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813fc4104e
cursor is interpreted latin1 character and Bug#9819 "Cursors: Mysql Server
Crash while fetching from table with 5 million records."
A fix for a possible memory leak when fetching into an SP cursor
in a long loop.
The patch uses a common implementation of cursors in the binary protocol and
in stored procedures and implements materialized cursors.
For implementation details, see comments in sql_cursor.cc
include/my_sys.h:
- declaration for multi_alloc_root
libmysqld/Makefile.am:
- drop protocol_cursor.cc, add sql_cursor.cc (replaces the old
implementation of cursors with a new one)
mysql-test/r/ctype_ujis.result:
- test results fixed (a test case for Bug#6513)
mysql-test/r/sp-big.result:
- test results fixed (a test case for Bug#9819)
mysql-test/t/ctype_ujis.test:
Add a test case for Bug#6513 "Test Suite: Values inserted by using cursor is
interpreted latin1 character"
mysql-test/t/sp-big.test:
Add a restricted test case for Bug#9819 "Cursors: Mysql Server Crash
while fetching from table with 5 million records."
mysys/my_alloc.c:
- an implementation of multi_alloc_root; this is largely a copy-paste
from mulalloc.c, but the function is small and there is no easy way
to reuse the existing C function.
sql/Makefile.am:
- add sql_cursor.h, sql_cursor.cc (a new implementation of stored procedure
cursors) and drop protocol_cursor.cc (the old one)
sql/handler.cc:
- now TABLE object has its mem_root always initialized.
Adjust the implementation handler::ha_open
sql/item_subselect.cc:
- adjust to the changed declaration of st_select_lex_unit::prepare
sql/protocol.h:
- drop Protocol_cursor
sql/sp_head.cc:
- move juggling with Query_arena::free_list and Item::next to
sp_eval_func_item, as this is needed in 3 places already.
sql/sp_head.h:
- declare a no-op implementation for cleanup_stmt in sp_instr_cpush.
This method is needed for non-materializing cursors, which are yet not
used in stored procedures.
- declaration for sp_eval_func_item
sql/sp_rcontext.cc:
- reimplement sp_cursor using the new implementation of server side cursors.
- use sp_eval_func_item to assign values of SP variables from the
row fetched from a cursor. This should fix a possible memory leak in
the old implementation of sp_cursor::fetch
sql/sp_rcontext.h:
- reimplement sp_cursor using the new implementation of server side cursors.
sql/sql_class.cc:
- disable the functionality that closes transient cursors at commit/rollback;
transient cursors are not used in 5.0, instead we use materialized ones.
To be enabled in a later version.
sql/sql_class.h:
- adjust to the rename Cursor -> Server_side_cursor
- additional declarations of select_union used in materialized cursors
sql/sql_derived.cc:
- reuse bits of tmp table code in UNION, derived tables, and materialized
cursors
- cleanup comments
sql/sql_lex.h:
- declarations of auxiliary methods used by materialized cursors
- a cleanup in st_select_lex_unit interface
sql/sql_list.h:
- add an array operator new[] to class Sql_alloc
sql/sql_prepare.cc:
- split the tight coupling of cursors and prepared statements to reuse
the same implementation in stored procedures
- cleanups of error processing in Prepared_statement::{prepare,execute}
sql/sql_select.cc:
- move the implementation of sensitive (non-materializing) cursors to
sql_cursor.cc
- make temporary tables self-contained: the table, its record and fields
are allocated in TABLE::mem_root. This implementation is not clean
and resets thd->mem_root several times because of the way create_tmp_table
works (many additional things are done inside it).
- adjust to the changed declaration of st_select_lex_unit::prepare
sql/sql_select.h:
- move the declaration of sensitive (non-materializing) cursors to
sql_cursor.cc
sql/sql_union.cc:
- move pieces of st_select_unit::prepare to select_union and st_table
methods to be able to reuse code in the implementation of materialized
cursors
sql/sql_view.cc:
- adjust to the changed signature of st_select_lex_unit::prepare
sql/table.cc:
- implement auxiliary st_table methods for use with temporary tables
sql/table.h:
- add declarations for auxiliary methods of st_table used to work with
temporary tables
tests/mysql_client_test.c:
- if cursors are materialized, a parallel update of the table used
in the cursor may go through: update the test.
sql/sql_cursor.cc:
New BitKeeper file ``sql/sql_cursor.cc'' -- implementation of server side
cursors
sql/sql_cursor.h:
New BitKeeper file ``sql/sql_cursor.h'' - declarations for
server side cursors.
66 lines
2.1 KiB
C++
66 lines
2.1 KiB
C++
#ifndef _sql_cursor_h_
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#define _sql_cursor_h_
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/* Copyright (C) 2005 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
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#ifdef USE_PRAGMA_INTERFACE
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#pragma interface /* gcc class interface */
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#endif
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/*
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Declarations for implementation of server side cursors. Only
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read-only non-scrollable cursors are currently implemented.
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*/
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/*
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Server_side_cursor -- an interface for materialized and
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sensitive (non-materialized) implementation of cursors. All
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cursors are self-contained (created in their own memory root).
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For that reason they must be deleted only using a pointer to
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Server_side_cursor, not to its base class.
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*/
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class Server_side_cursor: protected Query_arena, public Sql_alloc
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{
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protected:
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/* Row destination used for fetch */
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select_result *result;
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public:
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Server_side_cursor(MEM_ROOT *mem_root_arg, select_result *result_arg)
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:Query_arena(mem_root_arg, INITIALIZED), result(result_arg)
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{}
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virtual bool is_open() const= 0;
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virtual int open(JOIN *top_level_join)= 0;
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virtual void fetch(ulong num_rows)= 0;
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virtual void close()= 0;
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virtual ~Server_side_cursor();
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static void operator delete(void *ptr, size_t size);
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};
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int mysql_open_cursor(THD *thd, uint flags,
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select_result *result,
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Server_side_cursor **res);
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/* Possible values for flags */
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enum { ANY_CURSOR= 1, ALWAYS_MATERIALIZED_CURSOR= 2 };
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#endif /* _sql_cusor_h_ */
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