[SPARK-13076][SQL] Rename ClientInterface -> HiveClient

And ClientWrapper -> HiveClientImpl.

I have some followup pull requests to introduce a new internal catalog, and I think this new naming reflects better the functionality of the two classes.

Author: Reynold Xin <rxin@databricks.com>

Closes #10981 from rxin/SPARK-13076.

sql/core/src/main/scala/org/apache/spark/sql/execution/commands.scala

@@ -404,7 +404,7 @@ case class DescribeFunction(
           result
         }
 
-      case None => Seq(Row(s"Function: $functionName is not found."))
+      case None => Seq(Row(s"Function: $functionName not found."))
     }
   }
 }

sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala

@@ -84,7 +84,7 @@ class SQLQuerySuite extends QueryTest with SharedSQLContext {
       "Extended Usage")
 
     checkExistence(sql("describe functioN abcadf"), true,
-      "Function: abcadf is not found.")
+      "Function: abcadf not found.")
   }
 
   test("SPARK-6743: no columns from cache") {

sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveContext.scala

@@ -79,8 +79,8 @@ class HiveContext private[hive](
     sc: SparkContext,
     cacheManager: CacheManager,
     listener: SQLListener,
-    @transient private val execHive: ClientWrapper,
+    @transient private val execHive: HiveClientImpl,
-    @transient private val metaHive: ClientInterface,
+    @transient private val metaHive: HiveClient,
     isRootContext: Boolean)
   extends SQLContext(sc, cacheManager, listener, isRootContext) with Logging {
   self =>
@@ -193,7 +193,7 @@ class HiveContext private[hive](
    * for storing persistent metadata, and only point to a dummy metastore in a temporary directory.
    */
   @transient
-  protected[hive] lazy val executionHive: ClientWrapper = if (execHive != null) {
+  protected[hive] lazy val executionHive: HiveClientImpl = if (execHive != null) {
     execHive
   } else {
     logInfo(s"Initializing execution hive, version $hiveExecutionVersion")
@@ -203,7 +203,7 @@ class HiveContext private[hive](
       config = newTemporaryConfiguration(useInMemoryDerby = true),
       isolationOn = false,
       baseClassLoader = Utils.getContextOrSparkClassLoader)
-    loader.createClient().asInstanceOf[ClientWrapper]
+    loader.createClient().asInstanceOf[HiveClientImpl]
   }
 
   /**
@@ -222,7 +222,7 @@ class HiveContext private[hive](
    * in the hive-site.xml file.
    */
   @transient
-  protected[hive] lazy val metadataHive: ClientInterface = if (metaHive != null) {
+  protected[hive] lazy val metadataHive: HiveClient = if (metaHive != null) {
     metaHive
   } else {
     val metaVersion = IsolatedClientLoader.hiveVersion(hiveMetastoreVersion)

sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveMetastoreCatalog.scala

@@ -96,7 +96,7 @@ private[hive] object HiveSerDe {
   }
 }
 
-private[hive] class HiveMetastoreCatalog(val client: ClientInterface, hive: HiveContext)
+private[hive] class HiveMetastoreCatalog(val client: HiveClient, hive: HiveContext)
   extends Catalog with Logging {
 
   val conf = hive.conf

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

@@ -60,9 +60,9 @@ private[hive] case class HiveTable(
     viewText: Option[String] = None) {
 
   @transient
-  private[client] var client: ClientInterface = _
+  private[client] var client: HiveClient = _
 
-  private[client] def withClient(ci: ClientInterface): this.type = {
+  private[client] def withClient(ci: HiveClient): this.type = {
     client = ci
     this
   }
@@ -85,7 +85,7 @@ private[hive] case class HiveTable(
  * internal and external classloaders for a given version of Hive and thus must expose only
  * shared classes.
  */
-private[hive] trait ClientInterface {
+private[hive] trait HiveClient {
 
   /** Returns the Hive Version of this client. */
   def version: HiveVersion
@@ -184,8 +184,8 @@ private[hive] trait ClientInterface {
   /** Add a jar into class loader */
   def addJar(path: String): Unit
 
-  /** Return a ClientInterface as new session, that will share the class loader and Hive client */
+  /** Return a [[HiveClient]] as new session, that will share the class loader and Hive client */
-  def newSession(): ClientInterface
+  def newSession(): HiveClient
 
   /** Run a function within Hive state (SessionState, HiveConf, Hive client and class loader) */
   def withHiveState[A](f: => A): A

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

@@ -44,8 +44,8 @@ import org.apache.spark.util.{CircularBuffer, Utils}
  * A class that wraps the HiveClient and converts its responses to externally visible classes.
  * Note that this class is typically loaded with an internal classloader for each instantiation,
  * allowing it to interact directly with a specific isolated version of Hive.  Loading this class
- * with the isolated classloader however will result in it only being visible as a ClientInterface,
+ * with the isolated classloader however will result in it only being visible as a [[HiveClient]],
- * not a ClientWrapper.
+ * not a [[HiveClientImpl]].
  *
  * This class needs to interact with multiple versions of Hive, but will always be compiled with
  * the 'native', execution version of Hive.  Therefore, any places where hive breaks compatibility
@@ -55,14 +55,14 @@ import org.apache.spark.util.{CircularBuffer, Utils}
  * @param config  a collection of configuration options that will be added to the hive conf before
  *                opening the hive client.
  * @param initClassLoader the classloader used when creating the `state` field of
- *                        this ClientWrapper.
+ *                        this [[HiveClientImpl]].
  */
-private[hive] class ClientWrapper(
+private[hive] class HiveClientImpl(
     override val version: HiveVersion,
     config: Map[String, String],
     initClassLoader: ClassLoader,
     val clientLoader: IsolatedClientLoader)
-  extends ClientInterface
+  extends HiveClient
   with Logging {
 
   // Circular buffer to hold what hive prints to STDOUT and ERR.  Only printed when failures occur.
@@ -77,7 +77,7 @@ private[hive] class ClientWrapper(
     case hive.v1_2 => new Shim_v1_2()
   }
 
-  // Create an internal session state for this ClientWrapper.
+  // Create an internal session state for this HiveClientImpl.
   val state = {
     val original = Thread.currentThread().getContextClassLoader
     // Switch to the initClassLoader.
@@ -160,7 +160,7 @@ private[hive] class ClientWrapper(
         case e: Exception if causedByThrift(e) =>
           caughtException = e
           logWarning(
-            "HiveClientWrapper got thrift exception, destroying client and retrying " +
+            "HiveClient got thrift exception, destroying client and retrying " +
               s"(${retryLimit - numTries} tries remaining)", e)
           clientLoader.cachedHive = null
           Thread.sleep(retryDelayMillis)
@@ -199,7 +199,7 @@ private[hive] class ClientWrapper(
    */
   def withHiveState[A](f: => A): A = retryLocked {
     val original = Thread.currentThread().getContextClassLoader
-    // Set the thread local metastore client to the client associated with this ClientWrapper.
+    // Set the thread local metastore client to the client associated with this HiveClientImpl.
     Hive.set(client)
     // The classloader in clientLoader could be changed after addJar, always use the latest
     // classloader
@@ -521,8 +521,8 @@ private[hive] class ClientWrapper(
     runSqlHive(s"ADD JAR $path")
   }
 
-  def newSession(): ClientWrapper = {
+  def newSession(): HiveClientImpl = {
-    clientLoader.createClient().asInstanceOf[ClientWrapper]
+    clientLoader.createClient().asInstanceOf[HiveClientImpl]
   }
 
   def reset(): Unit = withHiveState {

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

@@ -38,8 +38,8 @@ import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.types.{IntegralType, StringType}
 
 /**
- * A shim that defines the interface between ClientWrapper and the underlying Hive library used to
+ * A shim that defines the interface between [[HiveClientImpl]] and the underlying Hive library used
- * talk to the metastore. Each Hive version has its own implementation of this class, defining
+ * to talk to the metastore. Each Hive version has its own implementation of this class, defining
  * version-specific version of needed functions.
  *
  * The guideline for writing shims is:
@@ -52,7 +52,6 @@ private[client] sealed abstract class Shim {
   /**
    * Set the current SessionState to the given SessionState. Also, set the context classloader of
    * the current thread to the one set in the HiveConf of this given `state`.
-   * @param state
    */
   def setCurrentSessionState(state: SessionState): Unit
 

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

@@ -124,15 +124,15 @@ private[hive] object IsolatedClientLoader extends Logging {
 }
 
 /**
- * Creates a Hive `ClientInterface` using a classloader that works according to the following rules:
+ * Creates a [[HiveClient]] using a classloader that works according to the following rules:
  *  - Shared classes: Java, Scala, logging, and Spark classes are delegated to `baseClassLoader`
- *    allowing the results of calls to the `ClientInterface` to be visible externally.
+ *    allowing the results of calls to the [[HiveClient]] to be visible externally.
  *  - Hive classes: new instances are loaded from `execJars`.  These classes are not
  *    accessible externally due to their custom loading.
- *  - ClientWrapper: a new copy is created for each instance of `IsolatedClassLoader`.
+ *  - [[HiveClientImpl]]: a new copy is created for each instance of `IsolatedClassLoader`.
  *    This new instance is able to see a specific version of hive without using reflection. Since
  *    this is a unique instance, it is not visible externally other than as a generic
- *    `ClientInterface`, unless `isolationOn` is set to `false`.
+ *    [[HiveClient]], unless `isolationOn` is set to `false`.
  *
  * @param version The version of hive on the classpath.  used to pick specific function signatures
  *                that are not compatible across versions.
@@ -179,7 +179,7 @@ private[hive] class IsolatedClientLoader(
 
   /** True if `name` refers to a spark class that must see specific version of Hive. */
   protected def isBarrierClass(name: String): Boolean =
-    name.startsWith(classOf[ClientWrapper].getName) ||
+    name.startsWith(classOf[HiveClientImpl].getName) ||
     name.startsWith(classOf[Shim].getName) ||
     barrierPrefixes.exists(name.startsWith)
 
@@ -233,9 +233,9 @@ private[hive] class IsolatedClientLoader(
   }
 
   /** The isolated client interface to Hive. */
-  private[hive] def createClient(): ClientInterface = {
+  private[hive] def createClient(): HiveClient = {
     if (!isolationOn) {
-      return new ClientWrapper(version, config, baseClassLoader, this)
+      return new HiveClientImpl(version, config, baseClassLoader, this)
     }
     // Pre-reflective instantiation setup.
     logDebug("Initializing the logger to avoid disaster...")
@@ -244,10 +244,10 @@ private[hive] class IsolatedClientLoader(
 
     try {
       classLoader
-        .loadClass(classOf[ClientWrapper].getName)
+        .loadClass(classOf[HiveClientImpl].getName)
         .getConstructors.head
         .newInstance(version, config, classLoader, this)
-        .asInstanceOf[ClientInterface]
+        .asInstanceOf[HiveClient]
     } catch {
       case e: InvocationTargetException =>
         if (e.getCause().isInstanceOf[NoClassDefFoundError]) {

sql/hive/src/main/scala/org/apache/spark/sql/hive/hiveUDFs.scala

@@ -38,13 +38,13 @@ import org.apache.spark.sql.catalyst.expressions.aggregate._
 import org.apache.spark.sql.catalyst.expressions.codegen.CodegenFallback
 import org.apache.spark.sql.catalyst.util.sequenceOption
 import org.apache.spark.sql.hive.HiveShim._
-import org.apache.spark.sql.hive.client.ClientWrapper
+import org.apache.spark.sql.hive.client.HiveClientImpl
 import org.apache.spark.sql.types._
 
 
 private[hive] class HiveFunctionRegistry(
     underlying: analysis.FunctionRegistry,
-    executionHive: ClientWrapper)
+    executionHive: HiveClientImpl)
   extends analysis.FunctionRegistry with HiveInspectors {
 
   def getFunctionInfo(name: String): FunctionInfo = {

sql/hive/src/main/scala/org/apache/spark/sql/hive/test/TestHive.scala

@@ -37,7 +37,7 @@ import org.apache.spark.sql.catalyst.expressions.ExpressionInfo
 import org.apache.spark.sql.catalyst.plans.logical.LogicalPlan
 import org.apache.spark.sql.execution.CacheTableCommand
 import org.apache.spark.sql.hive._
-import org.apache.spark.sql.hive.client.ClientWrapper
+import org.apache.spark.sql.hive.client.HiveClientImpl
 import org.apache.spark.sql.hive.execution.HiveNativeCommand
 import org.apache.spark.util.{ShutdownHookManager, Utils}
 
@@ -458,7 +458,7 @@ class TestHiveContext(sc: SparkContext) extends HiveContext(sc) {
     org.apache.spark.sql.catalyst.analysis.FunctionRegistry.builtin.copy(), this.executionHive)
 }
 
-private[hive] class TestHiveFunctionRegistry(fr: SimpleFunctionRegistry, client: ClientWrapper)
+private[hive] class TestHiveFunctionRegistry(fr: SimpleFunctionRegistry, client: HiveClientImpl)
   extends HiveFunctionRegistry(fr, client) {
 
   private val removedFunctions =

sql/hive/src/test/scala/org/apache/spark/sql/hive/client/VersionsSuite.scala

@@ -30,7 +30,7 @@ import org.apache.spark.tags.ExtendedHiveTest
 import org.apache.spark.util.Utils
 
 /**
- * A simple set of tests that call the methods of a hive ClientInterface, loading different version
+ * A simple set of tests that call the methods of a [[HiveClient]], loading different version
  * of hive from maven central.  These tests are simple in that they are mostly just testing to make
  * sure that reflective calls are not throwing NoSuchMethod error, but the actually functionality
  * is not fully tested.
@@ -101,7 +101,7 @@ class VersionsSuite extends SparkFunSuite with Logging {
 
   private val versions = Seq("12", "13", "14", "1.0.0", "1.1.0", "1.2.0")
 
-  private var client: ClientInterface = null
+  private var client: HiveClient = null
 
   versions.foreach { version =>
     test(s"$version: create client") {

sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/SQLQuerySuite.scala

@@ -199,7 +199,7 @@ class SQLQuerySuite extends QueryTest with SQLTestUtils with TestHiveSingleton {
       "Extended Usage")
 
     checkExistence(sql("describe functioN abcadf"), true,
-      "Function: abcadf is not found.")
+      "Function: abcadf not found.")
 
     checkExistence(sql("describe functioN  `~`"), true,
       "Function: ~",