6 files changed, 115 insertions, 413 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index e468c80..7392af9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,9 @@
 INCLUDE_DIRECTORIES(SYSTEM ${BOOST_PATCHES_DIR} ${BOOST_INCLUDE_DIR})
 
-MYSQL_ADD_PLUGIN(table_sizes src/table_sizes.cc
-  MODULE_ONLY MODULE_OUTPUT_NAME "table_sizes")
+MYSQL_ADD_PLUGIN(table_sizes
+  table_sizes.cc
+  MODULE_ONLY MODULE_OUTPUT_NAME "table_sizes"
+  LINK_LIBRARIES extra::rapidjson
+  )
 
+ADD_DEFINITIONS(-DMYSQL_SERVER)
diff --git a/Makefile.am b/Makefile.am
deleted file mode 100644
index 3cb8f22..0000000
--- a/Makefile.am
+++ /dev/null
@@ -1,3 +0,0 @@
-AUTOMAKE_OPTIONS = foreign no-dependencies
-ACLOCAL_AMFLAGS = -I m4
-SUBDIRS = src
diff --git a/configure.ac b/configure.ac
deleted file mode 100644
index 48857f8..0000000
--- a/configure.ac
+++ /dev/null
@@ -1,68 +0,0 @@
-# Process this file with autoconf to produce a configure script.
-
-AC_PREREQ(2.59)
-AC_INIT(mysql-table-sizes-plugin, [dev])
-AC_CANONICAL_TARGET
-AC_CONFIG_MACRO_DIR([m4])
-
-AM_INIT_AUTOMAKE
-
-AC_CONFIG_SRCDIR([src/table_sizes.cc])
-AC_CONFIG_HEADER([src/config.h])
-
-AC_DEFUN([CHECK_DEBUG], [
-  AC_ARG_ENABLE([debug],
-    AS_HELP_STRING([--enable-debug], [turn on debugging, default: no]))
-
-  AC_MSG_CHECKING(whether to enable debugging)
-  AS_IF([test "x$enable_debug" = "xyes"],
-    [
-      CPPFLAGS="$CPPFLAGS -g -D_DEBUG"
-      AC_MSG_RESULT(yes)
-    ],
-    [
-      CPPFLAGS="$CPPFLAGS -g -O2 -DDBUG_OFF"
-      AC_MSG_RESULT(no)
-    ]
-  )
-])
-
-
-dnl Run tests using C++ compiler
-dnl AC_LANG(C++)
-
-CHECK_DEBUG
-
-#check for mysql src
-MYSQL_SRC_TEST
-MYSQL_PLUGIN_DIR_TEST
-#MYSQL_LIB_SERVICES_TEST
-AC_SUBST(MYSQL_INC)
-AC_SUBST(MYSQL_PLUGIN_DIR)
-#AC_SUBST(MYSQL_LIBSERVICES)
-
-#check for programs
-AC_PROG_CC
-AC_PROG_LIBTOOL
-AC_PROG_CXX
-AC_PROG_CPP
-
-#we can add the following flags for better error catching: -Werror
-CPPFLAGS="$CPPFLAGS -Werror"
-# From MySQL: Disable exceptions as they seams to create problems with gcc and threads.
-CXXFLAGS="$CXXFLAGS -fno-exceptions -fno-rtti"
-
-#make sure we have const
-AC_C_CONST
-AC_TYPE_SIZE_T
-
-#subst the relevant variables
-AC_SUBST(CPPFLAGS)
-AC_SUBST(CXXLAGS)
-AC_SUBST(CFLAGS)
-
-AC_CONFIG_FILES([
-  Makefile
-  src/Makefile
-])
-AC_OUTPUT
diff --git a/m4/ac_mysql.m4 b/m4/ac_mysql.m4
deleted file mode 100644
index b5a5c0c..0000000
--- a/m4/ac_mysql.m4
+++ /dev/null
@@ -1,96 +0,0 @@
-dnl ---------------------------------------------------------------------------
-dnl Macro: MYSQL_SRC_TEST
-dnl ---------------------------------------------------------------------------
-
-dir_resolve() dnl {{{
-{
-  pwd=`pwd`
-  cd "$1" 2>/dev/null || cd "${pwd}/${1}" 2>/dev/null
-  if test "$?" = "0"
-  then
-    echo `pwd -P`
-  else
-    echo "$1"
-  fi
-}
-dnl }}}
-
-AC_DEFUN([MYSQL_SRC_TEST], [
-  AC_MSG_CHECKING(for mysql source code)
-  AC_ARG_WITH(mysql,
-    [AS_HELP_STRING([--with-mysql=PATH], [MySQL src directory required to build.])],
-    [
-      ac_mysql_source_dir=`readlink -e "$withval"`
-      HEADERS="include/my_dir.h include/mysql/plugin.h include/mysql.h include/mysql_version.h include/config.h include/my_config.h"
-      for file in $HEADERS
-      do
-        if ! test -r "$ac_mysql_source_dir/$file"
-        then
-          AC_MSG_ERROR([Failed to find required header file $ac_mysql_source_dir/$file, check the path and make sure you've run './configure ..<options>.. && cd include && make' in MySQL 5.1 sources dir or 'cmake . && make' in MySQL 5.5 sources dir.])
-        fi
-      done
-      AC_DEFINE([MYSQL_SRC], [1], [Source directory for MySQL])
-      MYSQL_INC="-I$ac_mysql_source_dir/sql -I$ac_mysql_source_dir/include -I$ac_mysql_source_dir/regex -I$ac_mysql_source_dir -I$ac_mysql_source_dir/libbinlogevents/export -I$ac_mysql_source_dir/libbinlogevents/include -I$ac_mysql_source_dir/sql/auth"
-      AC_MSG_RESULT(["$ac_mysql_source_dir"])
-    ],
-    [
-      AC_MSG_ERROR(["No mysql source provided. Please specify --with-mysql=<mysql source dir>!"])
-    ]
-  )
-])
-
-dnl ---------------------------------------------------------------------------
-dnl Macro: MYSQL_PLUGIN_DIR_TEST
-dnl ---------------------------------------------------------------------------
-
-AC_DEFUN([MYSQL_PLUGIN_DIR_TEST], [
-  AC_MSG_CHECKING([for mysql plugin dir])
-  ac_mysql_plugin_dir=
-  AC_ARG_WITH([mysql-plugindir],
-    [AS_HELP_STRING([--with-mysql-plugindir=PATH], [MySQL plugin directory where plugin is to be copied to])],
-    [
-      ac_mysql_plugin_dir=`readlink -m "$withval"`
-      MYSQL_PLUGIN_DIR="$ac_mysql_plugin_dir"
-    ],
-    [
-      ac_mysql_plugin_dir="/usr/lib/mysql/plugin"
-      MYSQL_PLUGIN_DIR="$ac_mysql_plugin_dir"
-      AC_MSG_RESULT([--with-mysql-plugindir was not set. Using $ac_mysql_plugin_dir])
-    ]
-  )
-])
-
-dnl ---------------------------------------------------------------------------
-dnl Macro: MYSQL_LIB_SERVICES : 5.5 services lib to add to linker
-dnl ---------------------------------------------------------------------------
-
-dnl AC_DEFUN([MYSQL_LIB_SERVICES_TEST], [
-dnl   AC_MSG_CHECKING([for mysql libmysqlservices])
-dnl   ac_mysql_libservices=
-dnl   AC_ARG_WITH([mysql-libservices],
-dnl     [AS_HELP_STRING([--with-mysql-libservices=PATH], [MySQL libmysqlservices.a location (relevant for 5.5 only)])],
-dnl     [
-dnl       ac_mysql_libservices=`readlink -e "$withval"`
-dnl       if test -f "$ac_mysql_libservices"
-dnl       then
-dnl         MYSQL_LIBSERVICES="$ac_mysql_libservices"
-dnl         AC_MSG_RESULT([yes: Using $ac_mysql_libservices])
-dnl       else
-dnl         AC_MSG_ERROR([invalid MySQL libmysqlservices : $ac_mysql_libservices])
-dnl       fi
-dnl     ],
-dnl     [
-dnl       if test -f "$ac_mysql_source_dir/VERSION"
-dnl       then
-dnl         source "$ac_mysql_source_dir/VERSION"
-dnl         if test "$MYSQL_VERSION_MAJOR.$MYSQL_VERSION_MINOR" = "5.5"
-dnl         then
-dnl           AC_MSG_ERROR([no mysql-libservices. Required for MySQL 5.5])
-dnl         fi
-dnl       fi
-dnl       ac_mysql_libservices=""
-dnl       MYSQL_LIBSERVICES="$ac_mysql_libservices"
-dnl       AC_MSG_RESULT([--with-mysql-libservices was not set.])
-dnl     ]
-dnl   )
-dnl ])
diff --git a/src/Makefile.am b/src/Makefile.am
deleted file mode 100644
index 7965ee4..0000000
--- a/src/Makefile.am
+++ /dev/null
@@ -1,8 +0,0 @@
-INCLUDES = $(MYSQL_INC) $(DEPS_CFLAGS)
-
-pkgplugindir = $(MYSQL_PLUGIN_DIR)
-
-pkgplugin_LTLIBRARIES = table_sizes.la
-table_sizes_la_SOURCES = table_sizes.cc
-table_sizes_la_LIBADD = $(DEPS_LIBS)
-table_sizes_la_LDFLAGS = -module
diff --git a/src/table_sizes.cc b/table_sizes.cc
index 40d5090..ec8efc0 100644
--- a/src/table_sizes.cc
+++ b/table_sizes.cc
@@ -18,10 +18,9 @@
 
 #include "sql/mysqld.h"
 #include "sql/sql_base.h"
-#include "sql/sql_show.h"
 #include "sql/sql_class.h"    // THD
 #include "sql/sql_table.h"    // filename_to_tablename
-#include "sql/strfunc.h"      // make_lex_string_root
+#include "sql/strfunc.h"      // casedn
 #include "sql/sql_parse.h"    // sql_command_flags
 #include "sql/sql_lex.h"      // LEX
 #include "sql/item_func.h"    // Item_Func
@@ -156,25 +155,13 @@ struct LOOKUP_FIELD_VALUES {
   /**
     Value of a TABLE_SCHEMA clause.
     Note that this value length may exceed @c NAME_LEN.
-    @sa wild_db_value
   */
   boost::optional<dd::String_type> db_value;
   /**
     Value of a TABLE_NAME clause.
     Note that this value length may exceed @c NAME_LEN.
-    @sa wild_table_value
   */
   boost::optional<dd::String_type> table_value;
-  /**
-    True when @c db_value is a LIKE clause,
-    false when @c db_value is an '=' clause.
-  */
-  bool wild_db_value = {false};
-  /**
-    True when @c table_value is a LIKE clause,
-    false when @c table_value is an '=' clause.
-  */
-  bool wild_table_value = {false};
 };
 
 /**
@@ -195,19 +182,11 @@ struct LOOKUP_FIELD_VALUES {
     1             error, there can be no matching records for the condition
 */
 
-static bool get_lookup_value(Item_func *item_func, TABLE_LIST *table,
+static bool get_lookup_value(Item_func *item_func, Table_ref *table,
     LOOKUP_FIELD_VALUES *lookup_field_vals)
 {
   ST_SCHEMA_TABLE *schema_table = table->schema_table;
   ST_FIELD_INFO *field_info = schema_table->fields_info;
-  const char *field_name1 =
-      schema_table->idx_field1 >= 0
-          ? field_info[schema_table->idx_field1].field_name
-          : "";
-  const char *field_name2 =
-      schema_table->idx_field2 >= 0
-          ? field_info[schema_table->idx_field2].field_name
-          : "";
 
   if (item_func->functype() == Item_func::EQ_FUNC ||
       item_func->functype() == Item_func::EQUAL_FUNC) {
@@ -236,15 +215,16 @@ static bool get_lookup_value(Item_func *item_func, TABLE_LIST *table,
     if (!tmp_str) return 1;
 
     /* Lookup value is database name */
-    if (!cs->coll->strnncollsp(cs, (uchar *)field_name1, strlen(field_name1),
-                               (uchar *)item_field->field_name,
+    if (!cs->coll->strnncollsp(cs, (const uchar *)field_info[0].field_name,
+                               strlen(field_info[0].field_name),
+                               (const uchar *)item_field->field_name,
                                strlen(item_field->field_name))) {
       lookup_field_vals->db_value.emplace(tmp_str->ptr(), tmp_str->length());
     }
     /* Lookup value is table name */
-    else if (!cs->coll->strnncollsp(cs, (uchar *)field_name2,
-                                    strlen(field_name2),
-                                    (uchar *)item_field->field_name,
+    else if (!cs->coll->strnncollsp(cs, (const uchar *)field_info[1].field_name,
+                                    strlen(field_info[1].field_name),
+                                    (const uchar *)item_field->field_name,
                                     strlen(item_field->field_name))) {
       lookup_field_vals->table_value.emplace(tmp_str->ptr(), tmp_str->length());
     }
@@ -270,7 +250,7 @@ static bool get_lookup_value(Item_func *item_func, TABLE_LIST *table,
 */
 
 static bool calc_lookup_values_from_cond(Item *cond,
-    TABLE_LIST *table, LOOKUP_FIELD_VALUES *lookup_field_vals)
+    Table_ref *table, LOOKUP_FIELD_VALUES *lookup_field_vals)
 {
   if (!cond) return 0;
 
@@ -299,62 +279,32 @@ static bool calc_lookup_values_from_cond(Item *cond,
   @brief   Calculate lookup values(database name, table name)
 
   @details This function calculates lookup values(database name, table name)
-           from 'WHERE' condition or wild values (for 'SHOW' commands only)
-           from LEX struct and fill lookup_field_vals struct field
+           from 'WHERE' condition and fill lookup_field_vals struct field
            with these values.
 
-  @param[in]      thd                   thread handler
-  @param[in]      cond                  WHERE condition
-  @param[in]      tables                I_S table
-  @param[in, out] lookup_field_values   Struct which holds lookup values
+  @param[in]      cond                WHERE condition
+  @param[in]      tables              I_S table
+  @param[in, out] lookup_field_vals   Struct which holds lookup values
 
   @return
     0             success
     1             error, there can be no matching records for the condition
 */
 
-static bool get_lookup_field_values(THD *thd, Item *cond, TABLE_LIST *tables,
-    LOOKUP_FIELD_VALUES *lookup_field_values)
+static bool get_lookup_field_values(Item *cond, Table_ref *tables,
+    LOOKUP_FIELD_VALUES *lookup_field_vals)
 {
-  LEX *lex = thd->lex;
-  const char *wild = lex->wild ? lex->wild->ptr() : NullS;
-  bool rc = 0;
-
-  switch (lex->sql_command) {
-    case SQLCOM_SHOW_DATABASES:
-      if (wild) {
-        lookup_field_values->db_value = wild;
-        lookup_field_values->wild_db_value = true;
-      }
-      break;
-    case SQLCOM_SHOW_TABLES:
-    case SQLCOM_SHOW_TABLE_STATUS:
-    case SQLCOM_SHOW_TRIGGERS:
-    case SQLCOM_SHOW_EVENTS:
-      lookup_field_values->db_value = lex->select_lex->db;
-      if (wild) {
-        lookup_field_values->table_value = wild;
-        lookup_field_values->wild_table_value = true;
-      }
-      break;
-    default:
-      /*
-        The "default" is for queries over I_S.
-        All previous cases handle SHOW commands.
-      */
-      rc = calc_lookup_values_from_cond(cond, tables, lookup_field_values);
-      break;
-  }
+  bool rc = calc_lookup_values_from_cond(cond, tables, lookup_field_vals);
 
   if (lower_case_table_names && !rc) {
     /*
       We can safely do in-place upgrades here since all of the above cases
       are allocating a new memory buffer for these strings.
     */
-    if (lookup_field_values->db_value && !lookup_field_values->db_value->empty())
-      casedn(system_charset_info, *lookup_field_values->db_value);
-    if (lookup_field_values->table_value && !lookup_field_values->table_value->empty())
-      casedn(system_charset_info, *lookup_field_values->table_value);
+    if (lookup_field_vals->db_value && !lookup_field_vals->db_value->empty())
+      casedn(system_charset_info, *lookup_field_vals->db_value);
+    if (lookup_field_vals->table_value && !lookup_field_vals->table_value->empty())
+      casedn(system_charset_info, *lookup_field_vals->table_value);
   }
 
   return rc;
@@ -369,8 +319,16 @@ static bool is_special_db(const dd::String_type &db_name)
     || is_perfschema_db(db_name.c_str(), db_name.size());
 }
 
-static int
-make_db_list(THD *thd, std::vector<dd::String_type> *db_names,
+/**
+  Return either single or all schemas
+
+  @param[in]  thd                thread handler
+  @param[out] db_names           list of schemas
+  @param[in]  lookup_field_vals  Struct which holds lookup values
+
+  @return true  if error, false otherwise
+*/
+static int make_db_list(THD *thd, std::vector<dd::String_type> *db_names,
     LOOKUP_FIELD_VALUES *lookup_field_vals)
 {
   /*
@@ -405,53 +363,45 @@ make_db_list(THD *thd, std::vector<dd::String_type> *db_names,
 
 /*----------------------------------------------------------------------------*/
 
-/*
-  SYNOPSIS
-    thd                 thread handler
-    tables              put found tables and their size in this list
-    db                  database name to set in TABLE_LIST structure
-    path                path to database
-    wild                filter for found files
-
-  RETURN
-    FIND_FILES_OK       success
-    FIND_FILES_OOM      out of memory error
-    FIND_FILES_DIR      no such directory, or directory can't be read
+/**
+   Find files in a given directory.
+
+   @param thd     thread handler
+   @param tables  put found files in this list
+   @param db_name   filter for found files
+   @param wild    filter for found files
+
+   @return true  if error, false otherwise
 */
 typedef std::map<dd::String_type, size_t> Table_sizes_map;
-static find_files_result
-find_tables(THD *thd, Table_sizes_map &tables, const char *db,
-    const char *path, boost::optional<dd::String_type> &wild,
-    MEM_ROOT *tmp_mem_root)
+bool find_tables(THD *thd, Table_sizes_map &tables,
+    Table_ref &db_data, boost::optional<dd::String_type> &wild)
 {
   MY_DIR *dirp;
-  MEM_ROOT **save_mem_root_ptr = THR_MALLOC;
-  uint col_access = thd->col_access;
   DBUG_ENTER("find_files");
 
+  char path[FN_REFLEN + 1];
+  build_table_filename(path, sizeof(path) - 1, db_data.db, "", "", 0);
+
   if (!(dirp = my_dir(path, MYF(MY_WANT_STAT))))
   {
     if (my_errno() == ENOENT)
-      my_error(ER_BAD_DB_ERROR, MYF(0), db);
+      my_error(ER_BAD_DB_ERROR, MYF(0), db_data.db);
     else
     {
       char errbuf[MYSYS_STRERROR_SIZE];
       my_error(ER_CANT_READ_DIR, MYF(0), path,
           my_errno(), my_strerror(errbuf, sizeof(errbuf), my_errno()));
     }
-    DBUG_RETURN(FIND_FILES_DIR);
+    return true;
   }
 
-  if (tmp_mem_root)
-    THR_MALLOC = &tmp_mem_root;
-
   char uname[NAME_LEN + 1]; /* Unencoded name */
   dd::String_type fts_schema_name, fts_table_name; /* FTS lookup */
   std::map<dd::Object_id, dd::String_type> fts_cache;
   tables.clear();
   for (uint i = 0; i < dirp->number_off_files; i++)
   {
-
     FILEINFO *file = dirp->dir_entry + i;
     /* skip '.', '..' and temp files. */
     if ((file->name[0] == '.' &&
@@ -508,18 +458,14 @@ find_tables(THD *thd, Table_sizes_map &tables, const char *db,
         continue;
     }
 
-    /* Don't show tables where we don't have any privileges */
-    if (db && !(col_access & TABLE_ACLS))
-    {
-      TABLE_LIST table_list;
-      table_list.db = db;
-      table_list.db_length = strlen(db);
-      table_list.table_name = uname;
-      table_list.table_name_length = file_name_len;
-      table_list.grant.privilege = col_access;
-      if (check_grant(thd, TABLE_ACLS, &table_list, true, 1, true))
-        continue;
-    }
+    /*
+      Check_grant will grant access if there is any column privileges on
+      all of the tables thanks to the fourth parameter (bool show_table).
+    */
+    db_data.table_name = uname;
+    db_data.table_name_length = file_name_len;
+    if (check_grant(thd, SELECT_ACL, &db_data, true, 1, true))
+      continue;
 
     tables.emplace(uname, file->mystat->st_size);
   }
@@ -527,167 +473,94 @@ find_tables(THD *thd, Table_sizes_map &tables, const char *db,
   DBUG_PRINT("info", ("found: %ld files", tables.size()));
   my_dirend(dirp);
 
-  if (tmp_mem_root)
-    THR_MALLOC = save_mem_root_ptr;
-
-  DBUG_RETURN(FIND_FILES_OK);
+  return false;
 }
 
-static int
-make_table_list(THD *thd, Table_sizes_map &table_names, LEX *lex,
-    LOOKUP_FIELD_VALUES *lookup_field_vals, const dd::String_type &db_name,
-    MEM_ROOT *tmp_mem_root)
+static bool make_table_list(THD *thd, Table_sizes_map &table_names,
+    LOOKUP_FIELD_VALUES *lookup_field_vals, Table_ref &db_data)
 {
-  char path[FN_REFLEN + 1];
-  build_table_filename(path, sizeof(path) - 1, db_name.c_str(), "", "", 0);
-
   const dd::Schema *sch_obj = NULL;
-  if (thd->dd_client()->acquire(db_name.c_str(), &sch_obj))
+  if (thd->dd_client()->acquire(db_data.db, &sch_obj) || !sch_obj)
     return 1;
-  if (!sch_obj)
-  {
-    /*
-      Report missing database only if it is a 'SHOW' command.
-      Another thread may have dropped the database after we
-      got its name from the DD.
-    */
-    if (sql_command_flags[lex->sql_command] & CF_STATUS_COMMAND)
-    {
-      my_error(ER_BAD_DB_ERROR, MYF(0), db_name.c_str());
-      return 1;
-    }
-    return 2;
-  }
 
-  find_files_result res = find_tables(thd, table_names, db_name.c_str(), path,
-      lookup_field_vals->table_value, tmp_mem_root);
-  return (res == FIND_FILES_OK) ? 0 : 2;
+  return find_tables(thd, table_names, db_data, lookup_field_vals->table_value);
 }
 
 /*----------------------------------------------------------------------------*/
 
-static struct st_mysql_information_schema info =
-{ MYSQL_INFORMATION_SCHEMA_INTERFACE_VERSION };
-
 static ST_FIELD_INFO fields_info[] =
 {
-  {"TABLE_SCHEMA", NAME_CHAR_LEN, MYSQL_TYPE_STRING, 0, 0, 0, SKIP_OPEN_TABLE},
-  {"TABLE_NAME", NAME_CHAR_LEN, MYSQL_TYPE_STRING, 0, 0, "Name",
-    SKIP_OPEN_TABLE},
+  {"TABLE_SCHEMA", NAME_CHAR_LEN, MYSQL_TYPE_STRING, 0, 0, 0, 0},
+  {"TABLE_NAME", NAME_CHAR_LEN, MYSQL_TYPE_STRING, 0, 0, "Name", 0},
   {"TABLE_SIZE", MY_INT64_NUM_DECIMAL_DIGITS, MYSQL_TYPE_LONGLONG, 0,
-    MY_I_S_UNSIGNED, "Table_size", SKIP_OPEN_TABLE},
-  {0, 0, MYSQL_TYPE_STRING, 0, 0, 0, SKIP_OPEN_TABLE}
+    MY_I_S_UNSIGNED, "Table_size", 0},
+  {0, 0, MYSQL_TYPE_STRING, 0, 0, 0, 0}
 };
 
-static int fill_table(THD *thd, TABLE_LIST *tables, Item *cond)
+static int fill_table(THD *thd, Table_ref *tables, Item *cond)
 {
-  LEX *lex = thd->lex;
   TABLE *table = tables->table;
   LOOKUP_FIELD_VALUES lookup_field_vals;
-  Security_context *sctx = thd->security_context();
   std::vector<dd::String_type> db_names;
-  int error = 1;
 
   DBUG_ENTER("fill_table");
 
-  MEM_ROOT tmp_mem_root;
-  init_sql_alloc(key_memory_get_all_tables, &tmp_mem_root,
-      TABLE_ALLOC_BLOCK_SIZE, 0);
-
-  if (get_lookup_field_values(thd, cond, tables, &lookup_field_vals))
-  {
-    error = 0;
-    goto err;
-  }
+  if (get_lookup_field_values(cond, tables, &lookup_field_vals))
+    return 0;
 
 #define STR_OR_NIL(S) ((S) ? (S->c_str()) : "<nil>")
   DBUG_PRINT("INDEX VALUES", ("db_name='%s', table_name='%s'",
         STR_OR_NIL(lookup_field_vals.db_value),
         STR_OR_NIL(lookup_field_vals.table_value)));
 
-  if (!lookup_field_vals.wild_db_value && !lookup_field_vals.wild_table_value)
-  {
-    /*
-      if lookup value is empty string then
-      it's impossible table name or db name
-    */
-    if ((lookup_field_vals.db_value
-          && lookup_field_vals.db_value->empty())
-        || (lookup_field_vals.table_value
-          && lookup_field_vals.table_value->empty()))
-    {
-      error = 0;
-      goto err;
-    }
-  }
-
-  if (lookup_field_vals.db_value && !lookup_field_vals.db_value->empty()
-      && !lookup_field_vals.wild_db_value)
-    tables->has_db_lookup_value = true;
-  if (lookup_field_vals.table_value && !lookup_field_vals.table_value->empty()
-      && !lookup_field_vals.wild_table_value)
-    tables->has_table_lookup_value = true;
-
-  if (lex->is_explain())
-  {
-    /* EXPLAIN SELECT */
-    error = 0;
-    goto err;
-  }
+  /* EXPLAIN SELECT */
+  if (thd->lex->is_explain())
+    return 0;
 
   if (make_db_list(thd, &db_names, &lookup_field_vals))
-    goto err;
+    return 1;
 
   for (auto &db_name : db_names)
   {
-    bool have_db_privileges = false;
-    if (sctx->get_active_roles()->size() > 0) {
-      LEX_CSTRING const_db_name = { db_name.c_str(), db_name.size() };
-      have_db_privileges = sctx->db_acl(const_db_name) > 0 ? true : false;
-    }
-    if (!(check_access(thd, SELECT_ACL, db_name.c_str(), &thd->col_access, NULL, 0, 1)
-          || (!thd->col_access && check_grant_db(thd, db_name.c_str())))
-        || sctx->check_access(DB_ACLS | SHOW_DB_ACL, true)
-        || have_db_privileges
-        || acl_get(thd, sctx->host().str, sctx->ip().str,
-          sctx->priv_user().str, db_name.c_str(), 0))
-    {
-      // We must make sure the schema is released and unlocked in the right
-      // order. Fail if we are unable to get a meta data lock on the schema
-      // name.
-      dd::Schema_MDL_locker mdl_handler(thd);
-      if (mdl_handler.ensure_locked(db_name.c_str()))
-        goto err;
-
-      dd::cache::Dictionary_client::Auto_releaser releaser(thd->dd_client());
-      Table_sizes_map tables;
-      int res = make_table_list(thd, tables, lex, &lookup_field_vals,
-          db_name, &tmp_mem_root);
-      if (res)
-      {
-        if (res == 2) /* Not fatal error, continue */
-          continue;
-        goto err;
-      }
+    Table_ref db_data;
+    memset(reinterpret_cast<char *>(&db_data), 0, sizeof(db_data));
+    db_data.db = db_name.c_str();
+    db_data.db_length = db_name.length();
+    db_data.grant.privilege = 0;
+
+    // Get user's global and db-level privileges.
+    if (check_access(thd, SELECT_ACL, db_data.db, &db_data.grant.privilege, NULL, false, true))
+      continue;
 
-      for (auto &table_data : tables)
-      {
-        table->field[0]->store(db_name.c_str(), db_name.size(),
-            system_charset_info);
-        table->field[1]->store(table_data.first.c_str(), table_data.first.size(),
-            system_charset_info);
-        table->field[2]->store(table_data.second, true);
-        if (schema_table_store_record(thd, table))
-          goto err;
-      }
-    }
-  }
+    // Now check, if user has access on global level or to any of database/
+    // table/column/routine.
+    if (!(db_data.grant.privilege & DB_OP_ACLS) && check_grant_db(thd, db_data.db))
+      continue;
 
-  error = 0;
+    // We must make sure the schema is released and unlocked in the right
+    // order. Fail if we are unable to get a meta data lock on the schema
+    // name.
+    dd::Schema_MDL_locker mdl_handler(thd);
+    if (mdl_handler.ensure_locked(db_data.db))
+      return 1;
 
-err:
-  free_root(&tmp_mem_root, MYF(0));
-  DBUG_RETURN(error);
+    dd::cache::Dictionary_client::Auto_releaser releaser(thd->dd_client());
+    Table_sizes_map tables_data;
+    int res = make_table_list(thd, tables_data, &lookup_field_vals, db_data);
+    if (res)
+      continue;
+
+    for (auto &table_data : tables_data)
+    {
+      table->field[0]->store(db_data.db, db_data.db_length,
+          system_charset_info);
+      table->field[1]->store(table_data.first.c_str(), table_data.first.size(),
+          system_charset_info);
+      table->field[2]->store(table_data.second, true);
+      if (schema_table_store_record(thd, table))
+        return 1;
+    }
+  }
 
   return 0;
 }
@@ -698,12 +571,12 @@ static int init(void *ptr)
 
   schema_table->fields_info = fields_info;
   schema_table->fill_table = fill_table;
-  schema_table->idx_field1 = 0;
-  schema_table->idx_field2 = 1;
-  schema_table->i_s_requested_object = OPTIMIZE_I_S_TABLE;
   return 0;
 }
 
+static struct st_mysql_information_schema info =
+{ MYSQL_INFORMATION_SCHEMA_INTERFACE_VERSION };
+
 mysql_declare_plugin(table_sizes)
 {
   MYSQL_INFORMATION_SCHEMA_PLUGIN,