[#1668] writecache: Use object size to check free space

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

pkg/local_object_storage/writecache/put.go

@@ -2,6 +2,7 @@ package writecache
 
 import (
 	"context"
+	"fmt"
 	"time"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
@@ -59,7 +60,15 @@ func (c *cache) Put(ctx context.Context, prm common.PutPrm) (common.PutRes, erro
 
 // putBig writes object to FSTree and pushes it to the flush workers queue.
 func (c *cache) putBig(ctx context.Context, prm common.PutPrm) error {
-	if !c.hasEnoughSpaceFS() {
+	if prm.RawData == nil { // foolproof: RawData should be marshalled by shard.
+		data, err := prm.Object.Marshal()
+		if err != nil {
+			return fmt.Errorf("cannot marshal object: %w", err)
+		}
+		prm.RawData = data
+	}
+	size := uint64(len(prm.RawData))
+	if !c.hasEnoughSpace(size) {
 		return ErrOutOfSpace
 	}