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- /* Copyright (c) 2015, 2021, Oracle and/or its affiliates.
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License, version 2.0,
- as published by the Free Software Foundation.
-
- This program is also distributed with certain software (including
- but not limited to OpenSSL) that is licensed under separate terms,
- as designated in a particular file or component or in included license
- documentation. The authors of MySQL hereby grant you an additional
- permission to link the program and your derivative works with the
- separately licensed software that they have included with MySQL.
-
- 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, version 2.0, 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 */
-
- /**
- @file storage/perfschema/table_global_variables.cc
- Table GLOBAL_VARIABLES (implementation).
- */
-
- #include "my_global.h"
- #include "table_global_variables.h"
- #include "my_thread.h"
- #include "pfs_instr_class.h"
- #include "pfs_column_types.h"
- #include "pfs_column_values.h"
- #include "pfs_global.h"
-
- THR_LOCK table_global_variables::m_table_lock;
-
- static const TABLE_FIELD_TYPE field_types[]=
- {
- {
- { C_STRING_WITH_LEN("VARIABLE_NAME") },
- { C_STRING_WITH_LEN("varchar(64)") },
- { NULL, 0}
- },
- {
- { C_STRING_WITH_LEN("VARIABLE_VALUE") },
- { C_STRING_WITH_LEN("varchar(1024)") },
- { NULL, 0}
- }
- };
-
- TABLE_FIELD_DEF
- table_global_variables::m_field_def=
- { 2, field_types };
-
- PFS_engine_table_share
- table_global_variables::m_share=
- {
- { C_STRING_WITH_LEN("global_variables") },
- &pfs_readonly_world_acl,
- table_global_variables::create,
- NULL, /* write_row */
- NULL, /* delete_all_rows */
- table_global_variables::get_row_count,
- sizeof(pos_t),
- &m_table_lock,
- &m_field_def,
- false, /* checked */
- true /* perpetual */
- };
-
- PFS_engine_table*
- table_global_variables::create(void)
- {
- return new table_global_variables();
- }
-
- ha_rows table_global_variables::get_row_count(void)
- {
- mysql_mutex_lock(&LOCK_plugin_delete);
- mysql_rwlock_rdlock(&LOCK_system_variables_hash);
- ha_rows system_var_count= get_system_variable_hash_records();
- mysql_rwlock_unlock(&LOCK_system_variables_hash);
- mysql_mutex_unlock(&LOCK_plugin_delete);
- return system_var_count;
- }
-
- table_global_variables::table_global_variables()
- : PFS_engine_table(&m_share, &m_pos),
- m_sysvar_cache(false), m_row_exists(false), m_pos(0), m_next_pos(0)
- {}
-
- void table_global_variables::reset_position(void)
- {
- m_pos.m_index= 0;
- m_next_pos.m_index= 0;
- }
-
- int table_global_variables::rnd_init(bool scan)
- {
- /*
- Build a list of system variables from the global system variable hash.
- Filter by scope.
- */
- m_sysvar_cache.materialize_global();
-
- /* Record the version of the system variable hash. */
- ulonglong hash_version= m_sysvar_cache.get_sysvar_hash_version();
-
- /*
- The table context holds the current version of the system variable hash.
- If scan == true, then allocate a new context from mem_root and store in TLS.
- If scan == false, then restore from TLS.
- */
- m_context= (table_global_variables_context *)current_thd->alloc(sizeof(table_global_variables_context));
- new(m_context) table_global_variables_context(hash_version, !scan);
- return 0;
- }
-
- int table_global_variables::rnd_next(void)
- {
- for (m_pos.set_at(&m_next_pos);
- m_pos.m_index < m_sysvar_cache.size();
- m_pos.next())
- {
- const System_variable *system_var= m_sysvar_cache.get(m_pos.m_index);
- if (system_var != NULL)
- {
- make_row(system_var);
- m_next_pos.set_after(&m_pos);
- return 0;
- }
- }
- return HA_ERR_END_OF_FILE;
- }
-
- int table_global_variables::rnd_pos(const void *pos)
- {
- /* If system variable hash changes, do nothing. */ // TODO: Issue warning
- if (!m_context->versions_match())
- return HA_ERR_RECORD_DELETED;
-
- set_position(pos);
- assert(m_pos.m_index < m_sysvar_cache.size());
-
- const System_variable *system_var= m_sysvar_cache.get(m_pos.m_index);
- if (system_var != NULL)
- {
- make_row(system_var);
- return 0;
- }
- return HA_ERR_RECORD_DELETED;
- }
-
- void table_global_variables
- ::make_row(const System_variable *system_var)
- {
- m_row_exists= false;
- if (system_var->is_null() || system_var->is_ignored())
- return;
- m_row.m_variable_name.make_row(system_var->m_name, system_var->m_name_length);
- m_row.m_variable_value.make_row(system_var);
- m_row_exists= true;
- }
-
- int table_global_variables
- ::read_row_values(TABLE *table,
- unsigned char *buf,
- Field **fields,
- bool read_all)
- {
- Field *f;
-
- if (unlikely(! m_row_exists))
- return HA_ERR_RECORD_DELETED;
-
- /* Set the null bits */
- assert(table->s->null_bytes == 1);
- buf[0]= 0;
-
- for (; (f= *fields) ; fields++)
- {
- if (read_all || bitmap_is_set(table->read_set, f->field_index))
- {
- switch(f->field_index)
- {
- case 0: /* VARIABLE_NAME */
- set_field_varchar_utf8(f, m_row.m_variable_name.m_str, m_row.m_variable_name.m_length);
- break;
- case 1: /* VARIABLE_VALUE */
- m_row.m_variable_value.set_field(f);
- break;
- default:
- assert(false);
- }
- }
- }
-
- return 0;
- }
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