cloud-fan commented on a change in pull request #31791:
URL: https://github.com/apache/spark/pull/31791#discussion_r600755787



##########
File path: 
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/FunctionRegistry.scala
##########
@@ -707,3 +721,101 @@ object FunctionRegistry {
     (name, (info, outerBuilder))
   }
 }
+
+trait TableFunctionRegistry extends FunctionRegistryBase[LogicalPlan] {
+
+  /** Create a copy of this registry with identical functions as this 
registry. */
+  override def clone(): TableFunctionRegistry = throw new 
CloneNotSupportedException()
+}
+
+class SimpleTableFunctionRegistry
+    extends SimpleFunctionRegistryBase[LogicalPlan]
+    with TableFunctionRegistry {
+
+  override def clone(): SimpleTableFunctionRegistry = synchronized {
+    val registry = new SimpleTableFunctionRegistry
+    functionBuilders.iterator.foreach { case (name, (info, builder)) =>
+      registry.registerFunction(name, info, builder)
+    }
+    registry
+  }
+}
+
+object EmptyTableFunctionRegistry
+    extends EmptyFunctionRegistryBase[LogicalPlan]
+    with TableFunctionRegistry {
+
+  override def clone(): TableFunctionRegistry = this
+}
+
+object TableFunctionRegistry {
+
+  type TableFunctionBuilder = Seq[Expression] => LogicalPlan
+
+  private def logicalPlan[T <: LogicalPlan](name: String)
+      (implicit tag: ClassTag[T]): (String, (ExpressionInfo, 
TableFunctionBuilder)) = {
+    val constructors = tag.runtimeClass.getConstructors
+    val info = expressionInfo[T](name)
+    val builder = (expressions: Seq[Expression]) => {
+      val argTypes = expressions.map(_.dataType.typeName).mkString(", ")
+      val params = Seq.fill(expressions.size)(classOf[Expression])
+      val f = constructors.find(_.getParameterTypes.toSeq == params).getOrElse 
{
+        val validParametersCount = constructors
+          .filter(_.getParameterTypes.forall(_ == classOf[Expression]))
+          .map(_.getParameterCount).distinct.sorted
+        throw QueryCompilationErrors.invalidFunctionArgumentNumberError(
+          validParametersCount, name, params)
+      }
+      try {
+        f.newInstance(expressions : _*).asInstanceOf[LogicalPlan]
+      } catch {
+        // the exception is an invocation exception. To get a meaningful 
message, we need the
+        // cause.
+        case e: Exception =>
+          val details = if (e.getCause != null) e.getCause.getMessage else 
e.toString
+          throw QueryCompilationErrors.cannotApplyTableValuedFunctionError(
+            name, argTypes, info.getUsage, details)
+      }
+    }
+    (name, (info, builder))
+  }
+
+  /**
+   * Creates an [[ExpressionInfo]] for the function as defined by LogicalPlan T
+   * using the given name.
+   */
+  private def expressionInfo[T <: LogicalPlan : ClassTag](name: String): 
ExpressionInfo = {

Review comment:
       shall we move this to the base class?




-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

For queries about this service, please contact Infrastructure at:
us...@infra.apache.org



---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org
For additional commands, e-mail: reviews-h...@spark.apache.org

Reply via email to