package ethdb import ( "github.com/ethereum/go-ethereum/compression/rle" "github.com/ethereum/go-ethereum/logger" "github.com/ethereum/go-ethereum/logger/glog" "github.com/rcrowley/go-metrics" "github.com/syndtr/goleveldb/leveldb" "github.com/syndtr/goleveldb/leveldb/errors" "github.com/syndtr/goleveldb/leveldb/iterator" "github.com/syndtr/goleveldb/leveldb/opt" ) var OpenFileLimit = 64 type LDBDatabase struct { fn string // filename for reporting db *leveldb.DB // LevelDB instance GetMeter metrics.Meter // Meter for measuring the database get request counts PutMeter metrics.Meter // Meter for measuring the database put request counts DelMeter metrics.Meter // Meter for measuring the database delete request counts ReadMeter metrics.Meter // Meter for measuring the database get request data usage WriteMeter metrics.Meter // Meter for measuring the database put request data usage } // NewLDBDatabase returns a LevelDB wrapped object. LDBDatabase does not persist data by // it self but requires a background poller which syncs every X. `Flush` should be called // when data needs to be stored and written to disk. func NewLDBDatabase(file string) (*LDBDatabase, error) { // Open the db db, err := leveldb.OpenFile(file, &opt.Options{OpenFilesCacheCapacity: OpenFileLimit}) // check for curruption and attempt to recover if _, iscorrupted := err.(*errors.ErrCorrupted); iscorrupted { db, err = leveldb.RecoverFile(file, nil) } // (re) check for errors and abort if opening of the db failed if err != nil { return nil, err } database := &LDBDatabase{ fn: file, db: db, } return database, nil } // Put puts the given key / value to the queue func (self *LDBDatabase) Put(key []byte, value []byte) error { dat := rle.Compress(value) if self.PutMeter != nil { self.PutMeter.Mark(1) } if self.WriteMeter != nil { self.WriteMeter.Mark(int64(len(dat))) } return self.db.Put(key, dat, nil) } // Get returns the given key if it's present. func (self *LDBDatabase) Get(key []byte) ([]byte, error) { dat, err := self.db.Get(key, nil) if err != nil { return nil, err } if self.GetMeter != nil { self.GetMeter.Mark(1) } if self.ReadMeter != nil { self.ReadMeter.Mark(int64(len(dat))) } return rle.Decompress(dat) } // Delete deletes the key from the queue and database func (self *LDBDatabase) Delete(key []byte) error { if self.DelMeter != nil { self.DelMeter.Mark(1) } return self.db.Delete(key, nil) } func (self *LDBDatabase) NewIterator() iterator.Iterator { return self.db.NewIterator(nil, nil) } // Flush flushes out the queue to leveldb func (self *LDBDatabase) Flush() error { return nil } func (self *LDBDatabase) Close() { if err := self.Flush(); err != nil { glog.V(logger.Error).Infof("error: flush '%s': %v\n", self.fn, err) } self.db.Close() glog.V(logger.Error).Infoln("flushed and closed db:", self.fn) }