[#585] fstree: Add optional file counter

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

pkg/local_object_storage/writecache/writecachebbolt/state.go

@@ -2,20 +2,24 @@ package writecachebbolt
 
 import (
 	"fmt"
+	"math"
 	"sync/atomic"
-	"time"
 
-	"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/fstree"
 	"go.etcd.io/bbolt"
-	"go.uber.org/zap"
-	"golang.org/x/sync/errgroup"
 )
 
 func (c *cache) estimateCacheSize() uint64 {
-	db := c.objCounters.DB() * c.smallObjectSize
-	fstree := c.objCounters.FS() * c.maxObjectSize
-	c.metrics.SetEstimateSize(db, fstree)
-	return db + fstree
+	dbCount := c.objCounters.DB()
+	fsCount := c.objCounters.FS()
+	if fsCount > 0 {
+		fsCount-- //db file
+	}
+	dbSize := dbCount * c.smallObjectSize
+	fsSize := fsCount * c.maxObjectSize
+	c.metrics.SetEstimateSize(dbSize, fsSize)
+	c.metrics.SetActualCounters(dbCount, fsCount)
+	return dbSize + fsSize
 }
 
 func (c *cache) incSizeDB(sz uint64) uint64 {
@@ -26,6 +30,8 @@ func (c *cache) incSizeFS(sz uint64) uint64 {
 	return sz + c.maxObjectSize
 }
 
+var _ fstree.FileCounter = &counters{}
+
 type counters struct {
 	cDB, cFS atomic.Uint64
 }
@@ -38,60 +44,33 @@ func (x *counters) FS() uint64 {
 	return x.cFS.Load()
 }
 
-func (c *cache) setCounters() error {
+// Set implements fstree.ObjectCounter.
+func (x *counters) Set(v uint64) {
+	x.cFS.Store(v)
+}
+
+// Inc implements fstree.ObjectCounter.
+func (x *counters) Inc() {
+	x.cFS.Add(1)
+}
+
+// Dec implements fstree.ObjectCounter.
+func (x *counters) Dec() {
+	x.cFS.Add(math.MaxUint64)
+}
+
+func (c *cache) initCounters() error {
 	var inDB uint64
-	var inFS uint64
-
-	var eg errgroup.Group
-
-	eg.Go(func() error {
-		err := c.db.View(func(tx *bbolt.Tx) error {
-			b := tx.Bucket(defaultBucket)
-			if b != nil {
-				inDB = uint64(b.Stats().KeyN)
-			}
-			return nil
-		})
-		if err != nil {
-			return fmt.Errorf("could not read write-cache DB counter: %w", err)
+	err := c.db.View(func(tx *bbolt.Tx) error {
+		b := tx.Bucket(defaultBucket)
+		if b != nil {
+			inDB = uint64(b.Stats().KeyN)
 		}
-		c.objCounters.cDB.Store(inDB)
 		return nil
 	})
-
-	eg.Go(func() error {
-		var err error
-		inFS, err = c.fsTree.NumberOfObjects()
-		if err != nil {
-			return fmt.Errorf("could not read write-cache FS counter: %w", err)
-		}
-		if inFS > 0 {
-			inFS-- //small.bolt DB file
-		}
-		c.objCounters.cFS.Store(inFS)
-		return nil
-	})
-	if err := eg.Wait(); err != nil {
-		return err
+	if err != nil {
+		return fmt.Errorf("could not read write-cache DB counter: %w", err)
 	}
-	c.metrics.SetActualCounters(inDB, inFS)
+	c.objCounters.cDB.Store(inDB)
 	return nil
 }
-
-func (c *cache) runDBCounterLoop() {
-	go func() {
-		t := time.NewTicker(time.Second * 30)
-		defer t.Stop()
-		for {
-			select {
-			case <-t.C:
-				err := c.setCounters()
-				if err != nil {
-					c.log.Warn(logs.FailedToCountWritecacheItems, zap.Error(err))
-				}
-			case <-c.closeCh:
-				return
-			}
-		}
-	}()
-}