[SPARK-20303][SQL] Rename createTempFunction to registerFunction

### What changes were proposed in this pull request?
Session catalog API `createTempFunction` is being used by Hive build-in functions, persistent functions, and temporary functions. Thus, the name is confusing. This PR is to rename it by `registerFunction`. Also we can move construction of `FunctionBuilder` and `ExpressionInfo` into the new `registerFunction`, instead of duplicating the logics everywhere.

In the next PRs, the remaining Function-related APIs also need cleanups.

### How was this patch tested?
Existing test cases.

Author: Xiao Li <gatorsmile@gmail.com>

Closes #17615 from gatorsmile/cleanupCreateTempFunction.

1 files changed, 21 insertions, 19 deletions

diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalogSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalogSuite.scala
index 9ba846fb25..be8903000a 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalogSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalogSuite.scala
@@ -1162,10 +1162,10 @@ abstract class SessionCatalogSuite extends PlanTest {
     withBasicCatalog { catalog =>
       val tempFunc1 = (e: Seq[Expression]) => e.head
       val tempFunc2 = (e: Seq[Expression]) => e.last
-      val info1 = new ExpressionInfo("tempFunc1", "temp1")
-      val info2 = new ExpressionInfo("tempFunc2", "temp2")
-      catalog.createTempFunction("temp1", info1, tempFunc1, ignoreIfExists = false)
-      catalog.createTempFunction("temp2", info2, tempFunc2, ignoreIfExists = false)
+      catalog.registerFunction(
+        newFunc("temp1", None), ignoreIfExists = false, functionBuilder = Some(tempFunc1))
+      catalog.registerFunction(
+        newFunc("temp2", None), ignoreIfExists = false, functionBuilder = Some(tempFunc2))
       val arguments = Seq(Literal(1), Literal(2), Literal(3))
       assert(catalog.lookupFunction(FunctionIdentifier("temp1"), arguments) === Literal(1))
       assert(catalog.lookupFunction(FunctionIdentifier("temp2"), arguments) === Literal(3))
@@ -1174,13 +1174,15 @@ abstract class SessionCatalogSuite extends PlanTest {
         catalog.lookupFunction(FunctionIdentifier("temp3"), arguments)
       }
       val tempFunc3 = (e: Seq[Expression]) => Literal(e.size)
-      val info3 = new ExpressionInfo("tempFunc3", "temp1")
       // Temporary function already exists
-      intercept[TempFunctionAlreadyExistsException] {
-        catalog.createTempFunction("temp1", info3, tempFunc3, ignoreIfExists = false)
-      }
+      val e = intercept[AnalysisException] {
+        catalog.registerFunction(
+          newFunc("temp1", None), ignoreIfExists = false, functionBuilder = Some(tempFunc3))
+      }.getMessage
+      assert(e.contains("Function temp1 already exists"))
       // Temporary function is overridden
-      catalog.createTempFunction("temp1", info3, tempFunc3, ignoreIfExists = true)
+      catalog.registerFunction(
+        newFunc("temp1", None), ignoreIfExists = true, functionBuilder = Some(tempFunc3))
       assert(
         catalog.lookupFunction(
           FunctionIdentifier("temp1"), arguments) === Literal(arguments.length))
@@ -1193,8 +1195,8 @@ abstract class SessionCatalogSuite extends PlanTest {
       assert(!catalog.isTemporaryFunction(FunctionIdentifier("temp1")))
 
       val tempFunc1 = (e: Seq[Expression]) => e.head
-      val info1 = new ExpressionInfo("tempFunc1", "temp1")
-      catalog.createTempFunction("temp1", info1, tempFunc1, ignoreIfExists = false)
+      catalog.registerFunction(
+        newFunc("temp1", None), ignoreIfExists = false, functionBuilder = Some(tempFunc1))
 
       // Returns true when the function is temporary
       assert(catalog.isTemporaryFunction(FunctionIdentifier("temp1")))
@@ -1243,9 +1245,9 @@ abstract class SessionCatalogSuite extends PlanTest {
 
   test("drop temp function") {
     withBasicCatalog { catalog =>
-      val info = new ExpressionInfo("tempFunc", "func1")
       val tempFunc = (e: Seq[Expression]) => e.head
-      catalog.createTempFunction("func1", info, tempFunc, ignoreIfExists = false)
+      catalog.registerFunction(
+        newFunc("func1", None), ignoreIfExists = false, functionBuilder = Some(tempFunc))
       val arguments = Seq(Literal(1), Literal(2), Literal(3))
       assert(catalog.lookupFunction(FunctionIdentifier("func1"), arguments) === Literal(1))
       catalog.dropTempFunction("func1", ignoreIfNotExists = false)
@@ -1284,9 +1286,9 @@ abstract class SessionCatalogSuite extends PlanTest {
 
   test("lookup temp function") {
     withBasicCatalog { catalog =>
-      val info1 = new ExpressionInfo("tempFunc1", "func1")
       val tempFunc1 = (e: Seq[Expression]) => e.head
-      catalog.createTempFunction("func1", info1, tempFunc1, ignoreIfExists = false)
+      catalog.registerFunction(
+        newFunc("func1", None), ignoreIfExists = false, functionBuilder = Some(tempFunc1))
       assert(catalog.lookupFunction(
         FunctionIdentifier("func1"), Seq(Literal(1), Literal(2), Literal(3))) == Literal(1))
       catalog.dropTempFunction("func1", ignoreIfNotExists = false)
@@ -1298,14 +1300,14 @@ abstract class SessionCatalogSuite extends PlanTest {
 
   test("list functions") {
     withBasicCatalog { catalog =>
-      val info1 = new ExpressionInfo("tempFunc1", "func1")
-      val info2 = new ExpressionInfo("tempFunc2", "yes_me")
+      val funcMeta1 = newFunc("func1", None)
+      val funcMeta2 = newFunc("yes_me", None)
       val tempFunc1 = (e: Seq[Expression]) => e.head
       val tempFunc2 = (e: Seq[Expression]) => e.last
       catalog.createFunction(newFunc("func2", Some("db2")), ignoreIfExists = false)
       catalog.createFunction(newFunc("not_me", Some("db2")), ignoreIfExists = false)
-      catalog.createTempFunction("func1", info1, tempFunc1, ignoreIfExists = false)
-      catalog.createTempFunction("yes_me", info2, tempFunc2, ignoreIfExists = false)
+      catalog.registerFunction(funcMeta1, ignoreIfExists = false, functionBuilder = Some(tempFunc1))
+      catalog.registerFunction(funcMeta2, ignoreIfExists = false, functionBuilder = Some(tempFunc2))
       assert(catalog.listFunctions("db1", "*").map(_._1).toSet ==
         Set(FunctionIdentifier("func1"),
           FunctionIdentifier("yes_me")))