do not change existing code

Author: liutang123

sql/core/src/main/scala/org/apache/spark/sql/execution/joins/HashedRelation.scala

@@ -726,10 +726,9 @@ private[execution] final class LongToUnsafeRowMap(val mm: TaskMemoryManager, cap
 
     writeLong(array.length)
     writeLongArray(writeBuffer, array, array.length)
-
-    val usedWordsNumber = ((cursor - Platform.LONG_ARRAY_OFFSET) / 8).toInt
-    writeLong(usedWordsNumber)
-    writeLongArray(writeBuffer, page, usedWordsNumber)
+    val used = ((cursor - Platform.LONG_ARRAY_OFFSET) / 8).toInt
+    writeLong(used)
+    writeLongArray(writeBuffer, page, used)
   }
 
   override def writeExternal(output: ObjectOutput): Unit = {
@@ -771,10 +770,10 @@ private[execution] final class LongToUnsafeRowMap(val mm: TaskMemoryManager, cap
     val length = readLong().toInt
     mask = length - 2
     array = readLongArray(readBuffer, length)
-    val usedWordsNumber = readLong().toInt
+    val pageLength = readLong().toInt
+    page = readLongArray(readBuffer, pageLength)
     // Set cursor because cursor is used in write function.
-    cursor = usedWordsNumber * 8 + Platform.LONG_ARRAY_OFFSET
-    page = readLongArray(readBuffer, usedWordsNumber)
+    cursor = pageLength * 8 + Platform.LONG_ARRAY_OFFSET
   }
 
   override def readExternal(in: ObjectInput): Unit = {