MDEV-19275 Provide SQL service to plugins.

SQL service added. It provides the limited set of client library functions to be used by plugin.

Author: Alexey Botchkov

include/mysql/plugin.h

@@ -77,7 +77,7 @@ typedef struct st_mysql_xid MYSQL_XID;
 #define MYSQL_PLUGIN_INTERFACE_VERSION 0x0104
 
 /* MariaDB plugin interface version */
-#define MARIA_PLUGIN_INTERFACE_VERSION 0x010e
+#define MARIA_PLUGIN_INTERFACE_VERSION 0x010f
 
 /*
  The allowable types of plugins

include/mysql/service_sql.h

@@ -0,0 +1,99 @@
+/* Copyright (C) 2021 MariaDB Corporation
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; version 2 of the License.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1301 USA */
+
+#if defined(MYSQL_SERVER) && !defined MYSQL_SERVICE_SQL
+#define MYSQL_SERVICE_SQL
+
+#include <mysql.h>
+
+/**
+ @file
+ SQL service
+
+ Interface for plugins to execute SQL queries on the local server.
+
+ Functions of the service are the 'server-limited' client library:
+ mysql_init
+ mysql_real_connect_local
+ mysql_real_connect
+ mysql_errno
+ mysql_error
+ mysql_real_query
+ mysql_affected_rows
+ mysql_num_rows
+ mysql_store_result
+ mysql_free_result
+ mysql_fetch_row
+ mysql_close
+*/
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern struct sql_service_st {
+ MYSQL *(STDCALL *mysql_init)(MYSQL *mysql);
+ MYSQL *(*mysql_real_connect_local)(MYSQL *mysql,
+ const char *host, const char *user, const char *db,
+ unsigned long clientflag);
+ MYSQL *(STDCALL *mysql_real_connect)(MYSQL *mysql, const char *host,
+ const char *user, const char *passwd, const char *db, unsigned int port,
+ const char *unix_socket, unsigned long clientflag);
+ unsigned int(STDCALL *mysql_errno)(MYSQL *mysql);
+ const char *(STDCALL *mysql_error)(MYSQL *mysql);
+ int (STDCALL *mysql_real_query)(MYSQL *mysql, const char *q,
+ unsigned long length);
+ my_ulonglong (STDCALL *mysql_affected_rows)(MYSQL *mysql);
+ my_ulonglong (STDCALL *mysql_num_rows)(MYSQL_RES *res);
+ MYSQL_RES *(STDCALL *mysql_store_result)(MYSQL *mysql);
+ void (STDCALL *mysql_free_result)(MYSQL_RES *result);
+ MYSQL_ROW (STDCALL *mysql_fetch_row)(MYSQL_RES *result);
+ void (STDCALL *mysql_close)(MYSQL *sock);
+} *sql_service;
+
+#ifdef MYSQL_DYNAMIC_PLUGIN
+
+#define mysql_init sql_service->mysql_init
+#define mysql_real_connect_local sql_service->mysql_real_connect_local
+#define mysql_real_connect sql_service->mysql_real_connect
+#define mysql_errno(M) sql_service->mysql_errno(M)
+#define mysql_error(M) sql_service->mysql_error(M)
+#define mysql_real_query sql_service->mysql_real_query
+#define mysql_affected_rows sql_service->mysql_affected_rows
+#define mysql_num_rows sql_service->mysql_num_rows
+#define mysql_store_result sql_service->mysql_store_result
+#define mysql_free_result sql_service->mysql_free_result
+#define mysql_fetch_row sql_service->mysql_fetch_row
+#define mysql_close sql_service->mysql_close
+
+#else
+
+MYSQL *mysql_real_connect_local(MYSQL *mysql,
+ const char *host, const char *user, const char *db,
+ unsigned long clientflag);
+
+/* The rest of the function declarations mest be taken from the mysql.h */
+
+#endif /*MYSQL_DYNAMIC_PLUGIN*/
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /*MYSQL_SERVICE_SQL */
+
+

include/mysql/services.h

@@ -41,6 +41,7 @@ extern "C" {
 #include <mysql/service_thd_wait.h>
 #include <mysql/service_json.h>
 /*#include <mysql/service_wsrep.h>*/
+#include <mysql/service_sql.h>
 
 #ifdef __cplusplus
 }

include/service_versions.h

@@ -44,3 +44,4 @@
 #define VERSION_wsrep 0x0500
 #define VERSION_json 0x0100
 #define VERSION_thd_mdl 0x0100
+#define VERSION_sql_service 0x0100

include/sql_common.h

@@ -61,13 +61,13 @@ typedef struct st_mysql_methods
 MYSQL_ROW column, unsigned int field_count);
  void (*flush_use_result)(MYSQL *mysql, my_bool flush_all_results);
  int (*read_change_user_result)(MYSQL *mysql);
+ void (*on_close_free)(MYSQL *mysql);
 #if !defined(MYSQL_SERVER) || defined(EMBEDDED_LIBRARY)
  MYSQL_FIELD * (*list_fields)(MYSQL *mysql);
  my_bool (*read_prepare_result)(MYSQL *mysql, MYSQL_STMT *stmt);
  int (*stmt_execute)(MYSQL_STMT *stmt);
  int (*read_binary_rows)(MYSQL_STMT *stmt);
  int (*unbuffered_fetch)(MYSQL *mysql, char **row);
- void (*free_embedded_thd)(MYSQL *mysql);
  const char *(*read_statistics)(MYSQL *mysql);
  my_bool (*next_result)(MYSQL *mysql);
  int (*read_rows_from_cursor)(MYSQL_STMT *stmt);

libmysqld/lib_sql.cc

@@ -43,7 +43,7 @@ C_MODE_START
 extern unsigned int mysql_server_last_errno;
 extern char mysql_server_last_error[MYSQL_ERRMSG_SIZE];
 static my_bool emb_read_query_result(MYSQL *mysql);
-static void emb_free_embedded_thd(MYSQL *mysql);
+static void free_embedded_thd(MYSQL *mysql);
 static bool embedded_print_errors= 0;
 
 extern "C" void unireg_clear(int exit_code)
@@ -121,7 +121,7 @@ emb_advanced_command(MYSQL *mysql, enum enum_server_command command,
  thd->killed= NOT_KILLED;
  else
  {
- emb_free_embedded_thd(mysql);
+ free_embedded_thd(mysql);
  thd= 0;
  }
  }
@@ -430,7 +430,7 @@ int emb_unbuffered_fetch(MYSQL *mysql, char **row)
  return 0;
 }
 
-static void emb_free_embedded_thd(MYSQL *mysql)
+static void free_embedded_thd(MYSQL *mysql)
 {
  THD *thd= (THD*)mysql->thd;
  server_threads.erase(thd);
@@ -453,12 +453,23 @@ static MYSQL_RES * emb_store_result(MYSQL *mysql)
  return mysql_store_result(mysql);
 }
 
-int emb_read_change_user_result(MYSQL *mysql)
+static int emb_read_change_user_result(MYSQL *mysql)
 {
  mysql->net.read_pos= (uchar*)""; // fake an OK packet
  return mysql_errno(mysql) ? (int)packet_error : 1 /* length of the OK packet */;
 }
 
+static void emb_on_close_free(MYSQL *mysql)
+{
+ my_free(mysql->info_buffer);
+ mysql->info_buffer= 0;
+ if (mysql->thd)
+ {
+ free_embedded_thd(mysql);
+ mysql->thd= 0;
+ }
+}
+
 MYSQL_METHODS embedded_methods= 
 {
  emb_read_query_result,
@@ -468,12 +479,12 @@ MYSQL_METHODS embedded_methods=
  emb_fetch_lengths, 
  emb_flush_use_result,
  emb_read_change_user_result,
+ emb_on_close_free,
  emb_list_fields,
  emb_read_prepare_result,
  emb_stmt_execute,
  emb_read_binary_rows,
  emb_unbuffered_fetch,
- emb_free_embedded_thd,
  emb_read_statistics,
  emb_read_query_result,
  emb_read_rows_from_cursor

libservices/CMakeLists.txt

@@ -38,6 +38,7 @@ SET(MYSQLSERVICES_SOURCES
  thd_wait_service.c
  wsrep_service.c
  json_service.c
+ sql_service.c
  )
 
 ADD_CONVENIENCE_LIBRARY(mysqlservices ${MYSQLSERVICES_SOURCES})

libservices/sql_service.c

@@ -0,0 +1,19 @@
+
+/* Copyright (c) 2018, Monty Program Ab
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; version 2 of the License.
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+*/
+
+#include <service_versions.h>
+SERVICE_VERSION sql_service= (void*)VERSION_sql_service;

mysql-test/main/handlersocket.result

@@ -5,7 +5,7 @@ plugin_version	1.0
 plugin_status	ACTIVE
 plugin_type	DAEMON
 plugin_library	handlersocket.so
-plugin_library_version	1.14
+plugin_library_version	1.15
 plugin_author	higuchi dot akira at dena dot jp
 plugin_description	Direct access into InnoDB
 plugin_license	BSD

mysql-test/main/plugin.result

@@ -12,7 +12,7 @@ PLUGIN_STATUS	ACTIVE
 PLUGIN_TYPE	STORAGE ENGINE
 PLUGIN_TYPE_VERSION	#
 PLUGIN_LIBRARY	ha_example.so
-PLUGIN_LIBRARY_VERSION	1.14
+PLUGIN_LIBRARY_VERSION	1.15
 PLUGIN_AUTHOR	Brian Aker, MySQL AB
 PLUGIN_DESCRIPTION	Example storage engine
 PLUGIN_LICENSE	GPL
@@ -25,7 +25,7 @@ PLUGIN_STATUS	ACTIVE
 PLUGIN_TYPE	DAEMON
 PLUGIN_TYPE_VERSION	#
 PLUGIN_LIBRARY	ha_example.so
-PLUGIN_LIBRARY_VERSION	1.14
+PLUGIN_LIBRARY_VERSION	1.15
 PLUGIN_AUTHOR	Sergei Golubchik
 PLUGIN_DESCRIPTION	Unusable Daemon
 PLUGIN_LICENSE	GPL
@@ -64,7 +64,7 @@ PLUGIN_STATUS	DELETED
 PLUGIN_TYPE	STORAGE ENGINE
 PLUGIN_TYPE_VERSION	#
 PLUGIN_LIBRARY	ha_example.so
-PLUGIN_LIBRARY_VERSION	1.14
+PLUGIN_LIBRARY_VERSION	1.15
 PLUGIN_AUTHOR	Brian Aker, MySQL AB
 PLUGIN_DESCRIPTION	Example storage engine
 PLUGIN_LICENSE	GPL