mysql5/mysql-5.7.27/storage/perfschema/table_status_by_thread.h

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3.7 KiB
C++

/* Copyright (c) 2015, 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 02110-1301 USA */
#ifndef TABLE_STATUS_BY_THREAD_H
#define TABLE_STATUS_BY_THREAD_H
/**
@file storage/perfschema/table_status_by_thread.h
Table STATUS_BY_THREAD (declarations).
*/
#include "pfs_column_types.h"
#include "pfs_engine_table.h"
#include "pfs_instr_class.h"
#include "pfs_instr.h"
#include "table_helper.h"
#include "pfs_variable.h"
#include "pfs_buffer_container.h"
/**
@addtogroup Performance_schema_tables
@{
*/
/**
A row of table
PERFORMANCE_SCHEMA.STATUS_BY_THREAD.
*/
struct row_status_by_thread
{
/** Column THREAD_ID. */
ulonglong m_thread_internal_id;
/** Column VARIABLE_NAME. */
PFS_variable_name_row m_variable_name;
/** Column VARIABLE_VALUE. */
PFS_variable_value_row m_variable_value;
};
/**
Position of a cursor on
PERFORMANCE_SCHEMA.STATUS_BY_THREAD.
Index 1 on thread (0 based)
Index 2 on status variable (0 based)
*/
struct pos_status_by_thread
: public PFS_double_index
{
pos_status_by_thread()
: PFS_double_index(0, 0)
{}
inline void reset(void)
{
m_index_1= 0;
m_index_2= 0;
}
inline bool has_more_thread(void)
{ return (m_index_1 < global_thread_container.get_row_count()); }
inline void next_thread(void)
{
m_index_1++;
m_index_2= 0;
}
};
/**
Store and retrieve table state information for queries that reinstantiate
the table object.
*/
class table_status_by_thread_context : public PFS_table_context
{
public:
table_status_by_thread_context(ulonglong current_version, bool restore) :
PFS_table_context(current_version, global_thread_container.get_row_count(), restore, THR_PFS_SBT) { }
};
/** Table PERFORMANCE_SCHEMA.STATUS_BY_THREAD. */
class table_status_by_thread : public PFS_engine_table
{
typedef pos_status_by_thread pos_t;
public:
/** Table share */
static PFS_engine_table_share m_share;
static PFS_engine_table* create();
static int delete_all_rows();
static ha_rows get_row_count();
virtual int rnd_init(bool scan);
virtual int rnd_next();
virtual int rnd_pos(const void *pos);
virtual void reset_position(void);
protected:
virtual int read_row_values(TABLE *table,
unsigned char *buf,
Field **fields,
bool read_all);
table_status_by_thread();
public:
~table_status_by_thread()
{}
protected:
int materialize(PFS_thread *thread);
void make_row(PFS_thread *thread, const Status_variable *status_var);
private:
/** Table share lock. */
static THR_LOCK m_table_lock;
/** Fields definition. */
static TABLE_FIELD_DEF m_field_def;
/** Current THD variables. */
PFS_status_variable_cache m_status_cache;
/** Current row. */
row_status_by_thread m_row;
/** True if the current row exists. */
bool m_row_exists;
/** Current position. */
pos_t m_pos;
/** Next position. */
pos_t m_next_pos;
/** Table context with global status array version and map of materialized threads. */
table_status_by_thread_context *m_context;
};
/** @} */
#endif