diff --git a/swarm/shed/db.go b/swarm/shed/db.go index d4e5d1b23..6f6b16450 100644 --- a/swarm/shed/db.go +++ b/swarm/shed/db.go @@ -23,7 +23,6 @@ package shed import ( - "errors" "fmt" "strconv" "strings" @@ -56,7 +55,7 @@ type DB struct { diskReadMeter metrics.Meter // Meter for measuring the effective amount of data read diskWriteMeter metrics.Meter // Meter for measuring the effective amount of data written - quitChan chan chan error // Quit channel to stop the metrics collection before closing the database + quit chan struct{} // Quit channel to stop the metrics collection before closing the database } // NewDB constructs a new DB and validates the schema @@ -91,7 +90,7 @@ func NewDB(path string, metricsPrefix string) (db *DB, err error) { db.configure(metricsPrefix) // Create a quit channel for the periodic metrics collector and run it - db.quitChan = make(chan chan error) + db.quit = make(chan struct{}) go db.meter(10 * time.Second) @@ -155,7 +154,7 @@ func (db *DB) WriteBatch(batch *leveldb.Batch) (err error) { // Close closes LevelDB database. func (db *DB) Close() (err error) { - close(db.quitChan) + close(db.quit) return db.ldb.Close() } @@ -186,18 +185,12 @@ func (db *DB) meter(refresh time.Duration) { lastWritePaused time.Time ) - var ( - errc chan error - merr error - ) - // Iterate ad infinitum and collect the stats - for i := 1; errc == nil && merr == nil; i++ { + for i := 1; true; i++ { // Retrieve the database stats stats, err := db.ldb.GetProperty("leveldb.stats") if err != nil { log.Error("Failed to read database stats", "err", err) - merr = err continue } // Find the compaction table, skip the header @@ -207,7 +200,6 @@ func (db *DB) meter(refresh time.Duration) { } if len(lines) <= 3 { log.Error("Compaction table not found") - merr = errors.New("compaction table not found") continue } lines = lines[3:] @@ -225,7 +217,6 @@ func (db *DB) meter(refresh time.Duration) { value, err := strconv.ParseFloat(strings.TrimSpace(counter), 64) if err != nil { log.Error("Compaction entry parsing failed", "err", err) - merr = err continue } compactions[i%2][idx] += value @@ -246,7 +237,6 @@ func (db *DB) meter(refresh time.Duration) { writedelay, err := db.ldb.GetProperty("leveldb.writedelay") if err != nil { log.Error("Failed to read database write delay statistic", "err", err) - merr = err continue } var ( @@ -257,13 +247,11 @@ func (db *DB) meter(refresh time.Duration) { ) if n, err := fmt.Sscanf(writedelay, "DelayN:%d Delay:%s Paused:%t", &delayN, &delayDuration, &paused); n != 3 || err != nil { log.Error("Write delay statistic not found") - merr = err continue } duration, err = time.ParseDuration(delayDuration) if err != nil { log.Error("Failed to parse delay duration", "err", err) - merr = err continue } if db.writeDelayNMeter != nil { @@ -285,24 +273,20 @@ func (db *DB) meter(refresh time.Duration) { ioStats, err := db.ldb.GetProperty("leveldb.iostats") if err != nil { log.Error("Failed to read database iostats", "err", err) - merr = err continue } var nRead, nWrite float64 parts := strings.Split(ioStats, " ") if len(parts) < 2 { log.Error("Bad syntax of ioStats", "ioStats", ioStats) - merr = fmt.Errorf("bad syntax of ioStats %s", ioStats) continue } if n, err := fmt.Sscanf(parts[0], "Read(MB):%f", &nRead); n != 1 || err != nil { log.Error("Bad syntax of read entry", "entry", parts[0]) - merr = err continue } if n, err := fmt.Sscanf(parts[1], "Write(MB):%f", &nWrite); n != 1 || err != nil { log.Error("Bad syntax of write entry", "entry", parts[1]) - merr = err continue } if db.diskReadMeter != nil { @@ -315,15 +299,11 @@ func (db *DB) meter(refresh time.Duration) { // Sleep a bit, then repeat the stats collection select { - case errc = <-db.quitChan: + case <-db.quit: // Quit requesting, stop hammering the database + return case <-time.After(refresh): // Timeout, gather a new set of stats } } - - if errc == nil { - errc = <-db.quitChan - } - errc <- merr }