless because we remove the previously added file info again
// right away.
fs = normalizeFilenamesAndDropDuplicates(fs)
s.updateMutex.Lock()
defer s.updateMutex.Unlock()
if device == protocol.LocalDeviceID {
// For the local device we have a bunch of metadata to track.
if err := s.db.updateLocalFiles([]byte(s.folder), fs, s.meta); err != nil && !backend.IsClosed(err) {
panic(err)
}
return
}
// Easy case, just update the files and we're done.
if err := s.db.updateRemoteFiles([]byte(s.folder), device[:], fs, s.meta); err != nil && !backend.IsClosed(err) {
panic(err)
}
}
type Snapshot struct {
folder string
t readOnlyTransaction
meta *countsMap
}
func (s *FileSet) Snapshot() *Snapshot {
t, err := s.db.newReadOnlyTransaction()
if err != nil {
panic(err)
}
return &Snapshot{
folder: s.folder,
t: t,
meta: s.meta.Snapshot(),
}
}
func (s *Snapshot) Release() {
s.t.close()
}
func (s *Snapshot) WithNeed(device protocol.DeviceID, fn Iterator) {
l.Debugf("%s WithNeed(%v)", s.folder, device)
if err := s.t.withNeed([]byte(s.folder), device[:], false, nativeFileIterator(fn)); err != nil && !backend.IsClosed(err) {
panic(err)
}
}
func (s *Snapshot) WithNeedTruncated(device protocol.DeviceID, fn Iterator) {
l.Debugf("%s WithNeedTruncated(%v)", s.folder, device)
if err := s.t.withNeed([]byte(s.folder), device[:], true, nativeFileIterator(fn)); err != nil && !backend.IsClosed(err) {
panic(err)
}
}
func (s *Snapshot) WithHave(device protocol.DeviceID, fn Iterator) {
l.Debugf("%s WithHave(%v)", s.folder, device)
if err := s.t.withHave([]byte(s.folder), device[:], nil, false, nativeFileIterator(fn)); err != nil && !backend.IsClosed(err) {
panic(err)
}
}
func (s *Snapshot) WithHaveTruncated(device protocol.DeviceID, fn Iterator) {
l.Debugf("%s WithHaveTruncated(%v)", s.folder, device)
if err := s.t.withHave([]byte(s.folder), device[:], nil, true, nativeFileIterator(fn)); err != nil && !backend.IsClosed(err) {
panic(err)
}
}
func (s *Snapshot) WithHaveSequence(startSeq int64, fn Iterator) {
l.Debugf("%s WithHaveSequence(%v)", s.folder, startSeq)
if err := s.t.withHaveSequence([]byte(s.folder), startSeq, nativeFileIterator(fn)); err != nil && !backend.IsClosed(err) {
panic(err)
}
}
// Except for an item with a path equal to prefix, only children of prefix are iterated.
// E.g. for prefix "dir", "dir/file" is iterated, but "dir.file" is not.
func (s *Snapshot) WithPrefixedHaveTruncated(device protocol.DeviceID, prefix string, fn Iterator) {
l.Debugf(`%s WithPrefixedHaveTruncated(%v, "%v")`, s.folder, device, prefix)
if err := s.t.withHave([]byte(s.folder), device[:], []byte(osutil.NormalizedFilename(prefix)), true, nativeFileIterator(fn)); err != nil && !backend.IsClosed(err) {
panic(err)
}
}
func (s *Snapshot) WithGlobal(fn Iterator) {
l.Debugf("%s WithGlobal()", s.folder)
if err := s.t.withGlobal([]byte(s.folder), nil, false, nativeFileIterator(fn)); err != nil && !backend.IsClosed(err) {
panic(err)
}
}
func (s *Snapshot) WithGlobalTruncated(fn Iterator) {
l.Debugf("%s WithGlobalTruncated()", s.folder)
if err := s.t.withGlobal([]byte(s.folder), nil, true, nativeFileIterator(fn)); err != nil && !backend.IsClosed(err) {
panic(err)
}
}
// Except for an item with a path equal to prefix, only children of prefix are iterated.
// E.g. for prefix "dir", "dir/file" is iterated, but "dir.file" is not.
func (s *Snapshot) WithPrefixedGlobalTruncated(prefix string, fn Iterator) {
l.Debugf(`%s WithPrefixedGlobalTruncated("%v")`, s.folder, prefix)
if err := s.t.withGlobal([]byte(s.folder), []byte(osutil.NormalizedFilename(prefix)), true, nativeFileIterator(fn)); err != nil && !backend.IsClosed(err) {
panic(err)
}
}
func (s *Snapshot) Get(device protocol.DeviceID, file string) (protocol.FileInfo, bool) {
f, ok, err := s.t.getFile([]byte(s.folder), device[:], []byte(osutil.NormalizedFilename(file)))
if backend.IsClosed(err) {
return protocol.FileInfo{}, false
} else if err != nil {
panic(err)
}
f.Name = osutil.NativeFilename(f.Name)
return f, ok
}
func (s *Snapshot) GetGlobal(file string) (protocol.FileInfo, bool) {
_, fi, ok, err := s.t.getGlobal(nil, []byte(s.folder), []byte(osutil.NormalizedFilename(file)), false)
if backend.IsClosed(err) {
return protocol.FileInfo{}, false
} else if err != nil {
panic(err)
}
if !ok {
return protocol.FileInfo{}, false
}
f := fi.(protocol.FileInfo)
f.Name = osutil.NativeFilename(f.Name)
return f, true
}
func (s *Snapshot) GetGlobalTruncated(file string) (FileInfoTruncated, bool) {
_, fi, ok, err := s.t.getGlobal(nil, []byte(s.folder), []byte(osutil.NormalizedFilename(file)), true)
if backend.IsClosed(err) {
return FileInfoTruncated{}, false
} else if err != nil {
panic(err)
}
if !ok {
return FileInfoTruncated{}, false
}
f := fi.(FileInfoTruncated)
f.Name = osutil.NativeFilename(f.Name)
return f, true
}
func (s *Snapshot) Availability(file string) []protocol.DeviceID {
av, err := s.t.availability([]byte(s.folder), []byte(osutil.NormalizedFilename(file)))
if backend.IsClosed(err) {
return nil
} else if err != nil {
panic(err)
}
return av
}
func (s *Snapshot) Sequence(device protocol.DeviceID) int64 {
return s.meta.Counts(device, 0).Sequence
}
// RemoteSequence returns the change version for the given folder, as
// sent by remote peers. This is guaranteed to increment if the contents of
// the remote or global folder has changed.
func (s *Snapshot) RemoteSequence() int64 {
var ver int64
for _, device := range s.meta.devices() {
ver += s.Sequence(device)
}
return ver
}
func (s *Snapshot) LocalSize() Counts {
local := s.meta.Counts(protocol.LocalDeviceID, 0)
return local.Add(s.ReceiveOnlyChangedSize())
}
func (s *Snapshot) ReceiveOnlyChangedSize() Counts {
return s.meta.Counts(protocol.LocalDeviceID, protocol.FlagLocalReceiveOnly)
}
func (s *Snapshot) GlobalSize() Counts {
global := s.meta.Counts(protocol.GlobalDeviceID, 0)
recvOnlyChanged := s.meta.Counts(protocol.GlobalDeviceID, protocol.FlagLocalReceiveOnly)
return global.Add(recvOnlyChanged)
}
func (s *Snapshot) NeedSize(device protocol.DeviceID) Counts {
return s.meta.Counts(device, needFlag)
}
// LocalChangedFiles returns a paginated list of files that were changed locally.
func (s *Snapshot) LocalChangedFiles(page, perpage int) []FileInfoTruncated {
if s.ReceiveOnlyChangedSize().TotalItems() == 0 {
return nil
}
files := make([]FileInfoTruncated, 0, perpage)
skip := (page - 1) * perpage
get := perpage
s.WithHaveTruncated(protocol.LocalDeviceID, func(f protocol.FileIntf) bool {
if !f.IsReceiveOnlyChanged() {
return true
}
if skip > 0 {
skip--
return true
}
ft := f.(FileInfoTruncated)
files = append(files, ft)
get--
return get > 0
})
return files
}
// RemoteNeedFolderFiles returns paginated list of currently needed files in
// progress, queued, and to be queued on next puller iteration, as well as the
// total number of files currently needed.
func (s *Snapshot) RemoteNeedFolderFiles(device protocol.DeviceID, page, perpage int) []FileInfoTruncated {
files := make([]FileInfoTruncated, 0, perpage)
skip := (page - 1) * perpage
get := perpage
s.WithNeedTruncated(device, func(f protocol.FileIntf) bool {
if skip > 0 {
skip--
return true
}
files = append(files, f.(FileInfoTruncated))
get--
return get > 0
})
return files
}
func (s *Snapshot) WithBlocksHash(hash []byte, fn Iterator) {
l.Debugf(`%s WithBlocksHash("%x")`, s.folder, hash)
if err := s.t.withBlocksHash([]byte(s.folder), hash, nativeFileIterator(fn)); err != nil && !backend.IsClosed(err) {
panic(err)
}
}
func (s *FileSet) Sequence(device protocol.DeviceID) int64 {
return s.meta.Sequence(device)
}
func (s *FileSet) IndexID(device protocol.DeviceID) protocol.IndexID {
id, err := s.db.getIndexID(device[:], []byte(s.folder))
if backend.IsClosed(err) {
return 0
} else if err != nil {
panic(err)
}
if id == 0 && device == protocol.LocalDeviceID {
// No index ID set yet. We create one now.
id = protocol.NewIndexID()
err := s.db.setIndexID(device[:], []byte(s.folder), id)
if backend.IsClosed(err) {
return 0
} else if err != nil {
panic(err)
}
}
return id
}
func (s *FileSet) SetIndexID(device protocol.DeviceID, id protocol.IndexID) {
if device == protocol.LocalDeviceID {
panic("do not explicitly set index ID for local device")
}
if err := s.db.setIndexID(device[:], []byte(s.folder), id); err != nil && !backend.IsClosed(err) {
panic(err)
}
}
func (s *FileSet) MtimeFS() *fs.MtimeFS {
prefix, err := s.db.keyer.GenerateMtimesKey(nil, []byte(s.folder))
if backend.IsClosed(err) {
return nil
} else if err != nil {
panic(err)
}
kv := NewNamespacedKV(s.db, string(prefix))
return fs.NewMtimeFS(s.fs, kv)
}
func (s *FileSet) ListDevices() []protocol.DeviceID {
return s.meta.devices()
}
func (s *FileSet) RepairSequence() (int, error) {
s.updateAndGCMutexLock() // Ensures consistent locking order
defer s.updateMutex.Unlock()
defer s.db.gcMut.RUnlock()
return s.db.repairSequenceGCLocked(s.folder, s.meta)
}
func (s *FileSet) updateAndGCMutexLock() {
s.updateMutex.Lock()
s.db.gcMut.RLock()
}
// DropFolder clears out all information related to the given folder from the
// database.
func DropFolder(db *Lowlevel, folder string) {
droppers := []func([]byte) error{
db.dropFolder,
db.dropMtimes,
db.dropFolderMeta,
db.folderIdx.Delete,
}
for _, drop := range droppers {
if err := drop([]byte(folder)); backend.IsClosed(err) {
return
} else if err != nil {
panic(err)
}
}
}
// DropDeltaIndexIDs removes all delta index IDs from the database.
// This will cause a full index transmission on the next connection.
func DropDeltaIndexIDs(db *Lowlevel) {
dbi, err := db.NewPrefixIterator([]byte{KeyTypeIndexID})
if backend.IsClosed(err) {
return
} else if err != nil {
panic(err)
}
defer dbi.Release()
for dbi.Next() {
if err := db.Delete(dbi.Key()); err != nil && !backend.IsClosed(err) {
panic(err)
}
}
if err := dbi.Error(); err != nil && !backend.IsClosed(err) {
panic(err)
}
}
func normalizeFilenamesAndDropDuplicates(fs []protocol.FileInfo) []protocol.FileInfo {
positions := make(map[string]int, len(fs))
for i, f := range fs {
norm := osutil.NormalizedFilename(f.Name)
if pos, ok := positions[norm]; ok {
fs[pos] = protocol.FileInfo{}
}
positions[norm] = i
fs[i].Name = norm
}
for i := 0; i < len(fs); {
if fs[i].Name == "" {
fs = append(fs[:i], fs[i+1:]...)
continue
}
i++
}
return fs
}
func nativeFileIterator(fn Iterator) Iterator {
return func(fi protocol.FileIntf) bool {
switch f := fi.(type) {
case protocol.FileInfo:
f.Name = osutil.NativeFilename(f.Name)
return fn(f)
case FileInfoTruncated:
f.Name = osutil.NativeFilename(f.Name)
return fn(f)
default:
panic("unknown interface type")
}
}
}