Optimize copying goroutine (#253)

db.go

@@ -800,33 +800,33 @@ func (db *DB) copyNodes(
 			return err
 		}
 
-		for wr := req.WALRequest; wr != nil; wr = wr.Next {
-			walNode := waltypes.ProjectNode(db.config.State.Node(wr.NodeAddress))
-			var wrIndex uint16
-
-			for wrIndex < waltypes.BlobSize && wal.RecordType(walNode.Blob[wrIndex]) != wal.RecordEnd {
-				switch recordType := wal.RecordType(walNode.Blob[wrIndex]); recordType {
-				case wal.RecordSet1:
-					wrIndex += 10
-				case wal.RecordSet8:
-					wrIndex += 17
-				case wal.RecordSet32:
-					wrIndex += 41
-				case wal.RecordSet:
-					wrIndex += 9
-					wrIndex += *(*uint16)(unsafe.Pointer(&walNode.Blob[wrIndex])) + 2
-				case wal.RecordImmediateDeallocation, wal.RecordDelayedDeallocation:
-					wrIndex++
-					oldNodeAddress := *(*types.NodeAddress)(unsafe.Pointer(&walNode.Blob[wrIndex+8]))
-					newNodeAddress := *(*types.NodeAddress)(unsafe.Pointer(&walNode.Blob[wrIndex+16]))
-					wrIndex += 24
+		if processedCount&3 == mod {
+			for wr := req.WALRequest; wr != nil; wr = wr.Next {
+				walNode := waltypes.ProjectNode(db.config.State.Node(wr.NodeAddress))
+				var wrIndex uint16
+
+				for wrIndex < waltypes.BlobSize && wal.RecordType(walNode.Blob[wrIndex]) != wal.RecordEnd {
+					switch recordType := wal.RecordType(walNode.Blob[wrIndex]); recordType {
+					case wal.RecordSet1:
+						wrIndex += 10
+					case wal.RecordSet8:
+						wrIndex += 17
+					case wal.RecordSet32:
+						wrIndex += 41
+					case wal.RecordSet:
+						wrIndex += 9
+						wrIndex += *(*uint16)(unsafe.Pointer(&walNode.Blob[wrIndex])) + 2
+					case wal.RecordImmediateDeallocation, wal.RecordDelayedDeallocation:
+						wrIndex++
+						oldNodeAddress := *(*types.NodeAddress)(unsafe.Pointer(&walNode.Blob[wrIndex+8]))
+						newNodeAddress := *(*types.NodeAddress)(unsafe.Pointer(&walNode.Blob[wrIndex+16]))
+						wrIndex += 24
 
-					if uint64(newNodeAddress)&3 == mod {
 						copy(db.config.State.Bytes(newNodeAddress), db.config.State.Bytes(oldNodeAddress))
+					default:
+						fmt.Printf("%#v\n", walNode.Blob)
+						panic("=============")
 					}
-				default:
-					fmt.Printf("%#v\n", walNode.Blob)
-					panic("=============")
 				}
 			}
 		}