package ethdb import ( "strconv" "strings" "time" "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 GetTimer metrics.Timer // Timer for measuring the database get request counts and latencies PutTimer metrics.Timer // Timer for measuring the database put request counts and latencies DelTimer metrics.Timer // Timer for measuring the database delete request counts and latencies MissMeter metrics.Meter // Meter for measuring the missed database get requests ReadMeter metrics.Meter // Meter for measuring the database get request data usage WriteMeter metrics.Meter // Meter for measuring the database put request data usage CompTimeMeter metrics.Meter // Meter for measuring the total time spent in database compaction CompReadMeter metrics.Meter // Meter for measuring the data read during compaction CompWriteMeter metrics.Meter // Meter for measuring the data written during compaction } // 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, } go database.meter(3 * time.Second) return database, nil } // Put puts the given key / value to the queue func (self *LDBDatabase) Put(key []byte, value []byte) error { // Measure the database put latency, if requested if self.PutTimer != nil { defer self.PutTimer.UpdateSince(time.Now()) } // Generate the data to write to disk, update the meter and write dat := rle.Compress(value) 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) { // Measure the database get latency, if requested if self.GetTimer != nil { defer self.GetTimer.UpdateSince(time.Now()) } // Retrieve the key and increment the miss counter if not found dat, err := self.db.Get(key, nil) if err != nil { if self.MissMeter != nil { self.MissMeter.Mark(1) } return nil, err } // Otherwise update the actually retrieved amount of data 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 { // Measure the database delete latency, if requested if self.DelTimer != nil { defer self.DelTimer.UpdateSince(time.Now()) } // Execute the actual operation 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) } func (self *LDBDatabase) LDB() *leveldb.DB { return self.db } // meter periodically retrieves internal leveldb counters and reports them to // the metrics subsystem. // // This is how a stats table look like (currently): // Compactions // Level | Tables | Size(MB) | Time(sec) | Read(MB) | Write(MB) // -------+------------+---------------+---------------+---------------+--------------- // 0 | 0 | 0.00000 | 1.27969 | 0.00000 | 12.31098 // 1 | 85 | 109.27913 | 28.09293 | 213.92493 | 214.26294 // 2 | 523 | 1000.37159 | 7.26059 | 66.86342 | 66.77884 // 3 | 570 | 1113.18458 | 0.00000 | 0.00000 | 0.00000 func (self *LDBDatabase) meter(refresh time.Duration) { // Create the counters to store current and previous values counters := make([][]float64, 2) for i := 0; i < 2; i++ { counters[i] = make([]float64, 3) } // Iterate ad infinitum and collect the stats for i := 1; ; i++ { // Retrieve the database stats stats, err := self.db.GetProperty("leveldb.stats") if err != nil { glog.V(logger.Error).Infof("failed to read database stats: %v", err) return } // Find the compaction table, skip the header lines := strings.Split(stats, "\n") for len(lines) > 0 && strings.TrimSpace(lines[0]) != "Compactions" { lines = lines[1:] } if len(lines) <= 3 { glog.V(logger.Error).Infof("compaction table not found") return } lines = lines[3:] // Iterate over all the table rows, and accumulate the entries for j := 0; j < len(counters[i%2]); j++ { counters[i%2][j] = 0 } for _, line := range lines { parts := strings.Split(line, "|") if len(parts) != 6 { break } for idx, counter := range parts[3:] { if value, err := strconv.ParseFloat(strings.TrimSpace(counter), 64); err != nil { glog.V(logger.Error).Infof("compaction entry parsing failed: %v", err) return } else { counters[i%2][idx] += value } } } // Update all the requested meters if self.CompTimeMeter != nil { self.CompTimeMeter.Mark(int64((counters[i%2][0] - counters[(i-1)%2][0]) * 1000 * 1000 * 1000)) } if self.CompReadMeter != nil { self.CompReadMeter.Mark(int64((counters[i%2][1] - counters[(i-1)%2][1]) * 1024 * 1024)) } if self.CompWriteMeter != nil { self.CompWriteMeter.Mark(int64((counters[i%2][2] - counters[(i-1)%2][2]) * 1024 * 1024)) } // Sleep a bit, then repeat the stats collection time.Sleep(refresh) } }