Part1: MDEV-20837 Add MariaDB_FUNCTION_PLUGIN

- Defining MariaDB_FUNCTION_PLUGIN
- Changing the code in /plugins/type_inet/ and /plugins/type_test/
  to use MariaDB_FUNCTION_PLUGIN instead of MariaDB_FUNCTION_COLLECTION_PLUGIN.
- Changing maturity for the INET6 data type plugin from experimental to alpha.

2 files changed, 29 insertions, 0 deletions

diff --git a/sql/item_create.cc b/sql/item_create.cc
index e8eb76dfc12..246850d9548 100644
--- a/sql/item_create.cc
+++ b/sql/item_create.cc
@@ -35,6 +35,7 @@
 #include "sp.h"
 #include "sql_time.h"
 #include "sql_type_geom.h"
+#include <mysql/plugin_function.h>
 #include <mysql/plugin_function_collection.h>
 
 
@@ -5710,6 +5711,24 @@ void item_create_cleanup()
   DBUG_VOID_RETURN;
 }
 
+
+static Create_func *
+function_plugin_find_native_function_builder(THD *thd, const LEX_CSTRING &name)
+{
+  plugin_ref plugin;
+  if ((plugin= my_plugin_lock_by_name(thd, &name, MariaDB_FUNCTION_PLUGIN)))
+  {
+    Create_func *builder=
+      reinterpret_cast<Plugin_function*>(plugin_decl(plugin)->info)->
+        create_func();
+    // TODO: MDEV-20846 Add proper unlocking for MariaDB_FUNCTION_PLUGIN
+    plugin_unlock(thd, plugin);
+    return builder;
+  }
+  return NULL;
+}
+
+
 Create_func *
 find_native_function_builder(THD *thd, const LEX_CSTRING *name)
 {
@@ -5724,6 +5743,9 @@ find_native_function_builder(THD *thd, const LEX_CSTRING *name)
   if (func && (builder= func->builder))
     return builder;
 
+  if ((builder= function_plugin_find_native_function_builder(thd, *name)))
+    return builder;
+
   if ((builder= Plugin_find_native_func_builder_param(*name).find(thd)))
     return builder;
 
diff --git a/sql/sql_plugin.cc b/sql/sql_plugin.cc
index b108dfcd11f..2beb9fa0267 100644
--- a/sql/sql_plugin.cc
+++ b/sql/sql_plugin.cc
@@ -39,6 +39,7 @@
 #include <mysql/plugin_password_validation.h>
 #include <mysql/plugin_encryption.h>
 #include <mysql/plugin_data_type.h>
+#include <mysql/plugin_function.h>
 #include <mysql/plugin_function_collection.h>
 #include "sql_plugin_compat.h"
 
@@ -94,6 +95,7 @@ const LEX_CSTRING plugin_type_names[MYSQL_MAX_PLUGIN_TYPE_NUM]=
   { STRING_WITH_LEN("PASSWORD VALIDATION") },
   { STRING_WITH_LEN("ENCRYPTION") },
   { STRING_WITH_LEN("DATA TYPE") },
+  { STRING_WITH_LEN("FUNCTION") },
   { STRING_WITH_LEN("FUNCTION COLLECTION") }
 };
 
@@ -115,6 +117,7 @@ plugin_type_init plugin_type_initialize[MYSQL_MAX_PLUGIN_TYPE_NUM]=
 {
   0, ha_initialize_handlerton, 0, 0,initialize_schema_table,
   initialize_audit_plugin, 0, 0, 0, initialize_encryption_plugin, 0,
+  0, // FUNCTION
   Plugin_function_collection::init_plugin
 };
 
@@ -122,6 +125,7 @@ plugin_type_init plugin_type_deinitialize[MYSQL_MAX_PLUGIN_TYPE_NUM]=
 {
   0, ha_finalize_handlerton, 0, 0, finalize_schema_table,
   finalize_audit_plugin, 0, 0, 0, finalize_encryption_plugin, 0,
+  0, // FUNCTION
   Plugin_function_collection::deinit_plugin
 };
 
@@ -135,6 +139,7 @@ static int plugin_type_initialization_order[MYSQL_MAX_PLUGIN_TYPE_NUM]=
   MYSQL_DAEMON_PLUGIN,
   MariaDB_ENCRYPTION_PLUGIN,
   MariaDB_DATA_TYPE_PLUGIN,
+  MariaDB_FUNCTION_PLUGIN,
   MariaDB_FUNCTION_COLLECTION_PLUGIN,
   MYSQL_STORAGE_ENGINE_PLUGIN,
   MYSQL_INFORMATION_SCHEMA_PLUGIN,
@@ -179,6 +184,7 @@ static int min_plugin_info_interface_version[MYSQL_MAX_PLUGIN_TYPE_NUM]=
   MariaDB_PASSWORD_VALIDATION_INTERFACE_VERSION,
   MariaDB_ENCRYPTION_INTERFACE_VERSION,
   MariaDB_DATA_TYPE_INTERFACE_VERSION,
+  MariaDB_FUNCTION_INTERFACE_VERSION,
   MariaDB_FUNCTION_COLLECTION_INTERFACE_VERSION
 };
 static int cur_plugin_info_interface_version[MYSQL_MAX_PLUGIN_TYPE_NUM]=
@@ -194,6 +200,7 @@ static int cur_plugin_info_interface_version[MYSQL_MAX_PLUGIN_TYPE_NUM]=
   MariaDB_PASSWORD_VALIDATION_INTERFACE_VERSION,
   MariaDB_ENCRYPTION_INTERFACE_VERSION,
   MariaDB_DATA_TYPE_INTERFACE_VERSION,
+  MariaDB_FUNCTION_INTERFACE_VERSION,
   MariaDB_FUNCTION_COLLECTION_INTERFACE_VERSION
 };