[blocksync] remove redundant clean-up (#4505)

blocksync/blocksync.go

@@ -290,7 +290,6 @@ func (bs *blockSyncer) ProcessBlock(ctx context.Context, peer string, blk *block
 		}
 		syncedHeight++
 	}
-	bs.buf.Cleanup(syncedHeight)
 	log.L().Debug("flush blocks", zap.Uint64("start", tip), zap.Uint64("end", syncedHeight))
 	if syncedHeight > bs.lastTip {
 		bs.lastTip = syncedHeight

blocksync/buffer.go

@@ -7,10 +7,6 @@ package blocksync
 
 import (
 	"sync"
-
-	"go.uber.org/zap"
-
-	"github.com/iotexproject/iotex-core/v2/pkg/log"
 )
 
 // blockBuffer is used to keep in-coming block in order.
@@ -47,23 +43,6 @@ func (b *blockBuffer) Pop(height uint64) []*peerBlock {
 	return blks
 }
 
-func (b *blockBuffer) Cleanup(height uint64) {
-	b.mu.Lock()
-	defer b.mu.Unlock()
-
-	size := len(b.blockQueues)
-	if size > int(b.bufferSize)*2 {
-		log.L().Warn("blockBuffer is leaking memory.", zap.Int("bufferSize", size))
-		newQueues := map[uint64]*uniQueue{}
-		for h := range b.blockQueues {
-			if h > height {
-				newQueues[h] = b.blockQueues[h]
-			}
-		}
-		b.blockQueues = newQueues
-	}
-}
-
 // AddBlock tries to put given block into buffer and flush buffer into blockchain.
 func (b *blockBuffer) AddBlock(tipHeight uint64, blk *peerBlock) (bool, uint64) {
 	b.mu.Lock()