address comments.

Author: gatorsmile

sql/hive/src/main/scala/org/apache/spark/sql/hive/client/HiveClientImpl.scala

@@ -436,10 +436,7 @@ private[hive] class HiveClientImpl(
 
       val totalSize = properties.get(StatsSetupConst.TOTAL_SIZE).map(BigInt(_))
       val rawDataSize = properties.get(StatsSetupConst.RAW_DATA_SIZE).map(BigInt(_))
-      lazy val rowCount = properties.get(StatsSetupConst.ROW_COUNT).map(BigInt(_)) match {
-        case Some(c) if c >= 0 => Some(c)
-        case _ => None
-      }
+      val rowCount = properties.get(StatsSetupConst.ROW_COUNT).map(BigInt(_)).filter(_ >= 0)
       // TODO: check if this estimate is valid for tables after partition pruning.
       // NOTE: getting `totalSize` directly from params is kind of hacky, but this should be
       // relatively cheap if parameters for the table are populated into the metastore.

sql/hive/src/test/java/org/apache/spark/sql/hive/test/TestHiveSingleton.scala

@@ -19,13 +19,17 @@ package org.apache.spark.sql.hive.test
 
 import org.scalatest.BeforeAndAfterAll
 
-import org.apache.spark.sql.SparkSession
 import org.apache.spark.SparkFunSuite
+import org.apache.spark.sql.SparkSession
+import org.apache.spark.sql.hive.HiveExternalCatalog
+import org.apache.spark.sql.hive.client.HiveClient
 
 
 trait TestHiveSingleton extends SparkFunSuite with BeforeAndAfterAll {
   protected val spark: SparkSession = TestHive.sparkSession
   protected val hiveContext: TestHiveContext = TestHive
+  protected val hiveClient: HiveClient =
+    spark.sharedState.externalCatalog.asInstanceOf[HiveExternalCatalog].client
 
   protected override def afterAll(): Unit = {
     try {

sql/hive/src/test/scala/org/apache/spark/sql/hive/HiveDDLCommandSuite.scala

@@ -646,7 +646,6 @@ class HiveDDLCommandSuite extends PlanTest with SQLTestUtils with TestHiveSingle
   }
 
   test("SPARK-15887: hive-site.xml should be loaded") {
-    val hiveClient = spark.sharedState.externalCatalog.asInstanceOf[HiveExternalCatalog].client
     assert(hiveClient.getConf("hive.in.test", "") == "true")
   }
 

sql/hive/src/test/scala/org/apache/spark/sql/hive/HiveExternalCatalogBackwardCompatibilitySuite.scala

@@ -35,10 +35,6 @@ import org.apache.spark.util.Utils
 class HiveExternalCatalogBackwardCompatibilitySuite extends QueryTest
   with SQLTestUtils with TestHiveSingleton with BeforeAndAfterEach {
 
-  // To test `HiveExternalCatalog`, we need to read/write the raw table meta from/to hive client.
-  val hiveClient: HiveClient =
-    spark.sharedState.externalCatalog.asInstanceOf[HiveExternalCatalog].client
-
   val tempDir = Utils.createTempDir().getCanonicalFile
   val tempDirUri = tempDir.toURI
   val tempDirStr = tempDir.getAbsolutePath

sql/hive/src/test/scala/org/apache/spark/sql/hive/MetastoreDataSourcesSuite.scala

@@ -52,11 +52,6 @@ class MetastoreDataSourcesSuite extends QueryTest with SQLTestUtils with TestHiv
     jsonFilePath = Utils.getSparkClassLoader.getResource("sample.json").getFile
   }
 
-  // To test `HiveExternalCatalog`, we need to read the raw table metadata(schema, partition
-  // columns and bucket specification are still in table properties) from hive client.
-  private def hiveClient: HiveClient =
-    sharedState.externalCatalog.asInstanceOf[HiveExternalCatalog].client
-
   test("persistent JSON table") {
     withTable("jsonTable") {
       sql(

sql/hive/src/test/scala/org/apache/spark/sql/hive/StatisticsSuite.scala

@@ -222,7 +222,6 @@ class StatisticsSuite extends StatisticsCollectionTestBase with TestHiveSingleto
       tabName: String,
       analyzedBySpark: Boolean = true,
       analyzedByHive: Boolean = true): Unit = {
-    val hiveClient = spark.sharedState.externalCatalog.asInstanceOf[HiveExternalCatalog].client
     sql(
       s"""
          |CREATE TABLE $tabName (key STRING, value STRING)
@@ -277,7 +276,6 @@ class StatisticsSuite extends StatisticsCollectionTestBase with TestHiveSingleto
 
       // ALTER TABLE SET TBLPROPERTIES invalidates some contents of Hive specific statistics
       // This is triggered by the Hive alterTable API
-      val hiveClient = spark.sharedState.externalCatalog.asInstanceOf[HiveExternalCatalog].client
       val describeResult = hiveClient.runSqlHive(s"DESCRIBE FORMATTED $tabName")
 
       val rawDataSize = extractStatsPropValues(describeResult, "rawDataSize")
@@ -303,7 +301,6 @@ class StatisticsSuite extends StatisticsCollectionTestBase with TestHiveSingleto
         assert(fetchedStats1 == fetchedStats2)
 
         // ALTER TABLE RENAME does not affect the contents of Hive specific statistics
-        val hiveClient = spark.sharedState.externalCatalog.asInstanceOf[HiveExternalCatalog].client
         val describeResult = hiveClient.runSqlHive(s"DESCRIBE FORMATTED $newName")
 
         val rawDataSize = extractStatsPropValues(describeResult, "rawDataSize")
@@ -328,7 +325,6 @@ class StatisticsSuite extends StatisticsCollectionTestBase with TestHiveSingleto
           tabName, hasSizeInBytes = true, expectedRowCounts = Some(500))
         assert(fetchedStats1 == fetchedStats2)
 
-        val hiveClient = spark.sharedState.externalCatalog.asInstanceOf[HiveExternalCatalog].client
         val describeResult = hiveClient.runSqlHive(s"DESCRIBE FORMATTED $tabName")
 
         val totalSize = extractStatsPropValues(describeResult, "totalSize")
@@ -356,7 +352,6 @@ class StatisticsSuite extends StatisticsCollectionTestBase with TestHiveSingleto
           tabName, hasSizeInBytes = true, expectedRowCounts = Some(500))
         assert(fetchedStats1 == fetchedStats2)
 
-        val hiveClient = spark.sharedState.externalCatalog.asInstanceOf[HiveExternalCatalog].client
         val describeResult = hiveClient.runSqlHive(s"DESCRIBE FORMATTED $tabName")
 
         val totalSize = extractStatsPropValues(describeResult, "totalSize")
@@ -467,7 +462,6 @@ class StatisticsSuite extends StatisticsCollectionTestBase with TestHiveSingleto
       sql(s"analyze table $tableName compute STATISTICS FOR COLUMNS " + stats.keys.mkString(", "))
 
       // Validate statistics
-      val hiveClient = spark.sharedState.externalCatalog.asInstanceOf[HiveExternalCatalog].client
       val table = hiveClient.getTable("default", tableName)
 
       val props = table.properties.filterKeys(_.startsWith("spark.sql.statistics.colStats"))

sql/hive/src/test/scala/org/apache/spark/sql/hive/orc/OrcSourceSuite.scala

@@ -153,7 +153,6 @@ abstract class OrcSuite extends QueryTest with TestHiveSingleton with BeforeAndA
   }
 
   test("SPARK-19459/SPARK-18220: read char/varchar column written by Hive") {
-    val hiveClient = spark.sharedState.externalCatalog.asInstanceOf[HiveExternalCatalog].client
     val location = Utils.createTempDir()
     val uri = location.toURI
     try {