/* 
  Copyright (C) 2013 Kentoku Shiba
  2013/08/26 - New columns by Roberto Spadim

  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 1
#include "mysql_version.h"
#include "mysql/plugin.h"
#include "sql_class.h"
#include "sql_show.h"

static I_List<THD> *metadata_lock_info_threads;

static ST_FIELD_INFO i_s_metadata_lock_info_fields_info[] =
{
  {"THREAD_ID", 20, MYSQL_TYPE_LONGLONG, 0, MY_I_S_UNSIGNED, "thread_id", SKIP_OPEN_TABLE},
  {"QUERY_ID", 20, MYSQL_TYPE_LONGLONG, 0, MY_I_S_UNSIGNED, "query_id", SKIP_OPEN_TABLE},
  {"LOCK_DURATION", 12, MYSQL_TYPE_STRING, 0, 0, "lock_duration", SKIP_OPEN_TABLE},
  {"LOCK_MODE", 24, MYSQL_TYPE_STRING, 0, 0, "lock_mode", SKIP_OPEN_TABLE},
  {"LOCK_NAMESPACE", 30, MYSQL_TYPE_STRING, 0, 0, "lock_namespace", SKIP_OPEN_TABLE},
  {"KEY", 64, MYSQL_TYPE_STRING, 0, 0, "key", SKIP_OPEN_TABLE},
  {"SUB_KEY", 64, MYSQL_TYPE_STRING, 0, 0, "sub_key", SKIP_OPEN_TABLE},
  {NULL, 0,  MYSQL_TYPE_STRING, 0, 0, NULL, 0}
};

static int i_s_metadata_lock_info_fill_table(
  THD *thd,
  TABLE_LIST *tables,
  COND *cond
) {
  TABLE *table = tables->table;
  DBUG_ENTER("i_s_metadata_lock_info_fill_table");
  mysql_mutex_lock(&LOCK_thread_count);

  if (!thd->killed)
  {
    I_List_iterator<THD> thread_it(*metadata_lock_info_threads);
    THD* tmp_thd;
    while ((tmp_thd = thread_it++))
    {
      table->field[0]->store((longlong) tmp_thd->thread_id, TRUE);
      table->field[1]->store((longlong) tmp_thd->query_id, TRUE);
      MDL_context *mdl_context = &tmp_thd->mdl_context;
      uint duration;
      for (duration = MDL_STATEMENT; duration < MDL_DURATION_END; ++duration)
      {
        if(duration==MDL_STATEMENT)
	  table->field[2]->store("Statement", 9, system_charset_info);
	else if(duration==MDL_TRANSACTION)
	  table->field[2]->store("Transaction", 11, system_charset_info);
	else if(duration==MDL_EXPLICIT)
	  table->field[2]->store("Explicit", 8, system_charset_info);
	else if(duration==MDL_DURATION_END)
	  table->field[2]->store("Duration END", 12, system_charset_info);
	else
	  table->field[2]->store("Unknown", 7, system_charset_info);
	
        MDL_ticket *mdl_ticket;
        MDL_context::Ticket_iterator ticket_it(
          mdl_context->m_tickets[duration]);
        while ((mdl_ticket = ticket_it++))
        {
          if(mdl_ticket->get_type()==MDL_INTENTION_EXCLUSIVE)
            table->field[3]->store("MDL_INTENTION_EXCLUSIVE", 23, system_charset_info);
	  else if(mdl_ticket->get_type()==MDL_SHARED)
            table->field[3]->store("MDL_SHARED", 10, system_charset_info);
	  else if(mdl_ticket->get_type()==MDL_SHARED_HIGH_PRIO)
            table->field[3]->store("MDL_SHARED_HIGH_PRIO", 20, system_charset_info);
	  else if(mdl_ticket->get_type()==MDL_SHARED_READ)
            table->field[3]->store("MDL_SHARED_READ", 15, system_charset_info);
	  else if(mdl_ticket->get_type()==MDL_SHARED_WRITE)
            table->field[3]->store("MDL_SHARED_WRITE", 16, system_charset_info);
	  else if(mdl_ticket->get_type()==MDL_SHARED_UPGRADABLE)
            table->field[3]->store("MDL_SHARED_UPGRADABLE", 21, system_charset_info);
	  else if(mdl_ticket->get_type()==MDL_SHARED_NO_WRITE)
            table->field[3]->store("MDL_SHARED_NO_WRITE", 19, system_charset_info);
	  else if(mdl_ticket->get_type()==MDL_SHARED_NO_READ_WRITE)
            table->field[3]->store("MDL_SHARED_NO_READ_WRITE", 24, system_charset_info);
	  else if(mdl_ticket->get_type()==MDL_EXCLUSIVE)
            table->field[3]->store("MDL_EXCLUSIVE", 13, system_charset_info);
	  else if(mdl_ticket->get_type()==MDL_TYPE_END)
            table->field[3]->store("MDL_TYPE_END", 12, system_charset_info);
	  else
            table->field[3]->store("Unkown", 6, system_charset_info);
	    
	  MDL_key *mdl_key = mdl_ticket->get_key();
	  if(mdl_key->mdl_namespace()==MDL_key::GLOBAL)
	    table->field[4]->store("Global read lock", 16, system_charset_info);
	  else if(mdl_key->mdl_namespace()==MDL_key::SCHEMA)
	    table->field[4]->store("Schema metadata lock", 20, system_charset_info);
	  else if(mdl_key->mdl_namespace()==MDL_key::TABLE)
	    table->field[4]->store("Table metadata lock", 19, system_charset_info);
	  else if(mdl_key->mdl_namespace()==MDL_key::FUNCTION)
	    table->field[4]->store("Stored function metadata lock", 29, system_charset_info);
	  else if(mdl_key->mdl_namespace()==MDL_key::PROCEDURE)
	    table->field[4]->store("Stored procedure metadata lock", 30, system_charset_info);
	  else if(mdl_key->mdl_namespace()==MDL_key::TRIGGER)
	    table->field[4]->store("Trigger metadata lock", 21, system_charset_info);
	  else if(mdl_key->mdl_namespace()==MDL_key::EVENT)
	    table->field[4]->store("Event metadata lock", 19, system_charset_info);
	  else if(mdl_key->mdl_namespace()==MDL_key::COMMIT)
	    table->field[4]->store("Commit metadata lock", 20, system_charset_info);
	  else if(mdl_key->mdl_namespace()==MDL_key::USER_LOCK)
	    table->field[4]->store("User lock", 9, system_charset_info);
	  else if(mdl_key->mdl_namespace()==MDL_key::NAMESPACE_END)
	    table->field[4]->store("NAMESPACE_END", 13, system_charset_info);
	  else
	    table->field[4]->store("Unknown", 7, system_charset_info);

          table->field[5]->store(mdl_key->db_name(),
            mdl_key->db_name_length(), system_charset_info);
          table->field[6]->store(mdl_key->name(),
            mdl_key->name_length(), system_charset_info);
          if (schema_table_store_record(thd, table))
          {
            mysql_mutex_unlock(&LOCK_thread_count);
            DBUG_RETURN(1);
          }
        }
      }
    }
  }
  mysql_mutex_unlock(&LOCK_thread_count);
  DBUG_RETURN(0);
}

static int i_s_metadata_lock_info_init(
  void *p
) {
  ST_SCHEMA_TABLE *schema = (ST_SCHEMA_TABLE *) p;
  DBUG_ENTER("i_s_metadata_lock_info_init");
  schema->fields_info = i_s_metadata_lock_info_fields_info;
  schema->fill_table = i_s_metadata_lock_info_fill_table;
  schema->idx_field1 = 0;
#ifdef _WIN32
  HMODULE current_module = GetModuleHandle(NULL);
  metadata_lock_info_threads =
    (I_List<THD> *) GetProcAddress(current_module,
      "?threads@@3V?$I_List@VTHD@@@@A");
#else
  metadata_lock_info_threads = &threads;
#endif
  DBUG_RETURN(0);
}

static int i_s_metadata_lock_info_deinit(
  void *p
) {
  DBUG_ENTER("i_s_metadata_lock_info_deinit");
  DBUG_RETURN(0);
}

static struct st_mysql_information_schema i_s_metadata_lock_info_plugin =
{ MYSQL_INFORMATION_SCHEMA_INTERFACE_VERSION };

#ifdef MARIADB_BASE_VERSION
maria_declare_plugin(metadata_lock_info)
{
  MYSQL_INFORMATION_SCHEMA_PLUGIN,
  &i_s_metadata_lock_info_plugin,
  "METADATA_LOCK_INFO",
  "Kentoku Shiba",
  "Metadata locking viewer",
  PLUGIN_LICENSE_GPL,
  i_s_metadata_lock_info_init,
  i_s_metadata_lock_info_deinit,
  0x0001,
  NULL,
  NULL,
  NULL,
  MariaDB_PLUGIN_MATURITY_ALPHA,
}
maria_declare_plugin_end;
#else
mysql_declare_plugin(metadata_lock_info)
{
  MYSQL_INFORMATION_SCHEMA_PLUGIN,
  &i_s_metadata_lock_info_plugin,
  "METADATA_LOCK_INFO",
  "Kentoku Shiba",
  "Metadata locking viewer",
  PLUGIN_LICENSE_GPL,
  i_s_metadata_lock_info_init,
  i_s_metadata_lock_info_deinit,
  0x0001,
  NULL,
  NULL,
  NULL,
#if MYSQL_VERSION_ID >= 50600
  0,
#endif
}
mysql_declare_plugin_end;
#endif