[SPARK-14487][SQL] User Defined Type registration without SQLUserDefinedType annotation

## What changes were proposed in this pull request?

Currently we use `SQLUserDefinedType` annotation to register UDTs for user classes. However, by doing this, we add Spark dependency to user classes.

For some user classes, it is unnecessary to add such dependency that will increase deployment difficulty.

We should provide alternative approach to register UDTs for user classes without `SQLUserDefinedType` annotation.

## How was this patch tested?

`UserDefinedTypeSuite`

Author: Liang-Chi Hsieh <simonh@tw.ibm.com>

Closes #12259 from viirya/improve-sql-usertype.

3 files changed, 135 insertions, 4 deletions

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/ScalaReflection.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/ScalaReflection.scala
index be67605c45..be0d75a830 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/ScalaReflection.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/ScalaReflection.scala
@@ -17,6 +17,7 @@
 
 package org.apache.spark.sql.catalyst
 
+import org.apache.spark.SparkException
 import org.apache.spark.sql.catalyst.analysis.{UnresolvedAttribute, UnresolvedExtractValue}
 import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.catalyst.util.{ArrayBasedMapData, DateTimeUtils, GenericArrayData}
@@ -389,6 +390,15 @@ object ScalaReflection extends ScalaReflection {
           Nil,
           dataType = ObjectType(udt.userClass.getAnnotation(classOf[SQLUserDefinedType]).udt()))
         Invoke(obj, "deserialize", ObjectType(udt.userClass), getPath :: Nil)
+
+      case t if UDTRegistration.exists(getClassNameFromType(t)) =>
+        val udt = UDTRegistration.getUDTFor(getClassNameFromType(t)).get.newInstance()
+          .asInstanceOf[UserDefinedType[_]]
+        val obj = NewInstance(
+          udt.getClass,
+          Nil,
+          dataType = ObjectType(udt.getClass))
+        Invoke(obj, "deserialize", ObjectType(udt.userClass), getPath :: Nil)
     }
   }
 
@@ -603,6 +613,15 @@ object ScalaReflection extends ScalaReflection {
             dataType = ObjectType(udt.userClass.getAnnotation(classOf[SQLUserDefinedType]).udt()))
           Invoke(obj, "serialize", udt.sqlType, inputObject :: Nil)
 
+        case t if UDTRegistration.exists(getClassNameFromType(t)) =>
+          val udt = UDTRegistration.getUDTFor(getClassNameFromType(t)).get.newInstance()
+            .asInstanceOf[UserDefinedType[_]]
+          val obj = NewInstance(
+            udt.getClass,
+            Nil,
+            dataType = ObjectType(udt.getClass))
+          Invoke(obj, "serialize", udt.sqlType, inputObject :: Nil)
+
         case other =>
           throw new UnsupportedOperationException(
             s"No Encoder found for $tpe\n" + walkedTypePath.mkString("\n"))
@@ -671,6 +690,10 @@ object ScalaReflection extends ScalaReflection {
       case t if t.typeSymbol.annotations.exists(_.tpe =:= typeOf[SQLUserDefinedType]) =>
         val udt = getClassFromType(t).getAnnotation(classOf[SQLUserDefinedType]).udt().newInstance()
         Schema(udt, nullable = true)
+      case t if UDTRegistration.exists(getClassNameFromType(t)) =>
+        val udt = UDTRegistration.getUDTFor(getClassNameFromType(t)).get.newInstance()
+          .asInstanceOf[UserDefinedType[_]]
+        Schema(udt, nullable = true)
       case t if t <:< localTypeOf[Option[_]] =>
         val TypeRef(_, _, Seq(optType)) = t
         Schema(schemaFor(optType).dataType, nullable = true)
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/encoders/RowEncoder.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/encoders/RowEncoder.scala
index a8397aa5e5..44e135cbf8 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/encoders/RowEncoder.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/encoders/RowEncoder.scala
@@ -20,6 +20,7 @@ package org.apache.spark.sql.catalyst.encoders
 import scala.collection.Map
 import scala.reflect.ClassTag
 
+import org.apache.spark.SparkException
 import org.apache.spark.sql.Row
 import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.catalyst.util.{ArrayBasedMapData, DateTimeUtils, GenericArrayData}
@@ -55,10 +56,19 @@ object RowEncoder {
     case p: PythonUserDefinedType => serializerFor(inputObject, p.sqlType)
 
     case udt: UserDefinedType[_] =>
+      val annotation = udt.userClass.getAnnotation(classOf[SQLUserDefinedType])
+      val udtClass: Class[_] = if (annotation != null) {
+        annotation.udt()
+      } else {
+        UDTRegistration.getUDTFor(udt.userClass.getName).getOrElse {
+          throw new SparkException(s"${udt.userClass.getName} is not annotated with " +
+            "SQLUserDefinedType nor registered with UDTRegistration.}")
+        }
+      }
       val obj = NewInstance(
-        udt.userClass.getAnnotation(classOf[SQLUserDefinedType]).udt(),
+        udtClass,
         Nil,
-        dataType = ObjectType(udt.userClass.getAnnotation(classOf[SQLUserDefinedType]).udt()))
+        dataType = ObjectType(udtClass), false)
       Invoke(obj, "serialize", udt.sqlType, inputObject :: Nil)
 
     case TimestampType =>
@@ -187,10 +197,19 @@ object RowEncoder {
          FloatType | DoubleType | BinaryType | CalendarIntervalType => input
 
     case udt: UserDefinedType[_] =>
+      val annotation = udt.userClass.getAnnotation(classOf[SQLUserDefinedType])
+      val udtClass: Class[_] = if (annotation != null) {
+        annotation.udt()
+      } else {
+        UDTRegistration.getUDTFor(udt.userClass.getName).getOrElse {
+          throw new SparkException(s"${udt.userClass.getName} is not annotated with " +
+            "SQLUserDefinedType nor registered with UDTRegistration.}")
+        }
+      }
       val obj = NewInstance(
-        udt.userClass.getAnnotation(classOf[SQLUserDefinedType]).udt(),
+        udtClass,
         Nil,
-        dataType = ObjectType(udt.userClass.getAnnotation(classOf[SQLUserDefinedType]).udt()))
+        dataType = ObjectType(udtClass))
       Invoke(obj, "deserialize", ObjectType(udt.userClass), input :: Nil)
 
     case TimestampType =>
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/types/UDTRegistration.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/types/UDTRegistration.scala
new file mode 100644
index 0000000000..0f24e51ed2
--- /dev/null
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/types/UDTRegistration.scala
@@ -0,0 +1,89 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.sql.types
+
+import scala.collection.mutable
+
+import org.apache.spark.SparkException
+import org.apache.spark.internal.Logging
+import org.apache.spark.util.Utils
+
+/**
+ * This object keeps the mappings between user classes and their User Defined Types (UDTs).
+ * Previously we use the annotation `SQLUserDefinedType` to register UDTs for user classes.
+ * However, by doing this, we add SparkSQL dependency on user classes. This object provides
+ * alterntive approach to register UDTs for user classes.
+ */
+private[spark]
+object UDTRegistration extends Serializable with Logging {
+
+  /** The mapping between the Class between UserDefinedType and user classes. */
+  private lazy val udtMap: mutable.Map[String, String] = mutable.Map(
+    ("org.apache.spark.ml.linalg.Vector", "org.apache.spark.ml.linalg.VectorUDT"),
+    ("org.apache.spark.ml.linalg.DenseVector", "org.apache.spark.ml.linalg.VectorUDT"),
+    ("org.apache.spark.ml.linalg.SparseVector", "org.apache.spark.ml.linalg.VectorUDT"),
+    ("org.apache.spark.ml.linalg.Matrix", "org.apache.spark.ml.linalg.MatrixUDT"),
+    ("org.apache.spark.ml.linalg.DenseMatrix", "org.apache.spark.ml.linalg.MatrixUDT"),
+    ("org.apache.spark.ml.linalg.SparseMatrix", "org.apache.spark.ml.linalg.MatrixUDT"))
+
+  /**
+   * Queries if a given user class is already registered or not.
+   * @param userClassName the name of user class
+   * @return boolean value indicates if the given user class is registered or not
+   */
+  def exists(userClassName: String): Boolean = udtMap.contains(userClassName)
+
+  /**
+   * Registers an UserDefinedType to an user class. If the user class is already registered
+   * with another UserDefinedType, warning log message will be shown.
+   * @param userClass the name of user class
+   * @param udtClass the name of UserDefinedType class for the given userClass
+   */
+  def register(userClass: String, udtClass: String): Unit = {
+    if (udtMap.contains(userClass)) {
+      logWarning(s"Cannot register UDT for ${userClass}, which is already registered.")
+    } else {
+      // When register UDT with class name, we can't check if the UDT class is an UserDefinedType,
+      // or not. The check is deferred.
+      udtMap += ((userClass, udtClass))
+    }
+  }
+
+  /**
+   * Returns the Class of UserDefinedType for the name of a given user class.
+   * @param userClass class name of user class
+   * @return Option value of the Class object of UserDefinedType
+   */
+  def getUDTFor(userClass: String): Option[Class[_]] = {
+    udtMap.get(userClass).map { udtClassName =>
+      if (Utils.classIsLoadable(udtClassName)) {
+        val udtClass = Utils.classForName(udtClassName)
+        if (classOf[UserDefinedType[_]].isAssignableFrom(udtClass)) {
+          udtClass
+        } else {
+          throw new SparkException(
+            s"${udtClass.getName} is not an UserDefinedType. Please make sure registering " +
+              s"an UserDefinedType for ${userClass}")
+        }
+      } else {
+        throw new SparkException(
+          s"Can not load in UserDefinedType ${udtClassName} for user class ${userClass}.")
+      }
+    }
+  }
+}