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Diffstat (limited to '')
| -rw-r--r-- | storage/perfschema/table_global_variables.cc | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/storage/perfschema/table_global_variables.cc b/storage/perfschema/table_global_variables.cc new file mode 100644 index 00000000..117e06e3 --- /dev/null +++ b/storage/perfschema/table_global_variables.cc @@ -0,0 +1,184 @@ +/* Copyright (c) 2015, 2018, 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, 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; + +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, + { C_STRING_WITH_LEN("CREATE TABLE global_variables(" + "VARIABLE_NAME VARCHAR(64) not null," + "VARIABLE_VALUE VARCHAR(1024))") }, + 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_prlock_rdlock(&LOCK_system_variables_hash); + ha_rows system_var_count= get_system_variable_hash_records(); + mysql_prlock_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); + DBUG_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 */ + DBUG_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: + DBUG_ASSERT(false); + } + } + } + + return 0; +} + |