MySQL 源码导读 5.7

mysql 主要脉络 (看c/c++ 建议使用QT)

文件 函数1.sql->mysqld.cc(这是整个MySQL的入口) mysqld_socket_acceptor->connection_event_loop();2.sql/conn_handler->connection_handler_manager.ccm_connection_handler->add_connection(channel_info)3.sql/conn_handler->connection_handler_per_thread.cc  error= mysql_thread_create(key_thread_one_connection, &id,
                             &connection_attrib,
                             handle_connection,
                             (void*) channel_info);4.sql->sql_parse.cc do_command(thd)5.sql->sql_parse.cc return_value= dispatch_command(thd, &com_data, command);6.sql->sql_parse.cc mysql_parse(thd, &parser_state);7.sql->sql_parse.cc error= mysql_execute_command(thd, true);8.sql->sql_parse.cc  res= execute_sqlcom_select(thd, all_tables);9.sql->sql_parse.cc  res= handle_query(thd, lex, result, 0, 0); select->join->exec();10.sql->sql_select.cc  select->join->exec();

 

extern "C" void *handle_connection(void *arg){      ...    {      while (thd_connection_alive(thd))      {        if (do_command(thd))          break;      }      end_connection(thd);    }    ....}

bool dispatch_command(THD *thd, const COM_DATA *com_data,enum enum_server_command command){    ...  switch (command) {  case COM_INIT_DB:  {  ...  case COM_QUERY:  {    DBUG_ASSERT(thd->m_digest == NULL);    thd->m_digest= & thd->m_digest_state;    thd->m_digest->reset(thd->m_token_array, max_digest_length);    if (alloc_query(thd, com_data->com_query.query,                    com_data->com_query.length))      break;// fatal error is set    MYSQL_QUERY_START(const_cast<char*>(thd->query().str), thd->thread_id(),                      (char *) (thd->db().str ? thd->db().str : ""),                      (char *) thd->security_context()->priv_user().str,                      (char *) thd->security_context()->host_or_ip().str);    const char *packet_end= thd->query().str + thd->query().length;    if (opt_general_log_raw)      query_logger.general_log_write(thd, command, thd->query().str,                                     thd->query().length);    DBUG_PRINT("query",("%-.4096s", thd->query().str));#if defined(ENABLED_PROFILING)    thd->profiling.set_query_source(thd->query().str, thd->query().length);#endif    MYSQL_SET_STATEMENT_TEXT(thd->m_statement_psi, thd->query().str,                             thd->query().length);    Parser_state parser_state;    if (parser_state.init(thd, thd->query().str, thd->query().length))      break;    mysql_parse(thd, &parser_state);    while (!thd->killed && (parser_state.m_lip.found_semicolon != NULL) &&           ! thd->is_error())    {      /*        Multiple queries exits, execute them individually      */      const char *beginning_of_next_stmt= parser_state.m_lip.found_semicolon;      /* Finalize server status flags after executing a statement. */      thd->update_server_status();      thd->send_statement_status();      query_cache.end_of_result(thd);#ifndef EMBEDDED_LIBRARY      mysql_audit_general(thd, MYSQL_AUDIT_GENERAL_STATUS,                          thd->get_stmt_da()->is_error() ?                          thd->get_stmt_da()->mysql_errno() : 0,                          command_name[command].str);#endif      size_t length= static_cast<size_t>(packet_end - beginning_of_next_stmt);      log_slow_statement(thd);      /* Remove garbage at start of query */      while (length > 0 && my_isspace(thd->charset(), *beginning_of_next_stmt))      {        beginning_of_next_stmt++;        length--;      }/* PSI end */      MYSQL_END_STATEMENT(thd->m_statement_psi, thd->get_stmt_da());      thd->m_statement_psi= NULL;      thd->m_digest= NULL;/* DTRACE end */      if (MYSQL_QUERY_DONE_ENABLED())      {        MYSQL_QUERY_DONE(thd->is_error());      }/* SHOW PROFILE end */#if defined(ENABLED_PROFILING)      thd->profiling.finish_current_query();#endif/* SHOW PROFILE begin */#if defined(ENABLED_PROFILING)      thd->profiling.start_new_query("continuing");      thd->profiling.set_query_source(beginning_of_next_stmt, length);#endif/* DTRACE begin */      MYSQL_QUERY_START(const_cast<char*>(beginning_of_next_stmt),                        thd->thread_id(),                        (char *) (thd->db().str ? thd->db().str : ""),                        (char *) thd->security_context()->priv_user().str,                        (char *) thd->security_context()->host_or_ip().str);/* PSI begin */      thd->m_digest= & thd->m_digest_state;      thd->m_statement_psi= MYSQL_START_STATEMENT(&thd->m_statement_state,                                          com_statement_info[command].m_key,                                          thd->db().str, thd->db().length,                                          thd->charset(), NULL);      THD_STAGE_INFO(thd, stage_starting);      MYSQL_SET_STATEMENT_TEXT(thd->m_statement_psi, beginning_of_next_stmt, length);      thd->set_query(beginning_of_next_stmt, length);      thd->set_query_id(next_query_id());      /*        Count each statement from the client.      */      thd->status_var.questions++;      thd->set_time(); /* Reset the query start time. */      parser_state.reset(beginning_of_next_stmt, length);      /* TODO: set thd->lex->sql_command to SQLCOM_END here */      mysql_parse(thd, &parser_state);    }    /* Need to set error to true for graceful shutdown */    if((thd->lex->sql_command == SQLCOM_SHUTDOWN) && (thd->get_stmt_da()->is_ok()))      error= TRUE;    DBUG_PRINT("info",("query ready"));    break;  }    ...  thd->send_statement_status(); //网络返回  thd->rpl_thd_ctx.session_gtids_ctx().notify_after_response_packet(thd);  query_cache.end_of_result(thd);  ...}