package files import ( "bytes" "runtime" "sort" "sync" "github.com/syncthing/syncthing/lamport" "github.com/syncthing/syncthing/protocol" "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 uint64 clockMut sync.Mutex ) func clock(v uint64) uint64 { clockMut.Lock() defer clockMut.Unlock() if v > clockTick { clockTick = v + 1 } else { clockTick++ } return clockTick } const ( keyTypeNode = iota keyTypeGlobal ) type fileVersion struct { version uint64 node []byte } type versionList struct { versions []fileVersion } 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) } /* keyTypeNode (1 byte) repository (64 bytes) node (32 bytes) name (variable size) | scanner.File keyTypeGlobal (1 byte) repository (64 bytes) name (variable size) | []fileVersion (sorted) */ func nodeKey(repo, node, file []byte) []byte { k := make([]byte, 1+64+32+len(file)) k[0] = keyTypeNode copy(k[1:], []byte(repo)) copy(k[1+64:], node[:]) copy(k[1+64+32:], []byte(file)) return k } func globalKey(repo, file []byte) []byte { k := make([]byte, 1+64+len(file)) k[0] = keyTypeGlobal copy(k[1:], []byte(repo)) copy(k[1+64:], []byte(file)) return k } func nodeKeyName(key []byte) []byte { return key[1+64+32:] } func nodeKeyRepo(key []byte) []byte { repo := key[1 : 1+64] izero := bytes.IndexByte(repo, 0) return repo[:izero] } func nodeKeyNode(key []byte) []byte { return key[1+64 : 1+64+32] } func globalKeyName(key []byte) []byte { return key[1+64:] } type deletionHandler func(db dbReader, batch dbWriter, repo, node, name []byte, dbi iterator.Iterator) uint64 type fileIterator func(f protocol.FileIntf) bool func ldbGenericReplace(db *leveldb.DB, repo, node []byte, fs []protocol.FileInfo, deleteFn deletionHandler) uint64 { defer runtime.GC() sort.Sort(fileList(fs)) // sort list on name, same as on disk start := nodeKey(repo, node, nil) // before all repo/node files limit := nodeKey(repo, node, []byte{0xff, 0xff, 0xff, 0xff}) // after all repo/node files batch := new(leveldb.Batch) snap, err := db.GetSnapshot() if err != nil { panic(err) } defer snap.Release() dbi := snap.NewIterator(&util.Range{Start: start, Limit: limit}, nil) defer dbi.Release() moreDb := dbi.Next() fsi := 0 var maxLocalVer uint64 for { var newName, oldName []byte moreFs := fsi < len(fs) if !moreDb && !moreFs { break } if !moreFs && deleteFn == nil { // We don't have any more updated files to process and deletion // has not been requested, so we can exit early break } if moreFs { newName = []byte(fs[fsi].Name) } if moreDb { oldName = nodeKeyName(dbi.Key()) } cmp := bytes.Compare(newName, oldName) if debug { l.Debugf("generic replace; repo=%q node=%v moreFs=%v moreDb=%v cmp=%d newName=%q oldName=%q", repo, protocol.NodeIDFromBytes(node), moreFs, moreDb, cmp, newName, oldName) } switch { case moreFs && (!moreDb || cmp == -1): // Disk is missing this file. Insert it. if lv := ldbInsert(batch, repo, node, newName, fs[fsi]); lv > maxLocalVer { maxLocalVer = lv } ldbUpdateGlobal(snap, batch, repo, node, newName, fs[fsi].Version) fsi++ case moreFs && moreDb && cmp == 0: // File exists on both sides - compare versions. var ef protocol.FileInfoTruncated ef.UnmarshalXDR(dbi.Value()) if fs[fsi].Version > ef.Version { if lv := ldbInsert(batch, repo, node, newName, fs[fsi]); lv > maxLocalVer { maxLocalVer = lv } ldbUpdateGlobal(snap, batch, repo, node, newName, fs[fsi].Version) } // Iterate both sides. fsi++ moreDb = dbi.Next() case moreDb && (!moreFs || cmp == 1): if deleteFn != nil { if lv := deleteFn(snap, batch, repo, node, oldName, dbi); lv > maxLocalVer { maxLocalVer = lv } } moreDb = dbi.Next() } } err = db.Write(batch, nil) if err != nil { panic(err) } return maxLocalVer } func ldbReplace(db *leveldb.DB, repo, node []byte, fs []protocol.FileInfo) uint64 { // TODO: Return the remaining maxLocalVer? return ldbGenericReplace(db, repo, node, fs, func(db dbReader, batch dbWriter, repo, node, name []byte, dbi iterator.Iterator) uint64 { // Disk has files that we are missing. Remove it. if debug { l.Debugf("delete; repo=%q node=%v name=%q", repo, protocol.NodeIDFromBytes(node), name) } ldbRemoveFromGlobal(db, batch, repo, node, name) batch.Delete(dbi.Key()) return 0 }) } func ldbReplaceWithDelete(db *leveldb.DB, repo, node []byte, fs []protocol.FileInfo) uint64 { return ldbGenericReplace(db, repo, node, fs, func(db dbReader, batch dbWriter, repo, node, name []byte, dbi iterator.Iterator) uint64 { var tf protocol.FileInfoTruncated err := tf.UnmarshalXDR(dbi.Value()) if err != nil { panic(err) } if !tf.IsDeleted() { if debug { l.Debugf("mark deleted; repo=%q node=%v name=%q", repo, protocol.NodeIDFromBytes(node), name) } ts := clock(tf.LocalVersion) f := protocol.FileInfo{ Name: tf.Name, Version: lamport.Default.Tick(tf.Version), LocalVersion: ts, Flags: tf.Flags | protocol.FlagDeleted, Modified: tf.Modified, } batch.Put(dbi.Key(), f.MarshalXDR()) ldbUpdateGlobal(db, batch, repo, node, nodeKeyName(dbi.Key()), f.Version) return ts } return 0 }) } func ldbUpdate(db *leveldb.DB, repo, node []byte, fs []protocol.FileInfo) uint64 { defer runtime.GC() batch := new(leveldb.Batch) snap, err := db.GetSnapshot() if err != nil { panic(err) } defer snap.Release() var maxLocalVer uint64 for _, f := range fs { name := []byte(f.Name) fk := nodeKey(repo, node, name) bs, err := snap.Get(fk, nil) if err == leveldb.ErrNotFound { if lv := ldbInsert(batch, repo, node, name, f); lv > maxLocalVer { maxLocalVer = lv } ldbUpdateGlobal(snap, batch, repo, node, name, f.Version) continue } var ef protocol.FileInfoTruncated err = ef.UnmarshalXDR(bs) if err != nil { panic(err) } if ef.Version != f.Version { if lv := ldbInsert(batch, repo, node, name, f); lv > maxLocalVer { maxLocalVer = lv } ldbUpdateGlobal(snap, batch, repo, node, name, f.Version) } } err = db.Write(batch, nil) if err != nil { panic(err) } return maxLocalVer } func ldbInsert(batch dbWriter, repo, node, name []byte, file protocol.FileInfo) uint64 { if debug { l.Debugf("insert; repo=%q node=%v %v", repo, protocol.NodeIDFromBytes(node), file) } if file.LocalVersion == 0 { file.LocalVersion = clock(0) } nk := nodeKey(repo, node, name) batch.Put(nk, file.MarshalXDR()) return file.LocalVersion } // ldbUpdateGlobal adds this node+version to the version list for the given // file. If the node 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, repo, node, file []byte, version uint64) bool { if debug { l.Debugf("update global; repo=%q node=%v file=%q version=%d", repo, protocol.NodeIDFromBytes(node), file, version) } gk := globalKey(repo, file) svl, err := db.Get(gk, nil) if err != nil && err != leveldb.ErrNotFound { panic(err) } var fl versionList nv := fileVersion{ node: node, version: version, } if svl != nil { err = fl.UnmarshalXDR(svl) if err != nil { panic(err) } for i := range fl.versions { if bytes.Compare(fl.versions[i].node, node) == 0 { if fl.versions[i].version == version { // No need to do anything return false } fl.versions = append(fl.versions[:i], fl.versions[i+1:]...) break } } } for i := range fl.versions { if fl.versions[i].version <= version { t := append(fl.versions, fileVersion{}) copy(t[i+1:], t[i:]) t[i] = nv fl.versions = t goto done } } fl.versions = append(fl.versions, nv) done: batch.Put(gk, fl.MarshalXDR()) return true } // ldbRemoveFromGlobal removes the node 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, repo, node, file []byte) { if debug { l.Debugf("remove from global; repo=%q node=%v file=%q", repo, protocol.NodeIDFromBytes(node), file) } gk := globalKey(repo, file) svl, err := db.Get(gk, nil) if err != nil { panic(err) } var fl versionList err = fl.UnmarshalXDR(svl) if err != nil { panic(err) } for i := range fl.versions { if bytes.Compare(fl.versions[i].node, node) == 0 { fl.versions = append(fl.versions[:i], fl.versions[i+1:]...) break } } if len(fl.versions) == 0 { batch.Delete(gk) } else { batch.Put(gk, fl.MarshalXDR()) } } func ldbWithHave(db *leveldb.DB, repo, node []byte, truncate bool, fn fileIterator) { start := nodeKey(repo, node, nil) // before all repo/node files limit := nodeKey(repo, node, []byte{0xff, 0xff, 0xff, 0xff}) // after all repo/node files snap, err := db.GetSnapshot() if err != nil { panic(err) } defer 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 ldbWithAllRepoTruncated(db *leveldb.DB, repo []byte, fn func(node []byte, f protocol.FileInfoTruncated) bool) { defer runtime.GC() start := nodeKey(repo, nil, nil) // before all repo/node files limit := nodeKey(repo, protocol.LocalNodeID[:], []byte{0xff, 0xff, 0xff, 0xff}) // after all repo/node files snap, err := db.GetSnapshot() if err != nil { panic(err) } defer snap.Release() dbi := snap.NewIterator(&util.Range{Start: start, Limit: limit}, nil) defer dbi.Release() for dbi.Next() { node := nodeKeyNode(dbi.Key()) var f protocol.FileInfoTruncated err := f.UnmarshalXDR(dbi.Value()) if err != nil { panic(err) } if cont := fn(node, f); !cont { return } } } func ldbGet(db *leveldb.DB, repo, node, file []byte) protocol.FileInfo { nk := nodeKey(repo, node, file) bs, err := db.Get(nk, nil) if err == leveldb.ErrNotFound { return protocol.FileInfo{} } if err != nil { panic(err) } var f protocol.FileInfo err = f.UnmarshalXDR(bs) if err != nil { panic(err) } return f } func ldbGetGlobal(db *leveldb.DB, repo, file []byte) protocol.FileInfo { k := globalKey(repo, file) snap, err := db.GetSnapshot() if err != nil { panic(err) } defer snap.Release() bs, err := snap.Get(k, nil) if err == leveldb.ErrNotFound { return protocol.FileInfo{} } 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 = nodeKey(repo, vl.versions[0].node, file) bs, err = snap.Get(k, nil) if err != nil { panic(err) } var f protocol.FileInfo err = f.UnmarshalXDR(bs) if err != nil { panic(err) } return f } func ldbWithGlobal(db *leveldb.DB, repo []byte, truncate bool, fn fileIterator) { defer runtime.GC() start := globalKey(repo, nil) limit := globalKey(repo, []byte{0xff, 0xff, 0xff, 0xff}) snap, err := db.GetSnapshot() if err != nil { panic(err) } defer snap.Release() dbi := snap.NewIterator(&util.Range{Start: start, Limit: limit}, nil) defer dbi.Release() 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?") } fk := nodeKey(repo, vl.versions[0].node, globalKeyName(dbi.Key())) bs, err := snap.Get(fk, nil) if err != nil { panic(err) } f, err := unmarshalTrunc(bs, truncate) if err != nil { panic(err) } if cont := fn(f); !cont { return } } } func ldbAvailability(db *leveldb.DB, repo, file []byte) []protocol.NodeID { k := globalKey(repo, 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 nodes []protocol.NodeID for _, v := range vl.versions { if v.version != vl.versions[0].version { break } n := protocol.NodeIDFromBytes(v.node) nodes = append(nodes, n) } return nodes } func ldbWithNeed(db *leveldb.DB, repo, node []byte, truncate bool, fn fileIterator) { defer runtime.GC() start := globalKey(repo, nil) limit := globalKey(repo, []byte{0xff, 0xff, 0xff, 0xff}) snap, err := db.GetSnapshot() if err != nil { panic(err) } defer snap.Release() dbi := snap.NewIterator(&util.Range{Start: start, Limit: limit}, nil) defer dbi.Release() 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 uint64 for _, v := range vl.versions { if bytes.Compare(v.node, node) == 0 { have = true haveVersion = v.version need = v.version < vl.versions[0].version break } } if need || !have { name := globalKeyName(dbi.Key()) fk := nodeKey(repo, vl.versions[0].node, name) bs, err := snap.Get(fk, nil) if err != nil { panic(err) } gf, err := unmarshalTrunc(bs, truncate) if err != nil { panic(err) } if gf.IsDeleted() && !have { // We don't need deleted files that we don't have continue } if debug { l.Debugf("need repo=%q node=%v name=%q need=%v have=%v haveV=%d globalV=%d", repo, protocol.NodeIDFromBytes(node), name, need, have, haveVersion, vl.versions[0].version) } if cont := fn(gf); !cont { return } } } } func unmarshalTrunc(bs []byte, truncate bool) (protocol.FileIntf, error) { if truncate { var tf protocol.FileInfoTruncated err := tf.UnmarshalXDR(bs) return tf, err } else { var tf protocol.FileInfo err := tf.UnmarshalXDR(bs) return tf, err } }