MXS-1810: Create Trx class

The class encapsulates the relevant information of a transaction.

server/modules/routing/readwritesplit/rwsplitsession.hh

@@ -14,13 +14,12 @@
 
 #include "readwritesplit.hh"
 #include "rwbackend.hh"
+#include "trx.hh"
 
 #include <string>
-#include <deque>
 
 #include <maxscale/buffer.hh>
 #include <maxscale/modutil.h>
-#include <maxscale/utils.hh>
 #include <maxscale/queryclassifier.hh>
 
 #define TARGET_IS_MASTER(t)         maxscale::QueryClassifier::target_is_master(t)
@@ -40,9 +39,6 @@ typedef std::list< std::pair<mxs::SRWBackend, uint8_t> > SlaveResponseList;
 /** Map of COM_STMT_EXECUTE targets by internal ID */
 typedef std::tr1::unordered_map<uint32_t, mxs::SRWBackend> ExecMap;
 
-// A log of executed queries, for transaction replay
-typedef std::deque<mxs::Buffer> TrxLog;
-
 /**
  * The client session of a RWSplit instance
  */
@@ -141,8 +137,7 @@ public:
     mxs::QueryClassifier    m_qc; /**< The query classifier. */
     uint64_t                m_retry_duration; /**< Total time spent retrying queries */
     mxs::Buffer             m_current_query; /**< Current query being executed */
-    mxs::SHA1Checksum       m_trx_checksum; /**< Transaction checksum */
-    TrxLog                  m_trx_log; /**< Log of executed queries in the current transaction */
+    Trx                     m_trx; /**< Current transaction */
 
 private:
     RWSplitSession(RWSplit* instance, MXS_SESSION* session,