[SPARK-17738] [SQL] fix ARRAY/MAP in columnar cache

## What changes were proposed in this pull request?

The actualSize() of array and map is different from the actual size, the header is Int, rather than Long.

## How was this patch tested?

The flaky test should be fixed.

Author: Davies Liu <davies@databricks.com>

Closes #15305 from davies/fix_MAP.

sql/core/src/main/scala/org/apache/spark/sql/execution/columnar/ColumnType.scala

@@ -589,7 +589,7 @@ private[columnar] case class STRUCT(dataType: StructType)
 private[columnar] case class ARRAY(dataType: ArrayType)
   extends ColumnType[UnsafeArrayData] with DirectCopyColumnType[UnsafeArrayData] {
 
-  override def defaultSize: Int = 16
+  override def defaultSize: Int = 28
 
   override def setField(row: MutableRow, ordinal: Int, value: UnsafeArrayData): Unit = {
     row.update(ordinal, value)
@@ -601,7 +601,7 @@ private[columnar] case class ARRAY(dataType: ArrayType)
 
   override def actualSize(row: InternalRow, ordinal: Int): Int = {
     val unsafeArray = getField(row, ordinal)
-    8 + unsafeArray.getSizeInBytes
+    4 + unsafeArray.getSizeInBytes
   }
 
   override def append(value: UnsafeArrayData, buffer: ByteBuffer): Unit = {
@@ -628,7 +628,7 @@ private[columnar] case class ARRAY(dataType: ArrayType)
 private[columnar] case class MAP(dataType: MapType)
   extends ColumnType[UnsafeMapData] with DirectCopyColumnType[UnsafeMapData] {
 
-  override def defaultSize: Int = 32
+  override def defaultSize: Int = 68
 
   override def setField(row: MutableRow, ordinal: Int, value: UnsafeMapData): Unit = {
     row.update(ordinal, value)
@@ -640,7 +640,7 @@ private[columnar] case class MAP(dataType: MapType)
 
   override def actualSize(row: InternalRow, ordinal: Int): Int = {
     val unsafeMap = getField(row, ordinal)
-    8 + unsafeMap.getSizeInBytes
+    4 + unsafeMap.getSizeInBytes
   }
 
   override def append(value: UnsafeMapData, buffer: ByteBuffer): Unit = {

sql/core/src/test/scala/org/apache/spark/sql/execution/columnar/ColumnTypeSuite.scala

@@ -38,7 +38,7 @@ class ColumnTypeSuite extends SparkFunSuite with Logging {
     val checks = Map(
       NULL -> 0, BOOLEAN -> 1, BYTE -> 1, SHORT -> 2, INT -> 4, LONG -> 8,
       FLOAT -> 4, DOUBLE -> 8, COMPACT_DECIMAL(15, 10) -> 8, LARGE_DECIMAL(20, 10) -> 12,
-      STRING -> 8, BINARY -> 16, STRUCT_TYPE -> 20, ARRAY_TYPE -> 16, MAP_TYPE -> 32)
+      STRING -> 8, BINARY -> 16, STRUCT_TYPE -> 20, ARRAY_TYPE -> 28, MAP_TYPE -> 68)
 
     checks.foreach { case (columnType, expectedSize) =>
       assertResult(expectedSize, s"Wrong defaultSize for $columnType") {
@@ -73,8 +73,8 @@ class ColumnTypeSuite extends SparkFunSuite with Logging {
     checkActualSize(BINARY, Array.fill[Byte](4)(0.toByte), 4 + 4)
     checkActualSize(COMPACT_DECIMAL(15, 10), Decimal(0, 15, 10), 8)
     checkActualSize(LARGE_DECIMAL(20, 10), Decimal(0, 20, 10), 5)
-    checkActualSize(ARRAY_TYPE, Array[Any](1), 8 + 8 + 8 + 8)
-    checkActualSize(MAP_TYPE, Map(1 -> "a"), 8 + (8 + 8 + 8 + 8) + (8 + 8 + 8 + 8))
+    checkActualSize(ARRAY_TYPE, Array[Any](1), 4 + 8 + 8 + 8)
+    checkActualSize(MAP_TYPE, Map(1 -> "a"), 4 + (8 + 8 + 8 + 8) + (8 + 8 + 8 + 8))
     checkActualSize(STRUCT_TYPE, Row("hello"), 28)
   }