remove unnecessary func

db/db.go

@@ -1,9 +1,6 @@
 package db
 
 import (
-	"fmt"
-	"strconv"
-	"strings"
 	"sync"
 	"time"
 
@@ -128,157 +125,7 @@ func (db *LDBDatabase) LDB() *leveldb.DB {
 	return db.db
 }
 
-// meter periodically retrieves internal leveldb counters and reports them to
+// TODO(minhdoan): Might add meter func from ethereum-go repo
-// 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
-//
-// This is how the write delay look like (currently):
-// DelayN:5 Delay:406.604657ms Paused: false
-//
-// This is how the iostats look like (currently):
-// Read(MB):3895.04860 Write(MB):3654.64712
-func (db *LDBDatabase) meter(refresh time.Duration) {
-	// Create the counters to store current and previous compaction values
-	compactions := make([][]float64, 2)
-	for i := 0; i < 2; i++ {
-		compactions[i] = make([]float64, 3)
-	}
-	// Create storage for iostats.
-	var iostats [2]float64
-
-	// Create storage and warning log tracer for write delay.
-	var (
-		delaystats      [2]int64
-		lastWritePaused time.Time
-	)
-
-	var (
-		errc chan error
-		merr error
-	)
-
-	// Iterate ad infinitum and collect the stats
-	for i := 1; errc == nil && merr == nil; i++ {
-		// Retrieve the database stats
-		stats, err := db.db.GetProperty("leveldb.stats")
-		if err != nil {
-			db.log.Error("Failed to read database stats", "err", err)
-			merr = err
-			continue
-		}
-		// 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 {
-			db.log.Error("Compaction table not found")
-			merr = errors.New("compaction table not found")
-			continue
-		}
-		lines = lines[3:]
-
-		// Iterate over all the table rows, and accumulate the entries
-		for j := 0; j < len(compactions[i%2]); j++ {
-			compactions[i%2][j] = 0
-		}
-		for _, line := range lines {
-			parts := strings.Split(line, "|")
-			if len(parts) != 6 {
-				break
-			}
-			for idx, counter := range parts[3:] {
-				value, err := strconv.ParseFloat(strings.TrimSpace(counter), 64)
-				if err != nil {
-					db.log.Error("Compaction entry parsing failed", "err", err)
-					merr = err
-					continue
-				}
-				compactions[i%2][idx] += value
-			}
-		}
-
-		// Retrieve the write delay statistic
-		writedelay, err := db.db.GetProperty("leveldb.writedelay")
-		if err != nil {
-			db.log.Error("Failed to read database write delay statistic", "err", err)
-			merr = err
-			continue
-		}
-		var (
-			delayN        int64
-			delayDuration string
-			duration      time.Duration
-			paused        bool
-		)
-		if n, err := fmt.Sscanf(writedelay, "DelayN:%d Delay:%s Paused:%t", &delayN, &delayDuration, &paused); n != 3 || err != nil {
-			db.log.Error("Write delay statistic not found")
-			merr = err
-			continue
-		}
-		duration, err = time.ParseDuration(delayDuration)
-		if err != nil {
-			db.log.Error("Failed to parse delay duration", "err", err)
-			merr = err
-			continue
-		}
-		// If a warning that db is performing compaction has been displayed, any subsequent
-		// warnings will be withheld for one minute not to overwhelm the user.
-		if paused && delayN-delaystats[0] == 0 && duration.Nanoseconds()-delaystats[1] == 0 &&
-			time.Now().After(lastWritePaused.Add(writePauseWarningThrottler)) {
-			db.log.Warn("Database compacting, degraded performance")
-			lastWritePaused = time.Now()
-		}
-		delaystats[0], delaystats[1] = delayN, duration.Nanoseconds()
-
-		// Retrieve the database iostats.
-		ioStats, err := db.db.GetProperty("leveldb.iostats")
-		if err != nil {
-			db.log.Error("Failed to read database iostats", "err", err)
-			merr = err
-			continue
-		}
-		var nRead, nWrite float64
-		parts := strings.Split(ioStats, " ")
-		if len(parts) < 2 {
-			db.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 {
-			db.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 {
-			db.log.Error("Bad syntax of write entry", "entry", parts[1])
-			merr = err
-			continue
-		}
-		iostats[0], iostats[1] = nRead, nWrite
-
-		// Sleep a bit, then repeat the stats collection
-		select {
-		case errc = <-db.quitChan:
-			// Quit requesting, stop hammering the database
-		case <-time.After(refresh):
-			// Timeout, gather a new set of stats
-		}
-	}
-
-	if errc == nil {
-		errc = <-db.quitChan
-	}
-	errc <- merr
-}
 
 func (db *LDBDatabase) NewBatch() Batch {
 	return &ldbBatch{db: db.db, b: new(leveldb.Batch)}