--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Framework/Messages/IObserver.cpp	Thu Oct 10 14:11:52 2019 +0200
@@ -0,0 +1,93 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2019 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 "IObserver.h"
+
+#include "IMessage.h"
+#include "../StoneException.h"
+
+#include <Core/Logging.h>
+#include <Core/Toolbox.h>
+
+namespace OrthancStone 
+{
+  IObserver::IObserver(MessageBroker& broker)
+    : broker_(broker)
+    , fingerprint_()
+  {
+    // we store the fingerprint_ as a char array to avoid problems when
+    // reading it in a deceased object.
+    // remember this is panic-level code to track zombie object usage
+    std::string fingerprint = Orthanc::Toolbox::GenerateUuid();
+    const char* fingerprintRaw = fingerprint.c_str();
+    memcpy(fingerprint_, fingerprintRaw, 37);
+    broker_.Register(*this);
+  }
+
+
+  IObserver::~IObserver()
+  {
+    try
+    {
+      LOG(TRACE) << "IObserver(" << std::hex << this << std::dec << ")::~IObserver : fingerprint_ == " << fingerprint_;
+      const char* deadMarker = "deadbeef-dead-dead-0000-0000deadbeef";
+      ORTHANC_ASSERT(strlen(deadMarker) == 36);
+      memcpy(fingerprint_, deadMarker, 37);
+      broker_.Unregister(*this);
+    }
+    catch (const Orthanc::OrthancException& e)
+    {
+      if (e.HasDetails())
+      {
+        LOG(ERROR) << "OrthancException in ~IObserver: " << e.What() << " Details: " << e.GetDetails();
+      }
+      else
+      {
+        LOG(ERROR) << "OrthancException in ~IObserver: " << e.What();
+      }
+    }
+    catch (const std::exception& e)
+    {
+      LOG(ERROR) << "std::exception in ~IObserver: " << e.what();
+    }
+    catch (...)
+    {
+      LOG(ERROR) << "Unknown exception in ~IObserver";
+    }
+  }
+
+
+  bool IObserver::DoesFingerprintLookGood() const
+  {
+    for (size_t i = 0; i < 36; ++i) {
+      bool ok = false;
+      if (fingerprint_[i] >= 'a' && fingerprint_[i] <= 'f')
+        ok = true;
+      if (fingerprint_[i] >= '0' && fingerprint_[i] <= '9')
+        ok = true;
+      if (fingerprint_[i] == '-')
+        ok = true;
+      if (!ok)
+        return false;
+    }
+    return fingerprint_[36] == 0;
+  }
+}