mariadb/plugin
Alexander Barkov f11504af51 MDEV-20034 Add support for the pre-defined weak SYS_REFCURSOR
This patch adds support for SYS_REFCURSOR (a weakly typed cursor)
for both sql_mode=ORACLE and sql_mode=DEFAULT.

Works as a regular stored routine variable, parameter and return value:

- can be passed as an IN parameter to stored functions and procedures
- can be passed as an INOUT and OUT parameter to stored procedures
- can be returned from a stored function

Note, strongly typed REF CURSOR will be added separately.

Note, to maintain dependencies easier, some parts of sql_class.h
and item.h were moved to new header files:

- select_results.h:
  class select_result_sink
  class select_result
  class select_result_interceptor

- sp_cursor.h:
  class sp_cursor_statistics
  class sp_cursor

- sp_rcontext_handler.h
  class Sp_rcontext_handler and its descendants

The implementation consists of the following parts:
- A new class sp_cursor_array deriving from Dynamic_array

- A new class Statement_rcontext which contains data shared
  between sub-statements of a compound statement.
  It has a member m_statement_cursors of the sp_cursor_array data type,
  as well as open cursor counter. THD inherits from Statement_rcontext.

- A new data type handler Type_handler_sys_refcursor in plugins/type_cursor/
  It is designed to store uint16 references -
  positions of the cursor in THD::m_statement_cursors.

- Type_handler_sys_refcursor suppresses some derived numeric features.
  When a SYS_REFCURSOR variable is used as an integer an error is raised.

- A new abstract class sp_instr_fetch_cursor. It's needed to share
  the common code between "OPEN cur" (for static cursors) and
  "OPER cur FOR stmt" (for SYS_REFCURSORs).

- New sp_instr classes:
  * sp_instr_copen_by_ref      - OPEN sys_ref_curor FOR stmt;
  * sp_instr_cfetch_by_ref     - FETCH sys_ref_cursor INTO targets;
  * sp_instr_cclose_by_ref     - CLOSE sys_ref_cursor;
  * sp_instr_destruct_variable - to destruct SYS_REFCURSOR variables when
                                 the execution goes out of the BEGIN..END block
                                 where SYS_REFCURSOR variables are declared.
- New methods in LEX:
  * sp_open_cursor_for_stmt   - handles "OPEN sys_ref_cursor FOR stmt".
  * sp_add_instr_fetch_cursor - "FETCH cur INTO targets" for both
                                static cursors and SYS_REFCURSORs.
  * sp_close - handles "CLOSE cur" both for static cursors and SYS_REFCURSORs.

- Changes in cursor functions to handle both static cursors and SYS_REFCURSORs:
  * Item_func_cursor_isopen
  * Item_func_cursor_found
  * Item_func_cursor_notfound
  * Item_func_cursor_rowcount

- A new system variable @@max_open_cursors - to limit the number
  of cursors (static and SYS_REFCURSORs) opened at the same time.
  Its allowed range is [0-65536], with 50 by default.

- A new virtual method Type_handler::can_return_bool() telling
  if calling item->val_bool() is allowed for Items of this data type,
  or if otherwise the "Illegal parameter for operation" error should be raised
  at fix_fields() time.

- New methods in Sp_rcontext_handler:
  * get_cursor()
  * get_cursor_by_ref()

- A new class Sp_rcontext_handler_statement to handle top level statement
  wide cursors which are shared by all substatements.

- A new virtual method expr_event_handler() in classes Item and Field.
  It's needed to close (and make available for a new OPEN)
  unused THD::m_statement_cursors elements which do not have any references
  any more. It can happen in various moments in time, e.g.
  * after evaluation parameters of an SQL routine
  * after assigning a cursor expression into a SYS_REFCURSOR variable
  * when leaving a BEGIN..END block with SYS_REFCURSOR variables
  * after setting OUT/INOUT routine actual parameters from formal
    parameters.
2025-04-19 10:59:58 +04:00
..
audit_null MDEV-7389 Request: log warnings into SQL_ERROR_LOG 2023-05-24 13:21:55 +03:00
auth_dialog Merge 10.1 into 10.2 2019-05-13 17:54:04 +03:00
auth_ed25519 ed25519: support empty password 2024-11-08 07:17:54 +01:00
auth_examples MDEV-31855 validate ssl certificates using client password in the internal client 2024-02-04 22:19:19 +01:00
auth_gssapi Fix typos in C comments in miscellaneous files 2025-03-24 13:36:28 +11:00
auth_pam Tag my_printf_error with ATTRIBUTE_FORMAT 2025-02-11 20:32:55 +01:00
auth_parsec MDEV-35482 Raise the plugin PARSEC maturity 2024-12-06 20:28:46 +01:00
auth_pipe Merge 10.1 into 10.2 2019-05-13 17:54:04 +03:00
auth_socket Merge 11.4 into 11.7 2024-12-02 17:51:17 +02:00
aws_key_management cleanup: CREATE_TYPELIB_FOR() helper 2024-11-05 14:00:47 -08:00
cracklib_password_check Merge 10.6 into 10.11 2024-02-08 15:04:46 +02:00
daemon_example MDEV-34534 main.plugin_load(daemon_example) - AddressSanitizer: Joining already joined thread, aborting 2024-11-18 22:35:40 +11:00
debug_key_management Merge branch '5.5' into 10.1 2019-05-11 22:19:05 +03:00
disks Fix typos in C comments in miscellaneous files 2025-03-24 13:36:28 +11:00
example_key_management Merge branch '5.5' into 10.1 2019-05-11 22:19:05 +03:00
feedback Fix typos in C comments in miscellaneous files 2025-03-24 13:36:28 +11:00
file_key_management MDEV-9158 post-merge fixes 2025-02-11 20:31:36 +01:00
fulltext MDEV-28671 post-merge fixes 2024-05-27 12:39:02 +02:00
func_test MDEV-27277 Add a warning when max_sort_length is reached 2024-10-22 21:42:53 +07:00
handler_socket Fix typos in C comments in miscellaneous files 2025-03-24 13:36:28 +11:00
hashicorp_key_management Merge 11.4 into 11.7 2024-12-02 17:51:17 +02:00
locale_info MDEV-31340 Remove MY_COLLATION_HANDLER::strcasecmp() 2024-04-18 15:22:10 +04:00
metadata_lock_info Merge remote-tracking branch 'origin/11.2' into 11.4 2024-07-09 21:45:37 +04:00
password_reuse_check Fix typos in C comments in miscellaneous files 2025-03-24 13:36:28 +11:00
provider_bzip2 SUMMARY/DESCRIPTION for compression provider RPMs 2021-12-08 14:57:37 +01:00
provider_lz4 SUMMARY/DESCRIPTION for compression provider RPMs 2021-12-08 14:57:37 +01:00
provider_lzma SUMMARY/DESCRIPTION for compression provider RPMs 2021-12-08 14:57:37 +01:00
provider_lzo SUMMARY/DESCRIPTION for compression provider RPMs 2021-12-08 14:57:37 +01:00
provider_snappy SUMMARY/DESCRIPTION for compression provider RPMs 2021-12-08 14:57:37 +01:00
qc_info MDEV-33091 pcre2 headers aren't found on Solaris 2024-09-05 12:14:06 +10:00
query_response_time Fix typos in C comments in miscellaneous files 2025-03-24 13:36:28 +11:00
server_audit Fix typos in C comments in miscellaneous files 2025-03-24 13:36:28 +11:00
simple_password_check Merge branch '10.6' into 10.7 2022-08-08 17:12:32 +02:00
sql_errlog Tag the logger service with ATTRIBUTE_FORMAT 2025-02-12 10:17:44 +01:00
test_sql_service MDEV-28671 post-merge fixes 2024-05-27 12:39:02 +02:00
type_cursor MDEV-20034 Add support for the pre-defined weak SYS_REFCURSOR 2025-04-19 10:59:58 +04:00
type_geom MDEV-32205 crash in get_schema_key_period_usage_record without InnoDB 2024-02-12 22:26:06 +01:00
type_inet MDEV-34189 Unexpected error on WHERE inet6col 2025-01-29 09:08:19 +04:00
type_mysql_json Merge 10.6 into 10.11 2024-06-27 10:26:09 +03:00
type_mysql_timestamp MDEV-19123 Change default charset from latin1 to utf8mb4 2024-07-11 10:21:07 +04:00
type_test MDEV-19123 Change default charset from latin1 to utf8mb4 2024-07-11 10:21:07 +04:00
type_uuid Fix typos in C comments in miscellaneous files 2025-03-24 13:36:28 +11:00
user_variables Merge 10.6 into 10.11 2024-01-18 19:22:23 +02:00
userstat MDEV-34571 Add page accessed and pages read from disk to table_stats 2024-07-12 11:28:18 +03:00
versioning Merge branch '11.8' into main 2025-04-18 17:11:01 +02:00
win_auth_client Vanilla cleanups and refactorings 2021-10-26 17:07:46 +02:00
wsrep_info test.cnf files should !include default_my.cnf 2024-02-03 11:22:20 +01:00