package storage import ( "fmt" "os" "path/filepath" "github.com/chrislusf/seaweedfs/weed/glog" "github.com/chrislusf/seaweedfs/weed/storage/needle" . "github.com/chrislusf/seaweedfs/weed/storage/types" "github.com/chrislusf/seaweedfs/weed/util" "github.com/syndtr/goleveldb/leveldb" ) type LevelDbNeedleMap struct { dbFileName string db *leveldb.DB baseNeedleMapper } // TODO avoid using btree to count deletions. func NewLevelDbNeedleMap(dbFileName string, indexFile *os.File) (m *LevelDbNeedleMap, err error) { m = &LevelDbNeedleMap{dbFileName: dbFileName} m.indexFile = indexFile if !isLevelDbFresh(dbFileName, indexFile) { glog.V(1).Infof("Start to Generate %s from %s", dbFileName, indexFile.Name()) generateLevelDbFile(dbFileName, indexFile) glog.V(1).Infof("Finished Generating %s from %s", dbFileName, indexFile.Name()) } glog.V(1).Infof("Opening %s...", dbFileName) if m.db, err = leveldb.OpenFile(dbFileName, nil); err != nil { return } glog.V(1).Infof("Loading %s...", indexFile.Name()) mm, indexLoadError := newNeedleMapMetricFromIndexFile(indexFile) if indexLoadError != nil { return nil, indexLoadError } m.mapMetric = *mm return } func isLevelDbFresh(dbFileName string, indexFile *os.File) bool { // normally we always write to index file first dbLogFile, err := os.Open(filepath.Join(dbFileName, "LOG")) if err != nil { return false } defer dbLogFile.Close() dbStat, dbStatErr := dbLogFile.Stat() indexStat, indexStatErr := indexFile.Stat() if dbStatErr != nil || indexStatErr != nil { glog.V(0).Infof("Can not stat file: %v and %v", dbStatErr, indexStatErr) return false } return dbStat.ModTime().After(indexStat.ModTime()) } func generateLevelDbFile(dbFileName string, indexFile *os.File) error { db, err := leveldb.OpenFile(dbFileName, nil) if err != nil { return err } defer db.Close() return WalkIndexFile(indexFile, func(key NeedleId, offset Offset, size uint32) error { if offset > 0 && size != TombstoneFileSize { levelDbWrite(db, key, offset, size) } else { levelDbDelete(db, key) } return nil }) } func (m *LevelDbNeedleMap) Get(key NeedleId) (element *needle.NeedleValue, ok bool) { bytes := make([]byte, NeedleIdSize) NeedleIdToBytes(bytes[0:NeedleIdSize], key) data, err := m.db.Get(bytes, nil) if err != nil || len(data) != OffsetSize+SizeSize { return nil, false } offset := BytesToOffset(data[0:OffsetSize]) size := util.BytesToUint32(data[OffsetSize : OffsetSize+SizeSize]) return &needle.NeedleValue{Key: NeedleId(key), Offset: offset, Size: size}, true } func (m *LevelDbNeedleMap) Put(key NeedleId, offset Offset, size uint32) error { var oldSize uint32 if oldNeedle, ok := m.Get(key); ok { oldSize = oldNeedle.Size } m.logPut(key, oldSize, size) // write to index file first if err := m.appendToIndexFile(key, offset, size); err != nil { return fmt.Errorf("cannot write to indexfile %s: %v", m.indexFile.Name(), err) } return levelDbWrite(m.db, key, offset, size) } func levelDbWrite(db *leveldb.DB, key NeedleId, offset Offset, size uint32) error { bytes := make([]byte, NeedleIdSize+OffsetSize+SizeSize) NeedleIdToBytes(bytes[0:NeedleIdSize], key) OffsetToBytes(bytes[NeedleIdSize:NeedleIdSize+OffsetSize], offset) util.Uint32toBytes(bytes[NeedleIdSize+OffsetSize:NeedleIdSize+OffsetSize+SizeSize], size) if err := db.Put(bytes[0:NeedleIdSize], bytes[NeedleIdSize:NeedleIdSize+OffsetSize+SizeSize], nil); err != nil { return fmt.Errorf("failed to write leveldb: %v", err) } return nil } func levelDbDelete(db *leveldb.DB, key NeedleId) error { bytes := make([]byte, NeedleIdSize) NeedleIdToBytes(bytes, key) return db.Delete(bytes, nil) } func (m *LevelDbNeedleMap) Delete(key NeedleId, offset Offset) error { if oldNeedle, ok := m.Get(key); ok { m.logDelete(oldNeedle.Size) } // write to index file first if err := m.appendToIndexFile(key, offset, TombstoneFileSize); err != nil { return err } return levelDbDelete(m.db, key) } func (m *LevelDbNeedleMap) Close() { m.indexFile.Close() m.db.Close() } func (m *LevelDbNeedleMap) Destroy() error { m.Close() os.Remove(m.indexFile.Name()) return os.RemoveAll(m.dbFileName) }