Refactor MYSQL_PROXY

driver/CMakeLists.txt

@@ -60,8 +60,8 @@ WHILE(${DRIVER_INDEX} LESS ${DRIVERS_COUNT})
     base_metrics_holder.cc catalog.cc catalog_no_i_s.cc cluster_topology_info.cc
     cluster_aware_hit_metrics_holder.cc cluster_aware_metrics_container.cc
     cluster_aware_metrics.cc cluster_aware_time_metrics_holder.cc
-    connect.cc cursor.cc desc.cc dll.cc driver.cc
-    error.cc execute.cc failover_connection_handler.cc failover_handler.cc
+    connect.cc connection_handler.cc cursor.cc desc.cc dll.cc driver.cc efm_proxy.cc
+    error.cc execute.cc failover_handler.cc
     failover_reader_handler.cc failover_writer_handler.cc handle.cc host_info.cc info.cc
     monitor.cc monitor_connection_context.cc monitor_service.cc monitor_thread_container.cc
     my_prepared_stmt.cc my_stmt.cc mylog.cc mysql_proxy.cc options.cc parse.cc prepare.cc query_parsing.cc
@@ -83,8 +83,8 @@ WHILE(${DRIVER_INDEX} LESS ${DRIVERS_COUNT})
     CONFIGURE_FILE(${CMAKE_SOURCE_DIR}/driver/driver.rc.cmake ${CMAKE_SOURCE_DIR}/driver/driver${CONNECTOR_DRIVER_TYPE_SHORT}.rc @ONLY)
     SET(DRIVER_SRCS ${DRIVER_SRCS} driver${CONNECTOR_DRIVER_TYPE_SHORT}.def driver${CONNECTOR_DRIVER_TYPE_SHORT}.rc  
                                    base_metrics_holder.h catalog.h cluster_aware_hit_metrics_holder.h cluster_aware_metrics_container.h
-                                   cluster_aware_metrics.h cluster_aware_time_metrics_holder.h cluster_topology_info.h
-                                   driver.h error.h failover.h host_info.h monitor.h monitor_connection_context.h monitor_service.h
+                                   cluster_aware_metrics.h cluster_aware_time_metrics_holder.h cluster_topology_info.h connection_handler.h
+                                   driver.h efm_proxy.h error.h failover.h host_info.h monitor.h monitor_connection_context.h monitor_service.h
                                    monitor_thread_container.h mylog.h mysql_proxy.h myutil.h parse.h query_parsing.h topology_service.h
                                    ../MYODBC_MYSQL.h ../MYODBC_CONF.h ../MYODBC_ODBC.h)
   ENDIF(WIN32)

driver/connect.cc

@@ -751,7 +751,7 @@ SQLRETURN DBC::connect(DataSource *dsrc, bool failover_enabled)
     ds_set_strnattr(&dsrc->server8, (SQLCHAR*)host, strlen(host));
     dsrc->port = port;
 
-    Aws::SDKOptions options;
+    //Aws::SDKOptions options;
     //Aws::InitAPI(options); TODO: causing SSL connection error: SSL_CTX_new failed
     //Aws::ShutdownAPI(options);
 
@@ -1056,7 +1056,8 @@ SQLRETURN SQL_API MySQLConnect(SQLHDBC   hdbc,
   if (ds->save_queries && !dbc->log_file) 
     dbc->log_file = init_log_file();
 
-  dbc->mysql_proxy = new MYSQL_PROXY(dbc, ds);
+  dbc->init_proxy_chain(ds);
+  dbc->connection_handler = std::make_shared<CONNECTION_HANDLER>(dbc);
   dbc->fh = new FAILOVER_HANDLER(dbc, ds);
   rc = dbc->fh->init_cluster_info();
   if (!dbc->ds)
@@ -1173,7 +1174,8 @@ SQLRETURN SQL_API MySQLDriverConnect(SQLHDBC hdbc, SQLHWND hwnd,
     if (ds->save_queries && !dbc->log_file) 
       dbc->log_file = init_log_file();
 
-    dbc->mysql_proxy = new MYSQL_PROXY(dbc, ds);
+    dbc->init_proxy_chain(ds);
+    dbc->connection_handler = std::make_shared<CONNECTION_HANDLER>(dbc);
     dbc->fh = new FAILOVER_HANDLER(dbc, ds);
     rc = dbc->fh->init_cluster_info();
     if (rc == SQL_SUCCESS || rc == SQL_SUCCESS_WITH_INFO)
@@ -1352,7 +1354,8 @@ SQLRETURN SQL_API MySQLDriverConnect(SQLHDBC hdbc, SQLHWND hwnd,
   if (ds->save_queries && !dbc->log_file) 
       dbc->log_file = init_log_file();
 
-  dbc->mysql_proxy = new MYSQL_PROXY(dbc, ds);
+  dbc->init_proxy_chain(ds);
+  dbc->connection_handler = std::make_shared<CONNECTION_HANDLER>(dbc);
   dbc->fh = new FAILOVER_HANDLER(dbc, ds);
   rc = dbc->fh->init_cluster_info();
   if (rc != SQL_SUCCESS && rc != SQL_SUCCESS_WITH_INFO)

driver/failover_connection_handler.cc → driver/connection_handler.cc

@@ -28,12 +28,13 @@
 // http://www.gnu.org/licenses/gpl-2.0.html.
 
 /**
-  @file  failover_connection_handler.c
-  @brief Failover connection functions.
+  @file  connection_handler.c
+  @brief connection functions.
 */
 
+#include "connection_handler.h"
 #include "driver.h"
-#include "failover.h"
+#include "mysql_proxy.h"
 
 #include <codecvt>
 #include <locale>
@@ -51,32 +52,36 @@
     }
 #endif
 
-FAILOVER_CONNECTION_HANDLER::FAILOVER_CONNECTION_HANDLER(DBC* dbc) : dbc{dbc} {}
+CONNECTION_HANDLER::CONNECTION_HANDLER(DBC* dbc) : dbc{dbc} {}
 
-FAILOVER_CONNECTION_HANDLER::~FAILOVER_CONNECTION_HANDLER() {}
+CONNECTION_HANDLER::~CONNECTION_HANDLER() = default;
 
-SQLRETURN FAILOVER_CONNECTION_HANDLER::do_connect(DBC* dbc_ptr, DataSource* ds, bool failover_enabled) {
+SQLRETURN CONNECTION_HANDLER::do_connect(DBC* dbc_ptr, DataSource* ds, bool failover_enabled) {
     return dbc_ptr->connect(ds, failover_enabled);
 }
 
-MYSQL_PROXY* FAILOVER_CONNECTION_HANDLER::connect(const std::shared_ptr<HOST_INFO>& host_info) {
+MYSQL_PROXY* CONNECTION_HANDLER::connect(const std::shared_ptr<HOST_INFO>& host_info, DataSource* ds) {
 
-    if (dbc == nullptr || dbc->ds == nullptr || host_info == nullptr) {
+    if (dbc == nullptr || host_info == nullptr) {
         return nullptr;
     }
 
+    DataSource* ds_to_use = ds_new();
+    ds_copy(ds_to_use, ds ? ds : dbc->ds);
+
     const auto new_host = to_sqlwchar_string(host_info->get_host());
 
-    DBC* dbc_clone = clone_dbc(dbc);
-    ds_set_wstrnattr(&dbc_clone->ds->server, (SQLWCHAR*)new_host.c_str(), new_host.size());
+    DBC* dbc_clone = clone_dbc(dbc, ds_to_use);
+    ds_set_wstrnattr(&ds_to_use->server, (SQLWCHAR*)new_host.c_str(), new_host.size());
 
     MYSQL_PROXY* new_connection = nullptr;
     CLEAR_DBC_ERROR(dbc_clone);
-    const SQLRETURN rc = do_connect(dbc_clone, dbc_clone->ds, true);
+    const SQLRETURN rc = do_connect(dbc_clone, ds_to_use, ds_to_use->enable_cluster_failover);
 
     if (rc == SQL_SUCCESS || rc == SQL_SUCCESS_WITH_INFO) {
         new_connection = dbc_clone->mysql_proxy;
         dbc_clone->mysql_proxy = nullptr;
+        // postpone the deletion of ds_to_use/dbc_clone->ds until we are done with new_connection
         dbc_clone->ds = nullptr;
     }
 
@@ -85,7 +90,7 @@ MYSQL_PROXY* FAILOVER_CONNECTION_HANDLER::connect(const std::shared_ptr<HOST_INF
     return new_connection;
 }
 
-void FAILOVER_CONNECTION_HANDLER::update_connection(
+void CONNECTION_HANDLER::update_connection(
     MYSQL_PROXY* new_connection, const std::string& new_host_name) {
 
     if (new_connection->is_connected()) {
@@ -102,7 +107,7 @@ void FAILOVER_CONNECTION_HANDLER::update_connection(
     }
 }
 
-DBC* FAILOVER_CONNECTION_HANDLER::clone_dbc(DBC* source_dbc) {
+DBC* CONNECTION_HANDLER::clone_dbc(DBC* source_dbc, DataSource* ds) {
 
     DBC* dbc_clone = nullptr;
 
@@ -114,11 +119,9 @@ DBC* FAILOVER_CONNECTION_HANDLER::clone_dbc(DBC* source_dbc) {
         status = my_SQLAllocConnect(henv, &hdbc);
         if (status == SQL_SUCCESS || status == SQL_SUCCESS_WITH_INFO) {
             dbc_clone = static_cast<DBC*>(hdbc);
-            dbc_clone->ds = ds_new();
-            ds_copy(dbc_clone->ds, source_dbc->ds);
-            dbc_clone->mysql_proxy = new MYSQL_PROXY(dbc_clone, dbc_clone->ds);
+            dbc_clone->init_proxy_chain(ds);
         } else {
-            const char* err = "Cannot allocate connection handle when cloning DBC in writer failover process";
+            const char* err = "Cannot allocate connection handle when cloning DBC";
             MYLOG_DBC_TRACE(dbc, err);
             throw std::runtime_error(err);
         }

driver/connection_handler.h

@@ -0,0 +1,64 @@
+// Copyright Amazon.com, Inc. 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
+// (GPLv2), as published by the Free Software Foundation, with the
+// following additional permissions:
+//
+// This program is distributed with certain software that is licensed
+// under separate terms, as designated in a particular file or component
+// or in the license documentation. Without limiting your rights under
+// the GPLv2, the authors of this program hereby grant you an additional
+// permission to link the program and your derivative works with the
+// separately licensed software that they have included with the program.
+//
+// Without limiting the foregoing grant of rights under the GPLv2 and
+// additional permission as to separately licensed software, this
+// program is also subject to the Universal FOSS Exception, version 1.0,
+// a copy of which can be found along with its FAQ at
+// http://oss.oracle.com/licenses/universal-foss-exception.
+//
+// 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, see 
+// http://www.gnu.org/licenses/gpl-2.0.html.
+
+#ifndef __CONNECTION_HANDLER_H__
+#define __CONNECTION_HANDLER_H__
+
+#include "host_info.h"
+
+#include <memory>
+
+#ifdef __linux__
+typedef std::u16string sqlwchar_string;
+#else
+typedef std::wstring sqlwchar_string;
+#endif
+
+sqlwchar_string to_sqlwchar_string(const std::string& src);
+
+struct DBC;
+struct DataSource;
+class MYSQL_PROXY;
+typedef short SQLRETURN;
+
+class CONNECTION_HANDLER {
+    public:
+        CONNECTION_HANDLER(DBC* dbc);
+        virtual ~CONNECTION_HANDLER();
+
+        virtual SQLRETURN do_connect(DBC* dbc_ptr, DataSource* ds, bool failover_enabled);
+        virtual MYSQL_PROXY* connect(const std::shared_ptr<HOST_INFO>& host_info, DataSource* ds);
+        void update_connection(MYSQL_PROXY* new_connection, const std::string& new_host_name);
+
+    private:
+        DBC* dbc;
+        DBC* clone_dbc(DBC* source_dbc, DataSource* ds);
+};
+
+#endif /* __CONNECTION_HANDLER_H__ */

driver/driver.h

@@ -41,9 +41,11 @@
 #include "../MYODBC_MYSQL.h"
 #include "../MYODBC_CONF.h"
 #include "../MYODBC_ODBC.h"
-#include "util/installer.h"
+#include "connection_handler.h"
+#include "efm_proxy.h"
 #include "failover.h"
 #include "mysql_proxy.h"
+#include "util/installer.h"
 
 /* Disable _attribute__ on non-gcc compilers. */
 #if !defined(__attribute__) && !defined(__GNUC__)
@@ -643,6 +645,7 @@ struct DBC
   fido_callback_func fido_callback = nullptr;
 
   FAILOVER_HANDLER *fh = nullptr; /* Failover handler */
+  std::shared_ptr<CONNECTION_HANDLER> connection_handler = nullptr;
 
   DBC(ENV *p_env);
   void free_explicit_descriptors();
@@ -654,6 +657,7 @@ struct DBC
   SQLRETURN connect(DataSource *dsrc, bool failover_enabled);
   void execute_prep_stmt(MYSQL_STMT *pstmt, std::string &query,
     MYSQL_BIND *param_bind, MYSQL_BIND *result_bind);
+  void init_proxy_chain(DataSource *dsrc);
 
   inline bool transactions_supported() {
     return mysql_proxy->get_server_capabilities() & CLIENT_TRANSACTIONS;