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Merge bk-internal.mysql.com:/home/bk/mysql-5.1

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into  bodhi.(none):/opt/local/work/mysql-5.1-27430
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kostja@bodhi.(none)
2008-04-19 14:37:20 +04:00
parent 013fd23675 78e4f40173
commit db70574976
39 changed files with 4385 additions and 4779 deletions
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67
sql/sql_class.h
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@ -23,6 +23,53 @@
#include "log.h"
#include "rpl_tblmap.h"
/**
An abstract interface that can be used to take an action when
the locking module notices that a table version has changed
since the last execution. "Table" here may refer to any kind of
table -- a base table, a temporary table, a view or an
information schema table.
When we open and lock tables for execution of a prepared
statement, we must verify that they did not change
since statement prepare. If some table did change, the statement
parse tree *may* be no longer valid, e.g. in case it contains
optimizations that depend on table metadata.
This class provides an abstract interface (a method) that is
invoked when such a situation takes place.
The implementation of the interface in most cases simply
reports an error, but the exact details depend on the nature of
the SQL statement.
At most 1 instance of this class is active at a time, in which
case THD::m_metadata_observer is not NULL.
@sa check_and_update_table_version() for details of the
version tracking algorithm
@sa Execute_observer for details of how we detect that
a metadata change is fatal and a re-prepare is necessary
@sa Open_tables_state::m_metadata_observer for the life cycle
of metadata observers.
*/
class Metadata_version_observer
{
protected:
virtual ~Metadata_version_observer();
public:
/**
Check if a change of metadata is OK. In future
the signature of this method may be extended to accept the old
and the new versions, but since currently the check is very
simple, we only need the THD to report an error.
*/
virtual bool check_metadata_change(THD *thd)= 0;
};
class Relay_log_info;
class Query_log_event;
@ -406,6 +453,7 @@ typedef struct system_status_var
ulong filesort_scan_count;
/* Prepared statements and binary protocol */
ulong com_stmt_prepare;
ulong com_stmt_reprepare;
ulong com_stmt_execute;
ulong com_stmt_send_long_data;
ulong com_stmt_fetch;
@ -436,7 +484,7 @@ void free_tmp_table(THD *thd, TABLE *entry);
/* The following macro is to make init of Query_arena simpler */
#ifndef DBUG_OFF
#define INIT_ARENA_DBUG_INFO is_backup_arena= 0
#define INIT_ARENA_DBUG_INFO is_backup_arena= 0; is_reprepared= FALSE;
#else
#define INIT_ARENA_DBUG_INFO
#endif
@ -452,6 +500,7 @@ public:
MEM_ROOT *mem_root; // Pointer to current memroot
#ifndef DBUG_OFF
bool is_backup_arena; /* True if this arena is used for backup. */
bool is_reprepared;
#endif
/*
The states relfects three diffrent life cycles for three
@ -788,6 +837,20 @@ enum prelocked_mode_type {NON_PRELOCKED= 0, PRELOCKED= 1,
class Open_tables_state
{
public:
/**
As part of class THD, this member is set during execution
of a prepared statement. When it is set, it is used
by the locking subsystem to report a change in table metadata.
When Open_tables_state part of THD is reset to open
a system or INFORMATION_SCHEMA table, the member is cleared
to avoid spurious ER_NEED_REPREPARE errors -- system and
INFORMATION_SCHEMA tables are not subject to metadata version
tracking.
@sa check_and_update_table_version()
*/
Metadata_version_observer *m_metadata_observer;
/**
List of regular tables in use by this thread. Contains temporary and
base tables that were opened with @see open_tables().
@ -891,6 +954,7 @@ public:
extra_lock= lock= locked_tables= 0;
prelocked_mode= NON_PRELOCKED;
state_flags= 0U;
m_metadata_observer= NULL;
}
};
@ -2778,6 +2842,7 @@ public:
#define CF_STATUS_COMMAND 4
#define CF_SHOW_TABLE_COMMAND 8
#define CF_WRITE_LOGS_COMMAND 16
#define CF_REEXECUTION_FRAGILE 32
/* Functions in sql_class.cc */