Merge lp:~vlad-lesin/percona-playback/session_init_query into lp:percona-playback

[Vlad Lesin]

--session-init-query option is added. It allows to execute some query just after connection is established. This can be used for example to init some session variables.

This feature can not be tested with current testing system. That's why the test is absent.

[Stewart Smith (stewart)]

review: Approve

=== modified file 'percona_playback/db_thread.cc'
--- percona_playback/db_thread.cc	2012-06-22 06:20:44 +0000
+++ percona_playback/db_thread.cc	2012-11-14 22:02:21 +0000
@@ -16,14 +16,28 @@
 #include "config.h"
 
 #include <percona_playback/db_thread.h>
+#include "percona_playback/query_result.h"
 
 #include <assert.h>
 
 #include <boost/bind.hpp>
 
+extern std::string g_session_init_query;
+
+void DBThread::connect_and_init_session()
+{
+  connect();
+  if (!g_session_init_query.empty())
+  {
+    QueryResult r;
+    QueryResult er;
+    execute_query(g_session_init_query, &r, er);
+  }
+}
+
 void DBThread::run()
 {
-  connect();
+  connect_and_init_session();
 
   QueryEntryPtr query;
   while (true)
@@ -36,7 +50,7 @@
     if (query->is_quit())
     {
       disconnect();
-      connect();
+      connect_and_init_session();
       continue;
     }
 
 
=== modified file 'percona_playback/db_thread.h'
--- percona_playback/db_thread.h	2012-07-04 10:06:05 +0000
+++ percona_playback/db_thread.h	2012-11-14 22:02:21 +0000
@@ -72,6 +72,8 @@
     thread.join();
   }
 
+  void connect_and_init_session();
+
   virtual void connect()= 0;
 
   virtual void disconnect()= 0;
 
=== modified file 'percona_playback/percona_playback.cc'
--- percona_playback/percona_playback.cc	2012-07-05 07:37:39 +0000
+++ percona_playback/percona_playback.cc	2012-11-14 22:02:21 +0000
@@ -41,6 +41,7 @@
 percona_playback::DBClientPlugin *g_dbclient_plugin= NULL;
 percona_playback::InputPlugin *g_input_plugin= NULL;
 unsigned int g_db_thread_queue_depth;
+std::string g_session_init_query;
 
 using namespace percona_playback;
 
@@ -155,6 +156,9 @@
      _("Queue depth for DB executor (thread). The larger this number the"
      " greater the played-back workload can deviate from the original workload"
      " as some connections may be up to queue-depth behind. (default 1)"))
+    ("session-init-query",
+     po::value<std::string>()->default_value(""),
+     _("This query will be executed just after each connect to db"))
     ;
 
   std::string basic_usage;