[SPARK-23486]cache the function name from the external catalog for lookupFunctions

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/Analyzer.scala

@@ -17,6 +17,9 @@
 
 package org.apache.spark.sql.catalyst.analysis
 
+import java.util.Locale
+
+import scala.collection.mutable
 import scala.collection.mutable.ArrayBuffer
 import scala.util.Random
 
@@ -1204,16 +1207,32 @@ class Analyzer(
    * only performs simple existence check according to the function identifier to quickly identify
    * undefined functions without triggering relation resolution, which may incur potentially
    * expensive partition/schema discovery process in some cases.
-   *
+   * In order to avoid duplicate external functions lookup, the external function identifier will
+   * store in the local hash set externalFunctionNameSet.
    * @see [[ResolveFunctions]]
    * @see https://issues.apache.org/jira/browse/SPARK-19737
    */
   object LookupFunctions extends Rule[LogicalPlan] {
-    override def apply(plan: LogicalPlan): LogicalPlan = plan.transformAllExpressions {
-      case f: UnresolvedFunction if !catalog.functionExists(f.name) =>
-        withPosition(f) {
-          throw new NoSuchFunctionException(f.name.database.getOrElse("default"), f.name.funcName)
-        }
+    override def apply(plan: LogicalPlan): LogicalPlan = {
+      val externalFunctionNameSet = new mutable.HashSet[FunctionIdentifier]()
+      plan.transformAllExpressions {
+        case f: UnresolvedFunction
+          if externalFunctionNameSet.contains(normalizeFuncName(f.name)) => f
+        case f: UnresolvedFunction if catalog.isRegisteredFunction(f.name) => f
+        case f: UnresolvedFunction if catalog.isPersistentFunction(f.name) =>
+          externalFunctionNameSet.add(normalizeFuncName(f.name))
+          f
+        case f: UnresolvedFunction =>
+          withPosition(f) {
+            throw new NoSuchFunctionException(f.name.database.getOrElse(catalog.getCurrentDatabase),
+              f.name.funcName)
+          }
+      }
+    }
+
+    def normalizeFuncName(name: FunctionIdentifier): FunctionIdentifier = {
+      FunctionIdentifier(name.funcName.toLowerCase(Locale.ROOT),
+        name.database.orElse(Some(catalog.getCurrentDatabase)))
     }
   }
 

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

@@ -1193,6 +1193,22 @@ class SessionCatalog(
       !hiveFunctions.contains(name.funcName.toLowerCase(Locale.ROOT))
   }
 
+  /**
+   * Return whether this function has been registered in the function registry of the current
+   * session. If not existed, return false.
+   */
+  def isRegisteredFunction(name: FunctionIdentifier): Boolean = {
+    functionRegistry.functionExists(name)
+  }
+
+  /**
+   * Returns whether it is a persistent function. If not existed, returns false.
+   */
+  def isPersistentFunction(name: FunctionIdentifier): Boolean = {
+    val db = formatDatabaseName(name.database.getOrElse(getCurrentDatabase))
+    databaseExists(db) && externalCatalog.functionExists(db, name.funcName)
+  }
+
   protected def failFunctionLookup(name: FunctionIdentifier): Nothing = {
     throw new NoSuchFunctionException(
       db = name.database.getOrElse(getCurrentDatabase), func = name.funcName)

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/analysis/LookupFunctionsSuite.scala

@@ -0,0 +1,70 @@
+/*
+ * 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.catalyst.analysis
+
+import java.net.URI
+
+import org.apache.spark.sql.catalyst.{FunctionIdentifier, TableIdentifier}
+import org.apache.spark.sql.catalyst.catalog.{CatalogDatabase, InMemoryCatalog, SessionCatalog}
+import org.apache.spark.sql.catalyst.expressions.Alias
+import org.apache.spark.sql.catalyst.plans.PlanTest
+import org.apache.spark.sql.catalyst.plans.logical._
+import org.apache.spark.sql.internal.SQLConf
+
+class LookupFunctionsSuite extends PlanTest {
+
+  test("SPARK-23486: LookupFunctions should not check the same function name more than once") {
+    val externalCatalog = new CustomInMemoryCatalog
+    val conf = new SQLConf()
+    val catalog = new SessionCatalog(externalCatalog, FunctionRegistry.builtin, conf)
+    val analyzer = {
+      catalog.createDatabase(
+        CatalogDatabase("default", "", new URI("loc"), Map.empty),
+        ignoreIfExists = false)
+      new Analyzer(catalog, conf)
+    }
+
+    def table(ref: String): LogicalPlan = UnresolvedRelation(TableIdentifier(ref))
+    val unresolvedFunc = UnresolvedFunction("func", Seq.empty, false)
+    val plan = Project(
+      Seq(Alias(unresolvedFunc, "call1")(), Alias(unresolvedFunc, "call2")(),
+        Alias(unresolvedFunc, "call1")()),
+      table("TaBlE"))
+    analyzer.LookupFunctions.apply(plan)
+    assert(externalCatalog.getFunctionExistsCalledTimes == 1)
+
+    assert(analyzer.LookupFunctions.normalizeFuncName
+      (unresolvedFunc.name).database == Some("default"))
+    assert(catalog.isRegisteredFunction(unresolvedFunc.name) == false)
+    assert(catalog.isRegisteredFunction(FunctionIdentifier("max")) == true)
+
+  }
+}
+
+class CustomInMemoryCatalog extends InMemoryCatalog {
+
+  private var functionExistsCalledTimes: Int = 0
+
+  override def functionExists(db: String, funcName: String): Boolean = synchronized {
+    functionExistsCalledTimes = functionExistsCalledTimes + 1
+    true
+  }
+
+  def getFunctionExistsCalledTimes: Int = functionExistsCalledTimes
+
+}

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

@@ -1217,6 +1217,42 @@ abstract class SessionCatalogSuite extends AnalysisTest {
     }
   }
 
+  test("isRegisteredFunction") {
+    withBasicCatalog { catalog =>
+      // Returns false when the function does not register
+      assert(!catalog.isRegisteredFunction(FunctionIdentifier("temp1")))
+
+      // Returns true when the function does register
+      val tempFunc1 = (e: Seq[Expression]) => e.head
+      catalog.registerFunction(newFunc("iff", None), overrideIfExists = false,
+        functionBuilder = Some(tempFunc1) )
+      assert(catalog.isRegisteredFunction(FunctionIdentifier("iff")))
+
+      // Returns false when using the createFunction
+      catalog.createFunction(newFunc("sum", Some("db2")), ignoreIfExists = false)
+      assert(!catalog.isRegisteredFunction(FunctionIdentifier("sum")))
+      assert(!catalog.isRegisteredFunction(FunctionIdentifier("sum", Some("db2"))))
+    }
+  }
+
+  test("isPersistentFunction") {
+    withBasicCatalog { catalog =>
+      // Returns false when the function does not register
+      assert(!catalog.isPersistentFunction(FunctionIdentifier("temp2")))
+
+      // Returns false when the function does register
+      val tempFunc2 = (e: Seq[Expression]) => e.head
+      catalog.registerFunction(newFunc("iff", None), overrideIfExists = false,
+        functionBuilder = Some(tempFunc2))
+      assert(!catalog.isPersistentFunction(FunctionIdentifier("iff")))
+
+      // Return true when using the createFunction
+      catalog.createFunction(newFunc("sum", Some("db2")), ignoreIfExists = false)
+      assert(catalog.isPersistentFunction(FunctionIdentifier("sum", Some("db2"))))
+      assert(!catalog.isPersistentFunction(FunctionIdentifier("db2.sum")))
+    }
+  }
+
   test("drop function") {
     withBasicCatalog { catalog =>
       assert(catalog.externalCatalog.listFunctions("db2", "*").toSet == Set("func1"))

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

@@ -175,6 +175,10 @@ private[sql] class HiveSessionCatalog(
     super.functionExists(name) || hiveFunctions.contains(name.funcName)
   }
 
+  override def isPersistentFunction(name: FunctionIdentifier): Boolean = {
+    super.isPersistentFunction(name) || hiveFunctions.contains(name.funcName)
+  }
+
   /** List of functions we pass over to Hive. Note that over time this list should go to 0. */
   // We have a list of Hive built-in functions that we do not support. So, we will check
   // Hive's function registry and lazily load needed functions into our own function registry.