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mariadb/sql/sql_const.h
Alexander Barkov 75142ff496 MDEV-36053 CURSOR declarations in PACKAGE BODY 
This change adds CURSOR declarations inside PACKAGE BODY.

PL/SQL mode:

  SET sql_mode=ORACLE;
  CREATE PACKAGE BODY pkg AS
    CURSOR mc0 IS SELECT c0, c1 FROM t1;
    PROCEDURE p1 AS
      rec mc0%ROWTYPE;
    BEGIN
      OPEN mc0;
      FETCH mc0 INTO rec;
      CLOSE mc0
    END;
  END;
  /

SQL/PSM mode:

  SET sql_mode=DEFAULT;
  CREATE PACKAGE BODY pkg
    mc0 CURSOR FOR SELECT c0, c1 FROM t1;
    PROCEDURE p1()
    BEGIN
      DECLARE rec ROW TYPE OF mc0;
      OPEN mc0;
      FETCH mc0 INTO rec;
      CLOSE mc0
    END;
  END;
  /

PACKAGE BODY cursors like local cursors
(declared inside a FUNCTION or a PROCEDURE) support:
  - OPEN/FETCH/CLOSE
  - FOR rec IN cur - an explicit cursor loop
  - Using a cursor row as an anchored variable data type:
    * DECLARE var cur%ROWTYPE;     -- sql_mode=ORACLE
    * DECLARE var ROW TYPE OF cur; -- sql_mode=DEFAULT

The patch details:

- Changing various class members and function/method parameters which
  store a CURSOR run-time address from "uint" to sp_rcontext_addr.
  A few classes now derive from sp_rcontext_addr instead of having
  a "uint m_cursor;" member.

  This change uses the same idea with what we did for SP variables,
  when we implemented PACKAGE BODY variables a few years ago.

- Fixing the grammar in sql_yacc.yy to allow CURSOR declarations
  inside PACKAGE BODY.

- Adding a new class sp_pcontext_top. It's used for the top level parse
  context (of an sp_head). Note, its children contexts still use the old
  class sp_pcontext.

  sp_pcontext_top context additionally to sp_pcontext has:

    const sp_head *m_sp; -- The pointer to the sp_head owning this context
    Dynamic_array<sp_pcursor> m_member_cursors; -- PACKAGE BODY wide cursors

  m_sp->m_parent->get_parse_context() is used to find the sp_pcontext
  belonging to the parent PACKAGE BODY from a sp_pcontext_top instance
  belonging to a PROCEDURE/FUNCTION sp_pcontext_top.

- Adding a new member in sp_rcontext:
    Dynamic_array<sp_cursor*> m_member_cursors;
  It's used to store run-time data of PACKAGE BODY wide cursors.

- Adding a new class sp_instr_copen2. It's used to open PACKAGE BODY cursors.
  Unlike the usual cursors, PACKAGE BODY cursors:
  * do not use the cursor stack (sp_rcontext::m_cstack)
  * do not need a preceeding sp_instr_cpush
  * do not need a following sp_instr_cpop

  All cursor information such as "sp_lex_cursor" resides inside
  sp_instr_copen2 itself (rather than inside sp_instr_cpush which is
  used to store "sp_lex_cursor" in case of sp_instr_copen).

  Note, the other cursor related instructions:
    sp_instr_cfetch
    sp_instr_cclose
    sp_instr_cursor_copy_struct
  do not need sp_instr_xxx2 counter-parts.
  Thy just use sp_rcontext_addr to address cursors.

- Adding Sp_rcontext_handler_member
  It's used to handle PACKAGE BODY members:
  cursors and variables declared in the PACKAGE BODY,
  when they are accessed from its executable initialization section:

    CREATE PACKAGE BODY pkg AS
      CURSOR mc0 IS SELECT c0, c1 FROM t1; -- A member (PACKAGE BODY cursor)
      mv0 mc0%ROWTYPE;                     -- A member (PACKAGE BODY variable)
      PROCEDURE p1 AS
      BEGIN
        -- Accessing members from here use sp_rcontext_handler_package_body
        -- (members of the parent PACKAGE BODY)
        OPEN mc0;
        FETCH mc0 INTO mv0;
        CLOSE mc0;
      END;
    BEGIN
      -- NEW:
      -- Accessing members from here use sp_rcontext_handler_member
      -- (PACKAGE BODY own members)
      OPEN mc0;
      FETCH mc0 INTO mv0;
      CLOSE mc0;
    END;
    /

  Member variables and cursor are now marked with the "MEMBER." prefix
  in the "SHOW PACKAGE BODY code" output.
  Some old MTR tests have been re-recorded accordingly.

- Adding new virtual methods into Sp_rcontext_handler:

  virtual const sp_variable *get_pvariable(const sp_pcontext *pctx,
                                           uint offset) const;

  virtual const sp_pcursor *get_pcursor(const sp_pcontext *pctx,
                                        uint offset) const;

  They're used from sp_instr::print() virtual implementations.
  They internally calculate a proper sp_pcontext using as a parameter
  the sp_pcontext pointed by sp_instr::m_ctx.

  For example, Sp_handler_package_body::get_pvariable()/get_pcursor()
  accesses to this sp_pcontext:
      m_ctx->top_context()->m_sp->m_parent->get_parse_context(),
  i.e. the parse context of the PACKAGE BODY which is the parent for
   the current package PROCEDURE of FUNCTION an sp_instr belongs to.

- Adding a new method LEX::find_cursor(). It searches for a cursor in
  this order:
  1.  Local cursors in the nearst surrounding BEGIN/END block.
  2a. A member cursor of the current PACKAGE BODY
      (used from the PACKAGE BODY initialization section)
  OR
  2b. A member cursor of the parrent PACKAGE BODY
      (used from a package PROCEDURE or a package FUNCTION)

  Adding a new method LEX::find_cursor_with_error().
  In case when a cursor is not found, it automatically
  raises the ER_SP_CURSOR_MISMATCH SQL condition into
  the diagnostics area.

- Adding a new method sp_head::add_instr_copenX().
  It creates sp_instr_copen for local cursors,
  or sp_instr_copen2 for non-local cursors.

- Adding a new abstract class sp_lex_cursor_instr.
  It's used a common parent class for a few sp_instr_xxx classes,
  including the new sp_instr_copen2.
  This change is needed to avoid code duplication.

- Adding a new protected method sp_instr::print_cmd_and_var(), to print
  an instruction using this format: "command name@offset".
  It's used from a few implementations of sp_instr_xxx::print(),
  including sp_instr_copen2::print().
  This change is also needed to avoid code duplication.

- Adding a new method sp_pcontext::frame_for_members_candidate(),
  to distinguish easier between local cursors/variables and
  PACKAGE BODY cursors/variables.

- Fixing "struct Lex_for_loop_st" to addionally store
  a const pointer to Sp_rcontext_handler, to distinguish between:
    * FOR rec IN local_cursor
    * FOR rec IN package_body_cursor
2025-07-03 13:36:06 +04:00

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/* Copyright (c) 2006, 2010, 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 02110-1335 USA */
/**
@file
File containing constants that can be used throughout the server.
@note This file shall not contain or include any declarations of any kinds.
*/
#ifndef SQL_CONST_INCLUDED
#define SQL_CONST_INCLUDED
#include <mysql_version.h>
#define LIBLEN FN_REFLEN-FN_LEN /* Max l{ngd p} dev */
/* extra 4+4 bytes for slave tmp tables */
#define MAX_DBKEY_LENGTH (NAME_LEN*2+1+1+4+4)
#define MAX_ALIAS_NAME 256
#define MAX_FIELD_NAME (NAME_LEN+1) /* Max column name length +1 */
#define MAX_SYS_VAR_LENGTH 32
#define MAX_KEY MAX_INDEXES /* Max used keys */
#define MAX_REF_PARTS 32 /* Max parts used as ref */
/*
Maximum length of the data part of an index lookup key.
The "data part" is defined as the value itself, not including the
NULL-indicator bytes or varchar length bytes ("the Extras"). We need this
value because there was a bug where length of the Extras were not counted.
You probably need MAX_KEY_LENGTH, not this constant.
*/
#define MAX_DATA_LENGTH_FOR_KEY 3072
#if SIZEOF_OFF_T > 4
#define MAX_REFLENGTH 8 /* Max length for record ref */
#else
#define MAX_REFLENGTH 4 /* Max length for record ref */
#endif
#define MAX_HOSTNAME (HOSTNAME_LENGTH + 1) /* len+1 in mysql.user */
#define MAX_CONNECTION_NAME NAME_LEN
#define MAX_MBWIDTH 3 /* Max multibyte sequence */
#define MAX_FILENAME_MBWIDTH 5
#define MAX_FIELD_CHARLENGTH 255
/*
In MAX_FIELD_VARCHARLENGTH we reserve extra bytes for the overhead:
- 2 bytes for the length
- 1 byte for NULL bits
to avoid the "Row size too large" error for these three corner definitions:
CREATE TABLE t1 (c VARBINARY(65533));
CREATE TABLE t1 (c VARBINARY(65534));
CREATE TABLE t1 (c VARBINARY(65535));
Like VARCHAR(65536), they will be converted to BLOB automatically
in non-strict mode.
*/
#define MAX_FIELD_VARCHARLENGTH (65535-2-1)
#define MAX_FIELD_BLOBLENGTH UINT_MAX32 /* cf field_blob::get_length() */
#define CONVERT_IF_BIGGER_TO_BLOB 512 /* Threshold *in characters* */
/* Max column width +1 */
#define MAX_FIELD_WIDTH (MAX_FIELD_CHARLENGTH*MAX_MBWIDTH+1)
#define MAX_BIT_FIELD_LENGTH 64 /* Max length in bits for bit fields */
#define MAX_DATE_WIDTH 10 /* YYYY-MM-DD */
#define MIN_TIME_WIDTH 10 /* -HHH:MM:SS */
#define MAX_TIME_WIDTH 16 /* -DDDDDD HH:MM:SS */
#define MAX_TIME_FULL_WIDTH 23 /* -DDDDDD HH:MM:SS.###### */
#define MAX_DATETIME_FULL_WIDTH 26 /* YYYY-MM-DD HH:MM:SS.###### */
#define MAX_DATETIME_WIDTH 19 /* YYYY-MM-DD HH:MM:SS */
#define MAX_DATETIME_COMPRESSED_WIDTH 14 /* YYYYMMDDHHMMSS */
#define MAX_DATETIME_PRECISION 6
#define MAX_TABLES (sizeof(table_map)*8-3) /* Max tables in join */
#define PARAM_TABLE_BIT (((table_map) 1) << (sizeof(table_map)*8-3))
#define OUTER_REF_TABLE_BIT (((table_map) 1) << (sizeof(table_map)*8-2))
#define RAND_TABLE_BIT (((table_map) 1) << (sizeof(table_map)*8-1))
#define PSEUDO_TABLE_BITS (PARAM_TABLE_BIT | OUTER_REF_TABLE_BIT | \
RAND_TABLE_BIT)
#define CONNECT_STRING_MAXLEN 65535 /* stored in 2 bytes in .frm */
#define MAX_FIELDS 4096 /* Limit in the .frm file */
#define MAX_PARTITIONS 8192
#define MAX_SELECT_NESTING (SELECT_NESTING_MAP_SIZE - 1)
#define MAX_SORT_MEMORY 2048*1024
#define MIN_SORT_MEMORY 1024
/* Some portable defines */
#define STRING_BUFFER_USUAL_SIZE 80
/* Memory allocated when parsing a statement / saving a statement */
#define MEM_ROOT_BLOCK_SIZE 8192
#define MEM_ROOT_PREALLOC 8192
#define TRANS_MEM_ROOT_BLOCK_SIZE 4096
#define TRANS_MEM_ROOT_PREALLOC 4096
#define DEFAULT_ERROR_COUNT 64
#define EXTRA_RECORDS 10 /* Extra records in sort */
#define SCROLL_EXTRA 5 /* Extra scroll-rows. */
#define FIELD_NAME_USED ((uint) 32768) /* Bit set if fieldname used */
#define FORM_NAME_USED ((uint) 16384) /* Bit set if formname used */
#define FIELD_NR_MASK 16383 /* To get fieldnumber */
#define FERR -1 /* Error from my_functions */
#define CREATE_MODE 0 /* Default mode on new files */
#define NAMES_SEP_CHAR 255 /* Char to sep. names */
/*
This is used when reading large blocks, sequential read.
We assume that reading this much will be roughly the same cost as 1
seek / fetching one row from the storage engine.
Cost of one read of DISK_CHUNK_SIZE is DISK_SEEK_BASE_COST (ms).
*/
#define DISK_CHUNK_SIZE (uint) (65536) /* Size of diskbuffer for tmpfiles */
#define FRM_VER_TRUE_VARCHAR (FRM_VER+4) /* 10 */
#define FRM_VER_EXPRESSSIONS (FRM_VER+5) /* 11 */
#define FRM_VER_CURRENT FRM_VER_EXPRESSSIONS
/***************************************************************************
Configuration parameters
****************************************************************************/
#define ACL_CACHE_SIZE 256
#define MAX_PASSWORD_LENGTH 32
#define HOST_CACHE_SIZE 128
#define MAX_ACCEPT_RETRY 10 // Test accept this many times
#define MAX_FIELDS_BEFORE_HASH 32
#define USER_VARS_HASH_SIZE 16
#define SEQUENCES_HASH_SIZE 16
#define TABLE_OPEN_CACHE_MIN 200
#define TABLE_OPEN_CACHE_DEFAULT 2000
#define TABLE_DEF_CACHE_DEFAULT 400
/**
We must have room for at least 400 table definitions in the table
cache, since otherwise there is no chance prepared
statements that use these many tables can work.
Prepared statements use table definition cache ids (table_map_id)
as table version identifiers. If the table definition
cache size is less than the number of tables used in a statement,
the contents of the table definition cache is guaranteed to rotate
between a prepare and execute. This leads to stable validation
errors. In future we shall use more stable version identifiers,
for now the only solution is to ensure that the table definition
cache can contain at least all tables of a given statement.
*/
#define TABLE_DEF_CACHE_MIN 400
/**
Maximum number of connections default value.
151 is larger than Apache's default max children,
to avoid "too many connections" error in a common setup.
*/
#define MAX_CONNECTIONS_DEFAULT 151
/*
Stack reservation.
Feel free to raise this by the smallest amount you can to get the
"execution_constants" test to pass.
*/
#define STACK_MIN_SIZE 16000 // Abort if less stack during eval.
#define STACK_MIN_SIZE_FOR_OPEN (1024*80)
#define STACK_BUFF_ALLOC 352 ///< For stack overrun checks
#ifndef MYSQLD_NET_RETRY_COUNT
#define MYSQLD_NET_RETRY_COUNT 10 ///< Abort read after this many int.
#endif
/*
Allocations with MEM_ROOT. We should try to keep these as powers of 2
and not higher than 32768 to get full benefit of allocators like
tcmalloc that will for these use a local heap without locks.
*/
#define QUERY_ALLOC_BLOCK_SIZE 32768
#define QUERY_ALLOC_PREALLOC_SIZE 32768 /* 65536 could be better */
#define TRANS_ALLOC_BLOCK_SIZE 8192
#define TRANS_ALLOC_PREALLOC_SIZE 4096
#define RANGE_ALLOC_BLOCK_SIZE 4096
#define ACL_ALLOC_BLOCK_SIZE 1024
#define UDF_ALLOC_BLOCK_SIZE 1024
#define TABLE_PREALLOC_BLOCK_SIZE 8192
#define TABLE_ALLOC_BLOCK_SIZE 4096
#define WARN_ALLOC_BLOCK_SIZE 2048
#define WARN_ALLOC_PREALLOC_SIZE 1024
#define TMP_TABLE_BLOCK_SIZE 16384
#define TMP_TABLE_PREALLOC_SIZE 32768
#define SHOW_ALLOC_BLOCK_SIZE 32768
/*
The following parameters is to decide when to use an extra cache to
optimise seeks when reading a big table in sorted order
*/
#define MIN_FILE_LENGTH_TO_USE_ROW_CACHE (10L*1024*1024)
#define MIN_ROWS_TO_USE_TABLE_CACHE 100
#define MIN_ROWS_TO_USE_BULK_INSERT 100
/*
The lower bound of accepted rows when using filter.
This is used to ensure that filters are not too aggressive.
*/
#define MIN_ROWS_AFTER_FILTERING 1.0
/**
Number of rows in a reference table when referred through a not unique key.
This value is only used when we don't know anything about the key
distribution.
*/
#define MATCHING_ROWS_IN_OTHER_TABLE 10
#define MY_CHARSET_BIN_MB_MAXLEN 1
/** Don't pack string keys shorter than this (if PACK_KEYS=1 isn't used). */
#define KEY_DEFAULT_PACK_LENGTH 8
/** Characters shown for the command in 'show processlist'. */
#define PROCESS_LIST_WIDTH 100
/* Characters shown for the command in 'information_schema.processlist' */
#define PROCESS_LIST_INFO_WIDTH 65535
#define PRECISION_FOR_DOUBLE 53
#define PRECISION_FOR_FLOAT 24
/* -[digits].E+## */
#define MAX_FLOAT_STR_LENGTH (FLT_DIG + 6)
/* -[digits].E+### */
#define MAX_DOUBLE_STR_LENGTH (DBL_DIG + 7)
/*
Default time to wait before aborting a new client connection
that does not respond to "initial server greeting" timely
*/
#define CONNECT_TIMEOUT 10
/* Wait 5 minutes before removing thread from thread cache */
#define THREAD_CACHE_TIMEOUT 5*60
/* The following can also be changed from the command line */
#define DEFAULT_CONCURRENCY 10
#define DELAYED_LIMIT 100 /**< pause after xxx inserts */
#define DELAYED_QUEUE_SIZE 1000
#define DELAYED_WAIT_TIMEOUT (5*60) /**< Wait for delayed insert */
#define MAX_CONNECT_ERRORS 100 ///< errors before disabling host
#define LONG_TIMEOUT ((ulong) 3600L*24L*365L)
/**
Maximum length of time zone name that we support (Time zone name is
char(64) in db). mysqlbinlog needs it.
*/
#define MAX_TIME_ZONE_NAME_LENGTH (NAME_LEN + 1)
#define SP_PSI_STATEMENT_INFO_COUNT 24
#endif /* SQL_CONST_INCLUDED */
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