DB Layer:

- Make SQL Transactions actual objects used in code. (Thanks to Derex for the idea)
* Uncommitted transactions will be automatically rolled back and cleaned up using ACE_Refcounted_Auto_Ptr, so no need to call Rollback() in the code.
* Prevents recursive transactions and makes developers aware of transactions going on.
* Gets rid of unneccesary overhead iterating over a concurrent map.
- Some cleanups in affected code, including better usage of transaction control in AH / mail related code to prevent data loss.

*** Experimental, use at own risk, recommended to backup your DBs. ***

--HG--
branch : trunk

7 files changed, 149 insertions, 96 deletions

diff --git a/src/server/shared/Database/DatabaseEnv.h b/src/server/shared/Database/DatabaseEnv.h
index a878a358760..d6aa7dc9b41 100644
--- a/src/server/shared/Database/DatabaseEnv.h
+++ b/src/server/shared/Database/DatabaseEnv.h
@@ -30,8 +30,10 @@
 
 #include "DatabaseWorkerPool.h"
 #include "MySQLThreading.h"
+#include "Transaction.h"
 
 typedef DatabaseWorkerPool DatabaseType;
+
 #define _LIKE_           "LIKE"
 #define _TABLE_SIM_      "`"
 #define _CONCAT3_(A,B,C) "CONCAT( " A " , " B " , " C " )"
diff --git a/src/server/shared/Database/DatabaseWorkerPool.cpp b/src/server/shared/Database/DatabaseWorkerPool.cpp
index 538a3535efd..654caf33511 100644
--- a/src/server/shared/Database/DatabaseWorkerPool.cpp
+++ b/src/server/shared/Database/DatabaseWorkerPool.cpp
@@ -16,7 +16,6 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
-#include "DatabaseEnv.h"
 #include "DatabaseWorkerPool.h"
 #include "MySQLConnection.h"
 #include "DatabaseEnv.h"
@@ -183,43 +182,25 @@ QueryResult_AutoPtr DatabaseWorkerPool::PQuery(const char* sql, ...)
     return Query(szQuery);
 }
 
-void DatabaseWorkerPool::BeginTransaction()
+SQLTransaction DatabaseWorkerPool::BeginTransaction()
 {
-    ACE_Guard<ACE_Thread_Mutex> guard(m_transQueues_mtx);
-    ACE_Based::Thread* tranThread = ACE_Based::Thread::current();              // owner of this transaction
-    TransactionQueues::iterator itr = m_tranQueues.find(tranThread);
-    if (itr != m_tranQueues.end() && itr->second != NULL)
-    {
-        itr->second->ForcefulDelete();
-        delete itr->second;
-    }
-    m_tranQueues[tranThread] = new TransactionTask();
-    return;
+    return SQLTransaction(new Transaction);
 }
 
-void DatabaseWorkerPool::RollbackTransaction()
+void DatabaseWorkerPool::CommitTransaction(SQLTransaction transaction)
 {
-    ACE_Guard<ACE_Thread_Mutex> guard(m_transQueues_mtx);
-    ACE_Based::Thread* tranThread = ACE_Based::Thread::current();              // owner of this transaction
-    TransactionQueues::iterator itr = m_tranQueues.find(tranThread);
-    if (itr != m_tranQueues.end() && itr->second != NULL)
+    #ifdef _DEBUG
+    if (transaction->GetSize() == 0)
     {
-        itr->second->ForcefulDelete();
-        delete itr->second;
-        itr->second = NULL;
+        sLog.outError("Transaction contains 0 queries");
+        return;
     }
-}
-
-void DatabaseWorkerPool::CommitTransaction()
-{
-    ACE_Guard<ACE_Thread_Mutex> guard(m_transQueues_mtx);
-    ACE_Based::Thread* tranThread = ACE_Based::Thread::current();              // owner of this transaction
-    TransactionQueues::iterator itr = m_tranQueues.find(tranThread);
-    if (itr != m_tranQueues.end() && itr->second != NULL)
+    if (transaction->GetSize() == 1)
     {
-        Enqueue(itr->second);
-        itr->second = NULL;
+        sLog.outDetail("Warning: Transaction only holds 1 query, consider removing Transaction context in code.");
     }
+    #endif
+    Enqueue(new TransactionTask(transaction));
 }
 
 ACE_Future<QueryResult_AutoPtr> DatabaseWorkerPool::AsyncQuery(const char* sql)
@@ -258,7 +239,7 @@ MySQLConnection* DatabaseWorkerPool::GetConnection()
         ACE_Guard<ACE_Thread_Mutex> guard(m_connectionMap_mtx);
         itr = m_sync_connections.find(ACE_Based::Thread::current());
         if (itr != m_sync_connections.end())
-            return itr->second;
+            conn = itr->second;
     }
     /*! Bundled threads */
     conn = m_bundle_conn;
diff --git a/src/server/shared/Database/DatabaseWorkerPool.h b/src/server/shared/Database/DatabaseWorkerPool.h
index 6443d05b0dd..2a1350888a2 100644
--- a/src/server/shared/Database/DatabaseWorkerPool.h
+++ b/src/server/shared/Database/DatabaseWorkerPool.h
@@ -28,6 +28,7 @@
 #include "QueryResult.h"
 #include "Callback.h"
 #include "MySQLConnection.h"
+#include "Transaction.h"
 
 enum MySQLThreadBundle
 {
@@ -73,9 +74,8 @@ class DatabaseWorkerPool
         ACE_Future<QueryResult_AutoPtr> AsyncPQuery(const char* sql, ...);
         QueryResultHolderFuture DelayQueryHolder(SQLQueryHolder* holder);
         
-        void BeginTransaction();
-        void RollbackTransaction();
-        void CommitTransaction();
+        SQLTransaction BeginTransaction();
+        void CommitTransaction(SQLTransaction transaction);
 
         void escape_string(std::string& str)
         {
@@ -117,8 +117,6 @@ class DatabaseWorkerPool
         MySQLConnection*                m_bundle_conn;       //! Bundled connection (see Database.ThreadBundleMask config)
         AtomicUInt                      m_connections;       //! Counter of MySQL connections; 
         std::string                     m_infoString;        //! Infostring that is passed on to child connections.
-        TransactionQueues               m_tranQueues;        //! Transaction queues from diff. threads
-        ACE_Thread_Mutex                m_transQueues_mtx;   //! To guard m_transQueues
 };
 
 #endif
diff --git a/src/server/shared/Database/SQLOperation.cpp b/src/server/shared/Database/SQLOperation.cpp
index 1cd45a4c0b6..a3eda4b7239 100644
--- a/src/server/shared/Database/SQLOperation.cpp
+++ b/src/server/shared/Database/SQLOperation.cpp
@@ -16,9 +16,9 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
-#include "DatabaseEnv.h"
 #include "SQLOperation.h"
 #include "MySQLConnection.h"
+#include "Log.h"
 
 /*! Basic, ad-hoc queries. */
 BasicStatementTask::BasicStatementTask(const char* sql) :
@@ -53,53 +53,6 @@ bool BasicStatementTask::Execute()
     return m_conn->Execute(m_sql);
 }
 
-/*! Transactions. */
-TransactionTask::TransactionTask()
-{
-}
-
-TransactionTask::~TransactionTask()
-{
-   
-}
-
-void TransactionTask::ForcefulDelete()
-{
-    while (!m_queries.empty())
-    {
-        free((void*)const_cast<char*>(m_queries.front()));
-        m_queries.pop();
-    }
-}
-
-bool TransactionTask::Execute()
-{
-    if (m_queries.empty())
-        return false;
-
-    const char* sql;
-
-    m_conn->BeginTransaction();
-    while (!m_queries.empty())
-    {
-        sql = m_queries.front();
-        if (!m_conn->Execute(sql))
-        {
-            free((void*)const_cast<char*>(sql));
-            m_queries.pop();
-            m_conn->RollbackTransaction();
-            ForcefulDelete();
-            return false;
-        }
-
-        free((void*)const_cast<char*>(sql));
-        m_queries.pop();
-    }
-
-    m_conn->CommitTransaction();
-    return true;
-}
-
 bool SQLQueryHolder::SetQuery(size_t index, const char *sql)
 {
     if (m_queries.size() <= index)
diff --git a/src/server/shared/Database/SQLOperation.h b/src/server/shared/Database/SQLOperation.h
index a8238802e31..0c5fe08d94e 100644
--- a/src/server/shared/Database/SQLOperation.h
+++ b/src/server/shared/Database/SQLOperation.h
@@ -59,19 +59,7 @@ class BasicStatementTask :  public SQLOperation
         QueryResultFuture m_result;
 };
 
-/*! Transactions */
-class TransactionTask : public SQLOperation
-{
-    public:
-        TransactionTask();
-        ~TransactionTask();
-        void ForcefulDelete();
-
-        bool Execute();
 
-    private:
-        std::queue<char*> m_queries;
-};
 
 class SQLQueryHolder
 {
diff --git a/src/server/shared/Database/Transaction.cpp b/src/server/shared/Database/Transaction.cpp
new file mode 100644
index 00000000000..a364728b2d0
--- /dev/null
+++ b/src/server/shared/Database/Transaction.cpp
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2008-2010 Trinity <http://www.trinitycore.org/>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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 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, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "Transaction.h"
+
+void Transaction::Append(const char* sql)
+{
+    m_queries.push(strdup(sql));
+}
+
+void Transaction::PAppend(const char* sql, ...)
+{
+    va_list ap;
+    char szQuery [MAX_QUERY_LEN];
+    va_start(ap, sql);
+    int res = vsnprintf(szQuery, MAX_QUERY_LEN, sql, ap);
+    va_end(ap);
+
+    Append(szQuery);
+}
+
+void Transaction::Cleanup()
+{
+    while (!m_queries.empty())
+    {
+        free((void*)const_cast<char*>(m_queries.front()));
+        m_queries.pop();
+    }
+}
+
+bool TransactionTask::Execute()
+{
+    std::queue<char*>& queries = m_trans->m_queries;
+    if (queries.empty())
+        return false;
+
+    const char* sql;
+
+    m_conn->BeginTransaction();
+    while (!queries.empty())
+    {
+        sql = queries.front();
+        if (!m_conn->Execute(sql))
+        {
+            free((void*)const_cast<char*>(sql));
+            queries.pop();
+            m_conn->RollbackTransaction();
+            return false;
+        }
+
+        free((void*)const_cast<char*>(sql));
+        queries.pop();
+    }
+
+    m_conn->CommitTransaction();
+    return true;
+}
diff --git a/src/server/shared/Database/Transaction.h b/src/server/shared/Database/Transaction.h
new file mode 100644
index 00000000000..e94ca053e32
--- /dev/null
+++ b/src/server/shared/Database/Transaction.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2008-2010 Trinity <http://www.trinitycore.org/>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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 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, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef _TRANSACTION_H
+#define _TRANSACTION_H
+
+/*! Transactions, high level class. */
+class Transaction
+{
+    friend class TransactionTask;
+    public:
+        ~Transaction() { Cleanup(); }
+
+        void Append(const char* sql);
+        void PAppend(const char* sql, ...);
+    
+        size_t GetSize() { return m_queries.size(); }
+
+    protected:
+        void Cleanup();
+        std::queue<char*> m_queries;
+
+    private:
+        bool m_actioned;
+};
+typedef ACE_Refcounted_Auto_Ptr<Transaction, ACE_Null_Mutex> SQLTransaction;
+
+/*! Low level class*/
+class TransactionTask : public SQLOperation
+{
+    friend class DatabaseWorkerPool;
+    friend class DatabaseWorker;
+
+    public:
+        TransactionTask(SQLTransaction trans) : m_trans(trans) {} ;
+        ~TransactionTask(){};
+
+    protected:
+        bool Execute();
+
+        SQLTransaction m_trans;
+};
+
+#endif
\ No newline at end of file