Refactor CatalogFunction to use FunctionIdentifier

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/TableIdentifier.scala

@@ -40,14 +40,14 @@ private[sql] object TableIdentifier {
  * If `database` is not defined, the current database is used.
  */
 // TODO: reuse some code with TableIdentifier.
-private[sql] case class FunctionIdentifier(name: String, database: Option[String]) {
+private[sql] case class FunctionIdentifier(funcName: String, database: Option[String]) {
   def this(name: String) = this(name, None)
 
   override def toString: String = quotedString
 
-  def quotedString: String = database.map(db => s"`$db`.`$name`").getOrElse(s"`$name`")
+  def quotedString: String = database.map(db => s"`$db`.`$funcName`").getOrElse(s"`$funcName`")
 
-  def unquotedString: String = database.map(db => s"$db.$name").getOrElse(name)
+  def unquotedString: String = database.map(db => s"$db.$funcName").getOrElse(funcName)
 }
 
 private[sql] object FunctionIdentifier {

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/InMemoryCatalog.scala

@@ -20,7 +20,7 @@ package org.apache.spark.sql.catalyst.catalog
 import scala.collection.mutable
 
 import org.apache.spark.sql.AnalysisException
-import org.apache.spark.sql.catalyst.TableIdentifier
+import org.apache.spark.sql.catalyst.{FunctionIdentifier, TableIdentifier}
 
 
 /**
@@ -294,10 +294,10 @@ class InMemoryCatalog extends ExternalCatalog {
 
   override def createFunction(db: String, func: CatalogFunction): Unit = synchronized {
     requireDbExists(db)
-    if (existsFunction(db, func.name)) {
+    if (existsFunction(db, func.name.funcName)) {
       throw new AnalysisException(s"Function $func already exists in $db database")
     } else {
-      catalog(db).functions.put(func.name, func)
+      catalog(db).functions.put(func.name.funcName, func)
     }
   }
 
@@ -308,14 +308,14 @@ class InMemoryCatalog extends ExternalCatalog {
 
   override def renameFunction(db: String, oldName: String, newName: String): Unit = synchronized {
     requireFunctionExists(db, oldName)
-    val newFunc = getFunction(db, oldName).copy(name = newName)
+    val newFunc = getFunction(db, oldName).copy(name = FunctionIdentifier(newName, Some(db)))
     catalog(db).functions.remove(oldName)
     catalog(db).functions.put(newName, newFunc)
   }
 
   override def alterFunction(db: String, funcDefinition: CatalogFunction): Unit = synchronized {
-    requireFunctionExists(db, funcDefinition.name)
-    catalog(db).functions.put(funcDefinition.name, funcDefinition)
+    requireFunctionExists(db, funcDefinition.name.funcName)
+    catalog(db).functions.put(funcDefinition.name.funcName, funcDefinition)
   }
 
   override def getFunction(db: String, funcName: String): CatalogFunction = synchronized {

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/interface.scala

@@ -168,8 +168,7 @@ abstract class ExternalCatalog {
  * @param name name of the function
  * @param className fully qualified class name, e.g. "org.apache.spark.util.MyFunc"
  */
-// TODO: use FunctionIdentifier here.
-case class CatalogFunction(name: String, className: String)
+case class CatalogFunction(name: FunctionIdentifier, className: String)
 
 
 /**

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/catalog/CatalogTestCases.scala

@@ -21,7 +21,7 @@ import org.scalatest.BeforeAndAfterEach
 
 import org.apache.spark.SparkFunSuite
 import org.apache.spark.sql.AnalysisException
-import org.apache.spark.sql.catalyst.TableIdentifier
+import org.apache.spark.sql.catalyst.{FunctionIdentifier, TableIdentifier}
 
 
 /**
@@ -82,7 +82,7 @@ abstract class CatalogTestCases extends SparkFunSuite with BeforeAndAfterEach {
     catalog
   }
 
-  private def newFunc(): CatalogFunction = CatalogFunction("funcname", funcClass)
+  private def newFunc(): CatalogFunction = newFunc("funcName")
 
   private def newDb(name: String): CatalogDatabase = {
     CatalogDatabase(name, name + " description", newUriForDatabase(), Map.empty)
@@ -97,7 +97,9 @@ abstract class CatalogTestCases extends SparkFunSuite with BeforeAndAfterEach {
       partitionColumns = Seq(CatalogColumn("a", "int"), CatalogColumn("b", "string")))
   }
 
-  private def newFunc(name: String): CatalogFunction = CatalogFunction(name, funcClass)
+  private def newFunc(name: String): CatalogFunction = {
+    CatalogFunction(FunctionIdentifier(name, database = None), funcClass)
+  }
 
   /**
    * Whether the catalog's table partitions equal the ones given.
@@ -498,7 +500,8 @@ abstract class CatalogTestCases extends SparkFunSuite with BeforeAndAfterEach {
 
   test("get function") {
     val catalog = newBasicCatalog()
-    assert(catalog.getFunction("db2", "func1") == newFunc("func1"))
+    assert(catalog.getFunction("db2", "func1") ==
+      CatalogFunction(FunctionIdentifier("func1", Some("db2")), funcClass))
     intercept[AnalysisException] {
       catalog.getFunction("db2", "does_not_exist")
     }
@@ -517,7 +520,7 @@ abstract class CatalogTestCases extends SparkFunSuite with BeforeAndAfterEach {
     assert(catalog.getFunction("db2", "func1").className == funcClass)
     catalog.renameFunction("db2", "func1", newName)
     intercept[AnalysisException] { catalog.getFunction("db2", "func1") }
-    assert(catalog.getFunction("db2", newName).name == newName)
+    assert(catalog.getFunction("db2", newName).name.funcName == newName)
     assert(catalog.getFunction("db2", newName).className == funcClass)
     intercept[AnalysisException] { catalog.renameFunction("db2", "does_not_exist", "me") }
   }

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

@@ -35,7 +35,7 @@ import org.apache.hadoop.hive.ql.session.SessionState
 import org.apache.hadoop.security.UserGroupInformation
 
 import org.apache.spark.{Logging, SparkConf, SparkException}
-import org.apache.spark.sql.catalyst.TableIdentifier
+import org.apache.spark.sql.catalyst.{FunctionIdentifier, TableIdentifier}
 import org.apache.spark.sql.catalyst.analysis.{NoSuchDatabaseException, NoSuchPartitionException}
 import org.apache.spark.sql.catalyst.catalog._
 import org.apache.spark.sql.catalyst.expressions.Expression
@@ -545,13 +545,13 @@ private[hive] class HiveClientImpl(
   }
 
   override def renameFunction(db: String, oldName: String, newName: String): Unit = withHiveState {
-    val catalogFunc = getFunction(db, oldName).copy(name = newName)
+    val catalogFunc = getFunction(db, oldName).copy(name = FunctionIdentifier(newName, Some(db)))
     val hiveFunc = toHiveFunction(catalogFunc, db)
     client.alterFunction(db, oldName, hiveFunc)
   }
 
   override def alterFunction(db: String, func: CatalogFunction): Unit = withHiveState {
-    client.alterFunction(db, func.name, toHiveFunction(func, db))
+    client.alterFunction(db, func.name.funcName, toHiveFunction(func, db))
   }
 
   override def getFunctionOption(
@@ -612,7 +612,7 @@ private[hive] class HiveClientImpl(
 
   private def toHiveFunction(f: CatalogFunction, db: String): HiveFunction = {
     new HiveFunction(
-      f.name,
+      f.name.funcName,
       db,
       f.className,
       null,
@@ -623,7 +623,8 @@ private[hive] class HiveClientImpl(
   }
 
   private def fromHiveFunction(hf: HiveFunction): CatalogFunction = {
-    new CatalogFunction(hf.getFunctionName, hf.getClassName)
+    val name = FunctionIdentifier(hf.getFunctionName, Option(hf.getDbName))
+    new CatalogFunction(name, hf.getClassName)
   }
 
   private def toHiveColumn(c: CatalogColumn): FieldSchema = {