1 files changed, 543 insertions, 0 deletions
diff --git a/storage/perfschema/ha_perfschema.cc b/storage/perfschema/ha_perfschema.cc
new file mode 100644
index 00000000..c6d2f23d
--- /dev/null
+++ b/storage/perfschema/ha_perfschema.cc
@@ -0,0 +1,543 @@
+/* Copyright (c) 2008, 2023, 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,
+  51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
+
+/**
+  @file storage/perfschema/ha_perfschema.cc
+  Performance schema storage engine (implementation).
+*/
+
+#include "sql_plugin.h"
+#include "my_pthread.h"
+#include "ha_perfschema.h"
+#include "pfs_engine_table.h"
+#include "pfs_column_values.h"
+#include "pfs_instr_class.h"
+#include "pfs_instr.h"
+#include "pfs_account.h"
+#include "pfs_host.h"
+#include "pfs_user.h"
+#include "pfs_program.h"
+#include "pfs_prepared_stmt.h"
+#include "pfs_buffer_container.h"
+
+handlerton *pfs_hton= NULL;
+
+#define PFS_ENABLED() (pfs_initialized && (pfs_enabled || m_table_share->m_perpetual))
+
+static handler* pfs_create_handler(handlerton *hton,
+                                   TABLE_SHARE *table,
+                                   MEM_ROOT *mem_root)
+{
+  return new (mem_root) ha_perfschema(hton, table);
+}
+
+static int compare_database_names(const char *name1, const char *name2)
+{
+  if (lower_case_table_names)
+    return strcasecmp(name1, name2);
+  return strcmp(name1, name2);
+}
+
+static const PFS_engine_table_share*
+find_table_share(const char *db, const char *name)
+{
+  DBUG_ENTER("find_table_share");
+
+  if (compare_database_names(db, PERFORMANCE_SCHEMA_str.str) != 0)
+    DBUG_RETURN(NULL);
+
+  const PFS_engine_table_share* result;
+  result= PFS_engine_table::find_engine_table_share(name);
+  DBUG_RETURN(result);
+}
+
+static int pfs_discover_table(handlerton *hton, THD *thd, TABLE_SHARE *share)
+{
+  const PFS_engine_table_share *pfs_share;
+
+  if ((pfs_share= find_table_share(share->db.str, share->table_name.str)))
+    return share->init_from_sql_statement_string(thd, false,
+                                                 pfs_share->sql.str,
+                                                 pfs_share->sql.length);
+  return HA_ERR_NO_SUCH_TABLE;
+}
+
+static int pfs_discover_table_existence(handlerton *hton, const char *db,
+                                        const char *table_name)
+{
+  return MY_TEST(find_table_share(db, table_name));
+}
+
+static int pfs_init_func(void *p)
+{
+  DBUG_ENTER("pfs_init_func");
+
+  pfs_hton= reinterpret_cast<handlerton *> (p);
+
+  pfs_hton->create= pfs_create_handler;
+  pfs_hton->drop_table= [](handlerton *, const char*) { return -1; };
+  pfs_hton->show_status= pfs_show_status;
+  pfs_hton->flags= HTON_ALTER_NOT_SUPPORTED | HTON_TEMPORARY_NOT_SUPPORTED |
+                   HTON_NO_PARTITION | HTON_NO_BINLOG_ROW_OPT;
+
+  /*
+    As long as the server implementation keeps using legacy_db_type,
+    as for example in mysql_truncate(),
+    we can not rely on the fact that different mysqld process will assign
+    consistently the same legacy_db_type for a given storage engine name.
+    In particular, using different --loose-skip-xxx options between
+    ./mysqld --bootstrap
+    ./mysqld
+    creates bogus .frm forms when bootstrapping the performance schema,
+    if we rely on ha_initialize_handlerton to assign a really dynamic value.
+    To fix this, a dedicated DB_TYPE is officially assigned to
+    the performance schema. See Bug#43039.
+  */
+  pfs_hton->db_type= DB_TYPE_PERFORMANCE_SCHEMA;
+  pfs_hton->discover_table= pfs_discover_table;
+  pfs_hton->discover_table_existence= pfs_discover_table_existence;
+  pfs_hton->discover_table_names= pfs_discover_table_names;
+
+  PFS_engine_table_share::init_all_locks();
+
+  DBUG_RETURN(0);
+}
+
+static int pfs_done_func(void *p)
+{
+  DBUG_ENTER("pfs_done_func");
+
+  pfs_hton= NULL;
+
+  PFS_engine_table_share::delete_all_locks();
+
+  DBUG_RETURN(0);
+}
+
+static int show_func_mutex_instances_lost(THD *thd, SHOW_VAR *var, char *buff)
+{
+  var->type= SHOW_LONG;
+  var->value= buff;
+  long *value= reinterpret_cast<long*>(buff);
+  *value= global_mutex_container.get_lost_counter();
+  return 0;
+}
+
+static struct st_mysql_show_var pfs_status_vars[]=
+{
+  {"Performance_schema_mutex_classes_lost",
+    (char*) &mutex_class_lost, SHOW_LONG_NOFLUSH},
+  {"Performance_schema_rwlock_classes_lost",
+    (char*) &rwlock_class_lost, SHOW_LONG_NOFLUSH},
+  {"Performance_schema_cond_classes_lost",
+    (char*) &cond_class_lost, SHOW_LONG_NOFLUSH},
+  {"Performance_schema_thread_classes_lost",
+    (char*) &thread_class_lost, SHOW_LONG_NOFLUSH},
+  {"Performance_schema_file_classes_lost",
+    (char*) &file_class_lost, SHOW_LONG_NOFLUSH},
+  {"Performance_schema_socket_classes_lost",
+    (char*) &socket_class_lost, SHOW_LONG_NOFLUSH},
+  {"Performance_schema_memory_classes_lost",
+    (char*) &memory_class_lost, SHOW_LONG_NOFLUSH},
+  {"Performance_schema_mutex_instances_lost",
+    (char*) &show_func_mutex_instances_lost, SHOW_FUNC},
+  {"Performance_schema_rwlock_instances_lost",
+    (char*) &global_rwlock_container.m_lost, SHOW_LONG},
+  {"Performance_schema_cond_instances_lost",
+    (char*) &global_cond_container.m_lost, SHOW_LONG},
+  {"Performance_schema_thread_instances_lost",
+    (char*) &global_thread_container.m_lost, SHOW_LONG},
+  {"Performance_schema_file_instances_lost",
+    (char*) &global_file_container.m_lost, SHOW_LONG},
+  {"Performance_schema_file_handles_lost",
+    (char*) &file_handle_lost, SHOW_LONG},
+  {"Performance_schema_socket_instances_lost",
+    (char*) &global_socket_container.m_lost, SHOW_LONG},
+  {"Performance_schema_locker_lost",
+    (char*) &locker_lost, SHOW_LONG},
+  /* table shares, can be flushed */
+  {"Performance_schema_table_instances_lost",
+    (char*) &global_table_share_container.m_lost, SHOW_LONG},
+  /* table handles, can be flushed */
+  {"Performance_schema_table_handles_lost",
+    (char*) &global_table_container.m_lost, SHOW_LONG},
+  /* table lock stats, can be flushed */
+  {"Performance_schema_table_lock_stat_lost",
+    (char*) &global_table_share_lock_container.m_lost, SHOW_LONG},
+  /* table index stats, can be flushed */
+  {"Performance_schema_index_stat_lost",
+    (char*) &global_table_share_index_container.m_lost, SHOW_LONG},
+  {"Performance_schema_hosts_lost",
+    (char*) &global_host_container.m_lost, SHOW_LONG},
+  {"Performance_schema_users_lost",
+    (char*) &global_user_container.m_lost, SHOW_LONG},
+  {"Performance_schema_accounts_lost",
+    (char*) &global_account_container.m_lost, SHOW_LONG},
+  {"Performance_schema_stage_classes_lost",
+    (char*) &stage_class_lost, SHOW_LONG},
+  {"Performance_schema_statement_classes_lost",
+    (char*) &statement_class_lost, SHOW_LONG},
+  {"Performance_schema_digest_lost",
+    (char*) &digest_lost, SHOW_LONG},
+  {"Performance_schema_session_connect_attrs_lost",
+    (char*) &session_connect_attrs_lost, SHOW_LONG},
+  {"Performance_schema_program_lost",
+    (char*) &global_program_container.m_lost, SHOW_LONG},
+  {"Performance_schema_nested_statement_lost",
+    (char*) &nested_statement_lost, SHOW_LONG},
+  {"Performance_schema_prepared_statements_lost",
+    (char*) &global_prepared_stmt_container.m_lost, SHOW_LONG},
+  {"Performance_schema_metadata_lock_lost",
+    (char*) &global_mdl_container.m_lost, SHOW_LONG},
+  {NullS, NullS, SHOW_LONG}
+};
+
+struct st_mysql_storage_engine pfs_storage_engine=
+{ MYSQL_HANDLERTON_INTERFACE_VERSION };
+
+const char* pfs_engine_name= "PERFORMANCE_SCHEMA";
+
+maria_declare_plugin(perfschema)
+{
+  MYSQL_STORAGE_ENGINE_PLUGIN,
+  &pfs_storage_engine,
+  pfs_engine_name,
+  "Marc Alff, Oracle",
+  "Performance Schema",
+  PLUGIN_LICENSE_GPL,
+  pfs_init_func,
+  pfs_done_func,
+  0x0001,
+  pfs_status_vars,
+  NULL,
+  "5.7.31",
+  MariaDB_PLUGIN_MATURITY_STABLE
+}
+maria_declare_plugin_end;
+
+ha_perfschema::ha_perfschema(handlerton *hton, TABLE_SHARE *share)
+  : handler(hton, share), m_table_share(NULL), m_table(NULL)
+{}
+
+ha_perfschema::~ha_perfschema() = default;
+
+int ha_perfschema::open(const char *name, int mode, uint test_if_locked)
+{
+  DBUG_ENTER("ha_perfschema::open");
+
+  m_table_share= find_table_share(table_share->db.str,
+                                  table_share->table_name.str);
+  if (! m_table_share)
+    DBUG_RETURN(HA_ERR_NO_SUCH_TABLE);
+
+  thr_lock_data_init(m_table_share->m_thr_lock_ptr, &m_thr_lock, NULL);
+  ref_length= m_table_share->m_ref_length;
+
+  DBUG_RETURN(0);
+}
+
+int ha_perfschema::close(void)
+{
+  DBUG_ENTER("ha_perfschema::close");
+  m_table_share= NULL;
+  delete m_table;
+  m_table= NULL;
+
+  DBUG_RETURN(0);
+}
+
+int ha_perfschema::write_row(const uchar *buf)
+{
+  int result;
+
+  DBUG_ENTER("ha_perfschema::write_row");
+  if (!PFS_ENABLED())
+    DBUG_RETURN(HA_ERR_WRONG_COMMAND);
+
+  DBUG_ASSERT(m_table_share);
+  result= m_table_share->write_row(table, buf, table->field);
+  DBUG_RETURN(result);
+}
+
+void ha_perfschema::use_hidden_primary_key(void)
+{
+  /*
+    This is also called in case of row based replication,
+    see TABLE::mark_columns_needed_for_update().
+    Add all columns to the read set, but do not touch the write set,
+    as some columns in the SETUP_ tables are not writable.
+  */
+  table->column_bitmaps_set_no_signal(&table->s->all_set, table->write_set);
+}
+
+int ha_perfschema::update_row(const uchar *old_data, const uchar *new_data)
+{
+  DBUG_ENTER("ha_perfschema::update_row");
+  if (!PFS_ENABLED())
+    DBUG_RETURN(HA_ERR_WRONG_COMMAND);
+
+  if (is_executed_by_slave())
+    DBUG_RETURN(0);
+
+  DBUG_ASSERT(m_table);
+  int result= m_table->update_row(table, old_data, new_data, table->field);
+  DBUG_RETURN(result);
+}
+
+int ha_perfschema::delete_row(const uchar *buf)
+{
+  DBUG_ENTER("ha_perfschema::delete_row");
+  if (!PFS_ENABLED())
+    DBUG_RETURN(HA_ERR_WRONG_COMMAND);
+
+  DBUG_ASSERT(m_table);
+  int result= m_table->delete_row(table, buf, table->field);
+  DBUG_RETURN(result);
+}
+
+int ha_perfschema::rnd_init(bool scan)
+{
+  int result;
+  DBUG_ENTER("ha_perfschema::rnd_init");
+
+  assert(m_table_share);
+  assert(m_table_share->m_open_table != NULL);
+
+  stats.records= 0;
+  if (m_table == NULL)
+    m_table= m_table_share->m_open_table();
+  else
+    m_table->reset_position();
+
+  if (m_table != NULL)
+    m_table->rnd_init(scan);
+
+  result= m_table ? 0 : HA_ERR_OUT_OF_MEM;
+  DBUG_RETURN(result);
+}
+
+int ha_perfschema::rnd_end(void)
+{
+  DBUG_ENTER("ha_perfschema::rnd_end");
+  assert(m_table);
+  delete m_table;
+  m_table= NULL;
+  DBUG_RETURN(0);
+}
+
+int ha_perfschema::rnd_next(uchar *buf)
+{
+  DBUG_ENTER("ha_perfschema::rnd_next");
+  if (!PFS_ENABLED())
+  {
+    table->status= STATUS_NOT_FOUND;
+    DBUG_RETURN(HA_ERR_END_OF_FILE);
+  }
+
+  DBUG_ASSERT(m_table);
+
+  int result= m_table->rnd_next();
+  if (result == 0)
+  {
+    result= m_table->read_row(table, buf, table->field);
+    if (result == 0)
+      stats.records++;
+  }
+  table->status= (result ? STATUS_NOT_FOUND : 0);
+  DBUG_RETURN(result);
+}
+
+void ha_perfschema::position(const uchar *record)
+{
+  DBUG_ENTER("ha_perfschema::position");
+
+  assert(m_table);
+  m_table->get_position(ref);
+  DBUG_VOID_RETURN;
+}
+
+int ha_perfschema::rnd_pos(uchar *buf, uchar *pos)
+{
+  DBUG_ENTER("ha_perfschema::rnd_pos");
+  if (!PFS_ENABLED())
+  {
+    table->status= STATUS_NOT_FOUND;
+    DBUG_RETURN(HA_ERR_END_OF_FILE);
+  }
+
+  DBUG_ASSERT(m_table);
+  int result= m_table->rnd_pos(pos);
+  if (result == 0)
+    result= m_table->read_row(table, buf, table->field);
+  table->status= (result ? STATUS_NOT_FOUND : 0);
+  DBUG_RETURN(result);
+}
+
+int ha_perfschema::info(uint flag)
+{
+  DBUG_ENTER("ha_perfschema::info");
+  assert(m_table_share);
+  if (flag & HA_STATUS_VARIABLE)
+    stats.records= m_table_share->get_row_count();
+  if (flag & HA_STATUS_CONST)
+    ref_length= m_table_share->m_ref_length;
+  DBUG_RETURN(0);
+}
+
+int ha_perfschema::delete_all_rows(void)
+{
+  int result;
+
+  DBUG_ENTER("ha_perfschema::delete_all_rows");
+  if (!PFS_ENABLED())
+    DBUG_RETURN(0);
+
+  if (is_executed_by_slave())
+    DBUG_RETURN(0);
+
+  assert(m_table_share);
+  if (m_table_share->m_delete_all_rows)
+    result= m_table_share->m_delete_all_rows();
+  else
+  {
+    result= HA_ERR_WRONG_COMMAND;
+  }
+  DBUG_RETURN(result);
+}
+
+int ha_perfschema::truncate()
+{
+  return delete_all_rows();
+}
+
+THR_LOCK_DATA **ha_perfschema::store_lock(THD *thd,
+                                       THR_LOCK_DATA **to,
+                                       enum thr_lock_type lock_type)
+{
+  if (lock_type != TL_IGNORE && m_thr_lock.type == TL_UNLOCK)
+    m_thr_lock.type= lock_type;
+  *to++= &m_thr_lock;
+  m_thr_lock.m_psi= m_psi;
+  return to;
+}
+
+int ha_perfschema::delete_table(const char *name)
+{
+  DBUG_ENTER("ha_perfschema::delete_table");
+
+  /*
+    The name string looks like:
+    "./performance_schema/processlist"
+
+    Make a copy of it, parse the '/' to
+    isolate the schema and table name.
+  */
+
+  char table_path[FN_REFLEN+1];
+  strncpy(table_path, name, sizeof(table_path));
+  table_path[FN_REFLEN]='\0';
+
+  char *ptr;
+  char *table_name;
+  char *db_name;
+  const PFS_engine_table_share *share;
+
+  /* Start scan from the end. */
+  ptr = strend(table_path) - 1;
+
+  /* Find path separator */
+  while ((ptr >= table_path) && (*ptr != '\\') && (*ptr != '/')) {
+    ptr--;
+  }
+
+  table_name = ptr + 1;
+  *ptr = '\0';
+
+  /* Find path separator */
+  while ((ptr >= table_path) && (*ptr != '\\') && (*ptr != '/')) {
+    ptr--;
+  }
+
+  db_name = ptr + 1;
+
+  share = find_table_share(db_name, table_name);
+  if (share != NULL) {
+    if (share->m_optional) {
+      /*
+        An optional table is deleted,
+        disarm the checked flag so we don't trust it any more.
+      */
+      share->m_state->m_checked = false;
+    }
+  }
+
+  DBUG_RETURN(0);
+}
+
+int ha_perfschema::rename_table(const char * from, const char * to)
+{
+  DBUG_ENTER("ha_perfschema::rename_table ");
+  DBUG_RETURN(HA_ERR_WRONG_COMMAND);
+}
+
+int ha_perfschema::create(const char *name, TABLE *table_arg,
+                          HA_CREATE_INFO *create_info)
+{
+  DBUG_ENTER("ha_perfschema::create");
+  /*
+    This is not a general purpose engine.
+    Failure to CREATE TABLE is the expected result.
+  */
+  DBUG_RETURN(HA_ERR_WRONG_COMMAND);
+}
+
+void ha_perfschema::print_error(int error, myf errflag)
+{
+  switch (error)
+  {
+    case HA_ERR_TABLE_NEEDS_UPGRADE:
+      /*
+        The error message for ER_TABLE_NEEDS_UPGRADE refers to REPAIR table,
+        which does not apply to performance schema tables.
+      */
+      my_error(ER_WRONG_NATIVE_TABLE_STRUCTURE, MYF(0),
+               table_share->db.str, table_share->table_name.str);
+      break;
+    case HA_ERR_WRONG_COMMAND:
+      /*
+        The performance schema is not a general purpose storage engine,
+        some operations are not supported, by design.
+        We do not want to print "Command not supported",
+        which gives the impression that a command implementation is missing,
+        and that the failure should be considered a bug.
+        We print "Invalid performance_schema usage." instead,
+        to emphasise that the operation attempted is not meant to be legal,
+        and that the failure returned is indeed the expected result.
+      */
+      my_error(ER_WRONG_PERFSCHEMA_USAGE, MYF(0));
+      break;
+    default:
+     handler::print_error(error, errflag);
+     break;
+  }
+}
+