-- Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.
--
-- 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

DROP FUNCTION IF EXISTS ps_thread_stack;

DELIMITER $$

CREATE DEFINER='mariadb.sys'@'localhost' FUNCTION ps_thread_stack (
        thd_id BIGINT UNSIGNED,
        debug BOOLEAN
    )
RETURNS LONGTEXT CHARSET latin1
    COMMENT '
             Description
             -----------

             Outputs a JSON formatted stack of all statements, stages and events
             within Performance Schema for the specified thread.

             Parameters
             -----------

             thd_id (BIGINT UNSIGNED):
               The id of the thread to trace. This should match the thread_id
               column from the performance_schema.threads table.
             in_verbose (BOOLEAN):
               Include file:lineno information in the events.

             Example
             -----------

             (line separation added for output)

             mysql> SELECT sys.ps_thread_stack(37, FALSE) AS thread_stack\\G
             *************************** 1. row ***************************
             thread_stack: {"rankdir": "LR","nodesep": "0.10","stack_created": "2014-02-19 13:39:03",
             "mysql_version": "5.7.3-m13","mysql_user": "root@localhost","events": 
             [{"nesting_event_id": "0", "event_id": "10", "timer_wait": 256.35, "event_info": 
             "sql/select", "wait_info": "select @@version_comment limit 1\\nerrors: 0\\nwarnings: 0\\nlock time:
             ...
            '
SQL SECURITY INVOKER
NOT DETERMINISTIC
READS SQL DATA
BEGIN

    DECLARE json_objects LONGTEXT;

    /*!50602
    -- Do not track the current thread, it will kill the stack
    UPDATE performance_schema.threads
       SET instrumented = 'NO'
     WHERE processlist_id = CONNECTION_ID();
    */

    SET SESSION group_concat_max_len=@@global.max_allowed_packet;

    -- Select the entire stack of events
    SELECT GROUP_CONCAT(CONCAT( '{'
              , CONCAT_WS( ', '
              , CONCAT('"nesting_event_id": "', IF(nesting_event_id IS NULL, '0', nesting_event_id), '"')
              , CONCAT('"event_id": "', event_id, '"')
              -- Convert from picoseconds to microseconds
              , CONCAT( '"timer_wait": ', ROUND(timer_wait/1000000, 2))  
              , CONCAT( '"event_info": "'
                  , CASE
                        WHEN event_name NOT LIKE 'wait/io%' THEN REPLACE(SUBSTRING_INDEX(event_name, '/', -2), '\\', '\\\\')
                        WHEN event_name NOT LIKE 'wait/io/file%' OR event_name NOT LIKE 'wait/io/socket%' THEN REPLACE(SUBSTRING_INDEX(event_name, '/', -4), '\\', '\\\\')
                        ELSE event_name
                    END
                  , '"'
              )
              -- Always dump the extra wait information gathered for statements
              , CONCAT( '"wait_info": "', IFNULL(wait_info, ''), '"')
              -- If debug is enabled, add the file:lineno information for waits
              , CONCAT( '"source": "', IF(true AND event_name LIKE 'wait%', IFNULL(wait_info, ''), ''), '"')
              -- Depending on the type of event, name it appropriately
              , CASE 
                     WHEN event_name LIKE 'wait/io/file%'      THEN '"event_type": "io/file"'
                     WHEN event_name LIKE 'wait/io/table%'     THEN '"event_type": "io/table"'
                     WHEN event_name LIKE 'wait/io/socket%'    THEN '"event_type": "io/socket"'
                     WHEN event_name LIKE 'wait/synch/mutex%'  THEN '"event_type": "synch/mutex"'
                     WHEN event_name LIKE 'wait/synch/cond%'   THEN '"event_type": "synch/cond"'
                     WHEN event_name LIKE 'wait/synch/rwlock%' THEN '"event_type": "synch/rwlock"'
                     WHEN event_name LIKE 'wait/lock%'         THEN '"event_type": "lock"'
                     WHEN event_name LIKE 'statement/%'        THEN '"event_type": "stmt"'
                     WHEN event_name LIKE 'stage/%'            THEN '"event_type": "stage"'
                     WHEN event_name LIKE '%idle%'             THEN '"event_type": "idle"'
                     ELSE '' 
                END                   
            )
            , '}'
          )
          ORDER BY event_id ASC SEPARATOR ',') event
    INTO json_objects
    FROM (
          /*!50600
          -- Select all statements, with the extra tracing information available
          (SELECT thread_id, event_id, event_name, timer_wait, timer_start, nesting_event_id, 
                  CONCAT(sql_text, '\\n',
                         'errors: ', errors, '\\n',
                         'warnings: ', warnings, '\\n',
                         'lock time: ', ROUND(lock_time/1000000, 2),'us\\n',
                         'rows affected: ', rows_affected, '\\n',
                         'rows sent: ', rows_sent, '\\n',
                         'rows examined: ', rows_examined, '\\n',
                         'tmp tables: ', created_tmp_tables, '\\n',
                         'tmp disk tables: ', created_tmp_disk_tables, '\\n',
                         'select scan: ', select_scan, '\\n',
                         'select full join: ', select_full_join, '\\n',
                         'select full range join: ', select_full_range_join, '\\n',
                         'select range: ', select_range, '\\n',
                         'select range check: ', select_range_check, '\\n', 
                         'sort merge passes: ', sort_merge_passes, '\\n',
                         'sort rows: ', sort_rows, '\\n',
                         'sort range: ', sort_range, '\\n',
                         'sort scan: ', sort_scan, '\\n',
                         'no index used: ', IF(no_index_used, 'TRUE', 'FALSE'), '\\n',
                         'no good index used: ', IF(no_good_index_used, 'TRUE', 'FALSE'), '\\n'
                         ) AS wait_info
             FROM performance_schema.events_statements_history_long WHERE thread_id = thd_id)
          UNION 
          -- Select all stages
          (SELECT thread_id, event_id, event_name, timer_wait, timer_start, nesting_event_id, null AS wait_info
             FROM performance_schema.events_stages_history_long WHERE thread_id = thd_id) 
          UNION */
          -- Select all events, adding information appropriate to the event
          (SELECT thread_id, event_id, 
                  CONCAT(event_name , 
                         IF(event_name NOT LIKE 'wait/synch/mutex%', IFNULL(CONCAT(' - ', operation), ''), ''), 
                         IF(number_of_bytes IS NOT NULL, CONCAT(' ', number_of_bytes, ' bytes'), ''),
                         IF(event_name LIKE 'wait/io/file%', '\\n', ''),
                         IF(object_schema IS NOT NULL, CONCAT('\\nObject: ', object_schema, '.'), ''), 
                         IF(object_name IS NOT NULL, 
                            IF (event_name LIKE 'wait/io/socket%',
                                -- Print the socket if used, else the IP:port as reported
                                CONCAT(IF (object_name LIKE ':0%', @@socket, object_name)),
                                object_name),
                            ''),
                         /*!50600 IF(index_name IS NOT NULL, CONCAT(' Index: ', index_name), ''),*/'\\n'
                         ) AS event_name,
                  timer_wait, timer_start, nesting_event_id, source AS wait_info
             FROM performance_schema.events_waits_history_long WHERE thread_id = thd_id)) events 
    ORDER BY event_id;

    RETURN CONCAT('{', 
                  CONCAT_WS(',', 
                            '"rankdir": "LR"',
                            '"nodesep": "0.10"',
                            CONCAT('"stack_created": "', NOW(), '"'),
                            CONCAT('"mysql_version": "', VERSION(), '"'),
                            CONCAT('"mysql_user": "', CURRENT_USER(), '"'),
                            CONCAT('"events": [', IFNULL(json_objects,''), ']')
                           ),
                  '}');

END$$

DELIMITER ;
