feat: delete radius in storage

portalnetwork/storage/content_storage.go

@@ -13,7 +13,6 @@ var MaxDistance = uint256.MustFromHex("0xfffffffffffffffffffffffffffffffffffffff
 
 type ContentType byte
 
-var RadisuKey = []byte("radius")
 var SizeKey = []byte("size")
 
 type ContentKey struct {

portalnetwork/storage/ethpepple/storage.go

@@ -1,6 +1,7 @@
 package ethpepple
 
 import (
+	"bytes"
 	"encoding/binary"
 	"runtime"
 	"sync/atomic"
@@ -139,28 +140,32 @@ func NewPeppleStorage(config PeppleStorageConfig) (storage.ContentStorage, error
 		writeOptions:           &pebble.WriteOptions{Sync: false},
 	}
 	cs.radius.Store(storage.MaxDistance)
-	radius, _, err := cs.db.Get(storage.RadisuKey)
+
+	val, _, err := cs.db.Get(storage.SizeKey)
 	if err != nil && err != pebble.ErrNotFound {
 		return nil, err
 	}
 	if err == nil {
+		size := binary.BigEndian.Uint64(val)
+		// init stage, no need to use lock
+		cs.size = size
+	}
+
+	iter, err := cs.db.NewIter(nil)
+	if err != nil {
+		return nil, err
+	}
+	defer iter.Close()
+	if iter.Last() && iter.Valid() {
+		distance := iter.Key()
 		dis := uint256.NewInt(0)
-		err = dis.UnmarshalSSZ(radius)
+		err = dis.UnmarshalSSZ(distance)
 		if err != nil {
 			return nil, err
 		}
 		cs.radius.Store(dis)
 	}
 
-	val, _, err := cs.db.Get(storage.SizeKey)
-	if err != nil && err != pebble.ErrNotFound {
-		return nil, err
-	}
-	if err == nil {
-		size := binary.BigEndian.Uint64(val)
-		// init stage, no need to use lock
-		cs.size = size
-	}
 	cs.sizeChan <- struct{}{}
 	go cs.saveCapacity()
 	return cs, nil
@@ -256,12 +261,14 @@ func (c *ContentStorage) prune() error {
 
 	batch := c.db.NewBatch()
 	for iter.Last(); iter.Valid(); iter.Prev() {
+		if bytes.Equal(iter.Key(), storage.SizeKey) {
+			continue
+		}
 		if curentSize < expectSize {
 			batch.Delete(iter.Key(), nil)
 			curentSize += uint64(len(iter.Key())) + uint64(len(iter.Value()))
 		} else {
 			distance := iter.Key()
-			c.db.Set(storage.RadisuKey, distance, c.writeOptions)
 			dis := uint256.NewInt(0)
 			err = dis.UnmarshalSSZ(distance)
 			if err != nil {