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Backport of:

----------------------------------------------------------
revno: 2617.69.24
committer: Konstantin Osipov <kostja@sun.com>
branch nick: 5.4-42546
timestamp: Fri 2009-08-14 19:22:05 +0400
message:
  A pre-requisite for a fix for Bug#42546 "Backup: RESTORE fails, thinking it
  finds an existing table"
  Back-port from WL 148 "Foreign keys" feature tree a patch
  that introduced Prelocking_strategy class -- a way to parameterize
  open_tables() behaviour, implemented by Dmitry Lenev.

(Part of WL#4284).
This commit is contained in:
Konstantin Osipov
2009-12-08 17:13:12 +03:00
parent b9895d46c1
commit c20afa6d49
12 changed files with 790 additions and 418 deletions

View File

@ -38,6 +38,7 @@ class sp_rcontext;
class sp_cache;
class Parser_state;
class Rows_log_event;
class Sroutine_hash_entry;
enum enum_enable_or_disable { LEAVE_AS_IS, ENABLE, DISABLE };
enum enum_ha_read_modes { RFIRST, RNEXT, RPREV, RLAST, RKEY, RNEXT_SAME };
@ -1181,6 +1182,89 @@ private:
};
/**
An abstract class for a strategy specifying how the prelocking
algorithm should extend the prelocking set while processing
already existing elements in the set.
*/
class Prelocking_strategy
{
public:
virtual ~Prelocking_strategy() { }
virtual bool handle_routine(THD *thd, Query_tables_list *prelocking_ctx,
Sroutine_hash_entry *rt, sp_head *sp,
bool *need_prelocking) = 0;
virtual bool handle_table(THD *thd, Query_tables_list *prelocking_ctx,
TABLE_LIST *table_list, bool *need_prelocking) = 0;
virtual bool handle_view(THD *thd, Query_tables_list *prelocking_ctx,
TABLE_LIST *table_list, bool *need_prelocking)= 0;
};
/**
A Strategy for prelocking algorithm suitable for DML statements.
Ensures that all tables used by all statement's SF/SP/triggers and
required for foreign key checks are prelocked and SF/SPs used are
cached.
*/
class DML_prelocking_strategy : public Prelocking_strategy
{
public:
virtual bool handle_routine(THD *thd, Query_tables_list *prelocking_ctx,
Sroutine_hash_entry *rt, sp_head *sp,
bool *need_prelocking);
virtual bool handle_table(THD *thd, Query_tables_list *prelocking_ctx,
TABLE_LIST *table_list, bool *need_prelocking);
virtual bool handle_view(THD *thd, Query_tables_list *prelocking_ctx,
TABLE_LIST *table_list, bool *need_prelocking);
};
/**
A strategy for prelocking algorithm to be used for LOCK TABLES
statement.
*/
class Lock_tables_prelocking_strategy : public DML_prelocking_strategy
{
virtual bool handle_table(THD *thd, Query_tables_list *prelocking_ctx,
TABLE_LIST *table_list, bool *need_prelocking);
};
/**
Strategy for prelocking algorithm to be used for ALTER TABLE statements.
Unlike DML or LOCK TABLES strategy, it doesn't
prelock triggers, views or stored routines, since they are not
used during ALTER.
*/
class Alter_table_prelocking_strategy : public Prelocking_strategy
{
public:
Alter_table_prelocking_strategy(Alter_info *alter_info)
: m_alter_info(alter_info)
{}
virtual bool handle_routine(THD *thd, Query_tables_list *prelocking_ctx,
Sroutine_hash_entry *rt, sp_head *sp,
bool *need_prelocking);
virtual bool handle_table(THD *thd, Query_tables_list *prelocking_ctx,
TABLE_LIST *table_list, bool *need_prelocking);
virtual bool handle_view(THD *thd, Query_tables_list *prelocking_ctx,
TABLE_LIST *table_list, bool *need_prelocking);
private:
Alter_info *m_alter_info;
};
/**
A context of open_tables() function, used to recover
from a failed open_table() attempt.