--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Framework/Common/ImplicitTransaction.cpp	Thu Jul 12 10:44:17 2018 +0200
@@ -0,0 +1,150 @@
+/**
+ * Orthanc - A Lightweight, RESTful DICOM Store
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2018 Osimis S.A., Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Affero General Public License
+ * as published by the Free Software Foundation, either version 3 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
+ * Affero General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+#include "ImplicitTransaction.h"
+
+#include <Core/Logging.h>
+#include <Core/OrthancException.h>
+
+#include <memory>
+
+namespace OrthancDatabases
+{
+  ImplicitTransaction::ImplicitTransaction() :
+    state_(State_Ready),
+    readOnly_(true)
+  {
+  }
+
+  
+  ImplicitTransaction::~ImplicitTransaction()
+  {
+    switch (state_)
+    {
+      case State_Committed:
+      case State_Ready:
+        break;
+
+      case State_Executed:
+        LOG(ERROR) << "An implicit transaction has not been committed";
+        break;
+
+      default:
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError);
+    }
+  }
+
+  
+  void ImplicitTransaction::Rollback()
+  {
+    LOG(ERROR) << "Cannot rollback an implicit transaction";
+    throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls);
+  }
+
+  
+  void ImplicitTransaction::Commit()
+  {
+    switch (state_)
+    {
+      case State_Ready:
+        LOG(ERROR) << "Cannot commit an implicit transaction that has not been executed yet";
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls);
+
+      case State_Executed:
+        state_ = State_Committed;
+        break;
+
+      case State_Committed:
+        LOG(ERROR) << "Cannot commit twice an implicit transaction";
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls);
+
+      default:
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError);          
+    }
+  }
+
+
+  void ImplicitTransaction::CheckStateForExecution()
+  {
+    switch (state_)
+    {
+      case State_Ready:
+        // OK
+        break;
+
+      case State_Executed:
+#if defined(NDEBUG)
+        // Release build. Ignore such errors.
+        LOG(INFO) << "Cannot execute more than one statement in an implicit transaction";
+        break;        
+#else
+        /**
+         * Debug build. This allows to detect errors wrt. the handling
+         * of transactions in the Orthanc core.
+         *
+         * In Orthanc <= 1.3.2: problems in "/changes" (a transaction
+         * was missing because of GetPublicId()).
+         **/
+        LOG(ERROR) << "Cannot execute more than one statement in an implicit transaction";
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls);
+#endif
+
+      case State_Committed:
+        LOG(ERROR) << "Cannot commit twice an implicit transaction";
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls);
+
+      default:
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError);          
+    }
+  }
+
+
+  IResult* ImplicitTransaction::Execute(IPrecompiledStatement& statement,
+                                        const Dictionary& parameters)
+  {
+    CheckStateForExecution();    
+    std::auto_ptr<IResult> result(ExecuteInternal(statement, parameters));
+
+    if (!statement.IsReadOnly())
+    {
+      readOnly_ = false;
+    }
+
+    state_ = State_Executed;
+    return result.release();
+  }
+  
+
+  void ImplicitTransaction::ExecuteWithoutResult(IPrecompiledStatement& statement,
+                                                 const Dictionary& parameters)
+  {
+    CheckStateForExecution();    
+    ExecuteWithoutResultInternal(statement, parameters);
+
+    if (!statement.IsReadOnly())
+    {
+      readOnly_ = false;
+    }
+    
+    state_ = State_Executed;
+  }
+}
+