MDEV-7331 - information_schema.user_variables

debian/mariadb-server-10.2.files.in

@@ -19,6 +19,7 @@ usr/lib/mysql/plugin/server_audit.so
 usr/lib/mysql/plugin/simple_password_check.so
 usr/lib/mysql/plugin/sql_errlog.so
 usr/lib/mysql/plugin/wsrep_info.so
+usr/lib/mysql/plugin/user_variables.so
 usr/lib/libhsclient.so.*
 etc/apparmor.d/usr.sbin.mysqld
 usr/share/apport/package-hooks/source_mariadb-10.2.py

mysql-test/t/mysqld--help.test

@@ -31,7 +31,7 @@ perl;
               connect null-audit aria oqgraph sphinx thread-handling
               test-sql-discovery rpl-semi-sync query-cache-info
               query-response-time metadata-lock-info locales unix-socket
-              wsrep file-key-management/;
+              wsrep file-key-management user-variables/;
 
   # And substitute the content some environment variables with their
   # names:

plugin/user_variables/CMakeLists.txt

+MYSQL_ADD_PLUGIN(user_variables user_variables.cc)

plugin/user_variables/mysql-test/user_variables/basic.result

+SELECT PLUGIN_NAME, PLUGIN_VERSION, PLUGIN_STATUS, PLUGIN_TYPE, PLUGIN_AUTHOR, PLUGIN_DESCRIPTION, PLUGIN_LICENSE, LOAD_OPTION, PLUGIN_MATURITY FROM INFORMATION_SCHEMA.PLUGINS WHERE PLUGIN_NAME='user_variables';
+PLUGIN_NAME	user_variables
+PLUGIN_VERSION	1.0
+PLUGIN_STATUS	ACTIVE
+PLUGIN_TYPE	INFORMATION SCHEMA
+PLUGIN_AUTHOR	Sergey Vojtovich
+PLUGIN_DESCRIPTION	User-defined variables
+PLUGIN_LICENSE	GPL
+LOAD_OPTION	ON
+PLUGIN_MATURITY	Alpha
+SHOW CREATE TABLE INFORMATION_SCHEMA.USER_VARIABLES;
+Table	Create Table
+user_variables	CREATE TEMPORARY TABLE `user_variables` (
+  `VARIABLE_NAME` varchar(64) NOT NULL DEFAULT '',
+  `VARIABLE_VALUE` varchar(2048) DEFAULT NULL,
+  `VARIABLE_TYPE` varchar(64) NOT NULL DEFAULT '',
+  `CHARACTER_SET_NAME` varchar(32) DEFAULT NULL
+) ENGINE=MEMORY DEFAULT CHARSET=utf8
+FLUSH USER_VARIABLES;
+SELECT COUNT(*) FROM INFORMATION_SCHEMA.USER_VARIABLES;
+COUNT(*)
+0
+SET @int_var=1;
+SET @uint_var=CAST(2 AS UNSIGNED INTEGER);
+SET @str_var='Value of string variable';
+SET @utf8str_var=_utf8 'UTF8 string value';
+SET @double_var=CAST(1 AS DOUBLE);
+SET @dec_var=CAST(1 AS DECIMAL(20, 10));
+SET @time_var=CAST('2016-02-25' AS DATE);
+SET @' @#^%'='Value of variable with odd name';
+SET @''='Value of variable with empty name';
+SET @null_var=NULL;
+SELECT COUNT(*) FROM INFORMATION_SCHEMA.USER_VARIABLES;
+COUNT(*)
+10
+SELECT * FROM INFORMATION_SCHEMA.USER_VARIABLES ORDER BY VARIABLE_NAME;
+VARIABLE_NAME	VARIABLE_VALUE	VARIABLE_TYPE	CHARACTER_SET_NAME
+	Value of variable with empty name	VARCHAR	latin1
+ @#^%	Value of variable with odd name	VARCHAR	latin1
+dec_var	1.0000000000	DECIMAL	latin1
+double_var	1	DOUBLE	latin1
+int_var	1	INT	latin1
+null_var	NULL	VARCHAR	binary
+str_var	Value of string variable	VARCHAR	latin1
+time_var	2016-02-25	VARCHAR	latin1
+uint_var	2	INT UNSIGNED	latin1
+utf8str_var	UTF8 string value	VARCHAR	utf8
+SHOW USER_VARIABLES;
+Variable_name	Value
+	Value of variable with empty name
+ @#^%	Value of variable with odd name
+dec_var	1.0000000000
+double_var	1
+int_var	1
+null_var	NULL
+str_var	Value of string variable
+time_var	2016-02-25
+uint_var	2
+utf8str_var	UTF8 string value
+FLUSH USER_VARIABLES;
+SELECT COUNT(*) FROM INFORMATION_SCHEMA.USER_VARIABLES;
+COUNT(*)
+0

plugin/user_variables/mysql-test/user_variables/basic.test

+query_vertical SELECT PLUGIN_NAME, PLUGIN_VERSION, PLUGIN_STATUS, PLUGIN_TYPE, PLUGIN_AUTHOR, PLUGIN_DESCRIPTION, PLUGIN_LICENSE, LOAD_OPTION, PLUGIN_MATURITY FROM INFORMATION_SCHEMA.PLUGINS WHERE PLUGIN_NAME='user_variables';
+SHOW CREATE TABLE INFORMATION_SCHEMA.USER_VARIABLES;
+
+FLUSH USER_VARIABLES;
+SELECT COUNT(*) FROM INFORMATION_SCHEMA.USER_VARIABLES;
+
+SET @int_var=1;
+SET @uint_var=CAST(2 AS UNSIGNED INTEGER);
+SET @str_var='Value of string variable';
+SET @utf8str_var=_utf8 'UTF8 string value';
+SET @double_var=CAST(1 AS DOUBLE);
+SET @dec_var=CAST(1 AS DECIMAL(20, 10));
+SET @time_var=CAST('2016-02-25' AS DATE);
+SET @' @#^%'='Value of variable with odd name';
+SET @''='Value of variable with empty name';
+SET @null_var=NULL;
+
+SELECT COUNT(*) FROM INFORMATION_SCHEMA.USER_VARIABLES;
+SELECT * FROM INFORMATION_SCHEMA.USER_VARIABLES ORDER BY VARIABLE_NAME;
+--sorted_result
+SHOW USER_VARIABLES;
+
+FLUSH USER_VARIABLES;
+SELECT COUNT(*) FROM INFORMATION_SCHEMA.USER_VARIABLES;

plugin/user_variables/mysql-test/user_variables/suite.opt

+--plugin-load-add=$USER_VARIABLES_SO  --plugin-user-variables=ON

plugin/user_variables/mysql-test/user_variables/suite.pm

+package My::Suite::User_variables;
+
+@ISA = qw(My::Suite);
+
+return "No USER_VARIABLES plugin" unless
+  $ENV{USER_VARIABLES_SO} or
+  $::mysqld_variables{'user-variables'} eq "ON";
+
+return "Not run for embedded server" if $::opt_embedded_server;
+
+sub is_default { 1 }
+
+bless { };

plugin/user_variables/user_variables.cc

+/* Copyright (C) 2016 MariaDB Foundation and Sergey Vojtovich
+
+   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#define MYSQL_SERVER
+#include <sql_class.h>
+#include <table.h>
+#include <sql_show.h>
+
+
+static const LEX_CSTRING result_types[]=
+{
+  STRING_WITH_LEN("VARCHAR"),
+  STRING_WITH_LEN("DOUBLE"),
+  STRING_WITH_LEN("INT"),
+  STRING_WITH_LEN("<IMPOSSIBLE1>"), // ROW_RESULT
+  STRING_WITH_LEN("DECIMAL"),
+  STRING_WITH_LEN("<IMPOSSIBLE2>") // TIME_RESULT
+};
+
+
+static const LEX_CSTRING unsigned_result_types[]=
+{
+  STRING_WITH_LEN("<IMPOSSIBLE3>"), // UNSIGNED STRING_RESULT
+  STRING_WITH_LEN("DOUBLE UNSIGNED"),
+  STRING_WITH_LEN("INT UNSIGNED"),
+  STRING_WITH_LEN("<IMPOSSIBLE4>"), // UNSIGNED ROW_RESULT
+  STRING_WITH_LEN("DECIMAL UNSIGNED"),
+  STRING_WITH_LEN("<IMPOSSIBLE5>") // UNSIGNED TIME_RESULT
+};
+
+
+static ST_FIELD_INFO user_variables_fields_info[] =
+{
+  { "VARIABLE_NAME", NAME_CHAR_LEN, MYSQL_TYPE_STRING, 0, 0, "Variable_name", 0 },
+  { "VARIABLE_VALUE", 2048, MYSQL_TYPE_STRING, 0, MY_I_S_MAYBE_NULL, "Value", 0 },
+  { "VARIABLE_TYPE", NAME_CHAR_LEN, MYSQL_TYPE_STRING, 0, 0, 0, 0 },
+  { "CHARACTER_SET_NAME", MY_CS_NAME_SIZE, MYSQL_TYPE_STRING, 0,
+    MY_I_S_MAYBE_NULL, 0, 0 },
+  { 0, 0, MYSQL_TYPE_NULL, 0, 0, 0, 0 }
+};
+
+
+static int user_variables_fill(THD *thd, TABLE_LIST *tables, COND *cond)
+{
+  ulong i;
+  TABLE *table= tables->table;
+  Field **field= table->field;
+  String buff;
+  bool is_null;
+
+  for (i= 0; i < thd->user_vars.records; i++)
+  {
+    user_var_entry *var= (user_var_entry*) my_hash_element(&thd->user_vars, i);
+
+    field[0]->store(var->name.str, var->name.length, system_charset_info);
+
+    if (var->val_str(&is_null, &buff, NOT_FIXED_DEC))
+    {
+      field[1]->store(buff.ptr(), buff.length(), buff.charset());
+      field[1]->set_notnull();
+    }
+    else if (is_null)
+      field[1]->set_null();
+    else
+      return 1;
+
+    const LEX_CSTRING *tmp= var->unsigned_flag ?
+                            &unsigned_result_types[var->type] :
+                            &result_types[var->type];
+    field[2]->store(tmp->str, tmp->length, system_charset_info);
+
+    if (var->charset())
+    {
+      field[3]->store(var->charset()->csname, strlen(var->charset()->csname),
+                      system_charset_info);
+      field[3]->set_notnull();
+    }
+    else
+      field[3]->set_null();
+
+    if (schema_table_store_record(thd, table))
+      return 1;
+  }
+  return 0;
+}
+
+
+int user_variables_reset(void)
+{
+  THD *thd= current_thd;
+  if (thd)
+    my_hash_reset(&thd->user_vars);
+  return 0;
+}
+
+
+static int user_variables_init(void *p)
+{
+  ST_SCHEMA_TABLE *is= (ST_SCHEMA_TABLE *) p;
+  is->fields_info= user_variables_fields_info;
+  is->fill_table= user_variables_fill;
+  is->reset_table= user_variables_reset;
+  return 0;
+}
+
+
+static struct st_mysql_information_schema user_variables_descriptor=
+{ MYSQL_INFORMATION_SCHEMA_INTERFACE_VERSION };
+
+
+maria_declare_plugin(user_variables)
+{
+  MYSQL_INFORMATION_SCHEMA_PLUGIN,
+  &user_variables_descriptor,
+  "user_variables",
+  "Sergey Vojtovich",
+  "User-defined variables",
+  PLUGIN_LICENSE_GPL,
+  user_variables_init,
+  NULL,
+  0x0100,
+  NULL,
+  NULL,
+  "1.0",
+  MariaDB_PLUGIN_MATURITY_ALPHA
+}
+maria_declare_plugin_end;