--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancStone/Sources/Loaders/DicomResourcesLoader.cpp	Tue Jul 07 16:21:02 2020 +0200
@@ -0,0 +1,910 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2020 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 "DicomResourcesLoader.h"
+
+#if !defined(ORTHANC_ENABLE_DCMTK)
+#  error The macro ORTHANC_ENABLE_DCMTK must be defined
+#endif
+
+#if ORTHANC_ENABLE_DCMTK == 1
+#  include "../Oracle/ParseDicomFromFileCommand.h"
+#  include <DicomParsing/ParsedDicomDir.h>
+#  include <DicomParsing/ParsedDicomFile.h>
+#endif
+
+#include <boost/filesystem/path.hpp>
+
+namespace OrthancStone
+{
+  static std::string GetUri(Orthanc::ResourceType level)
+  {
+    switch (level)
+    {
+      case Orthanc::ResourceType_Patient:
+        return "patients";
+        
+      case Orthanc::ResourceType_Study:
+        return "studies";
+        
+      case Orthanc::ResourceType_Series:
+        return "series";
+        
+      case Orthanc::ResourceType_Instance:
+        return "instances";
+
+      default:
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_ParameterOutOfRange);
+    }
+  }
+
+
+  class DicomResourcesLoader::Handler : public Orthanc::IDynamicObject
+  {
+  private:
+    boost::shared_ptr<DicomResourcesLoader>     loader_;
+    boost::shared_ptr<LoadedDicomResources>     target_;
+    int                                         priority_;
+    DicomSource                                 source_;
+    boost::shared_ptr<Orthanc::IDynamicObject>  userPayload_;
+
+  public:
+    Handler(boost::shared_ptr<DicomResourcesLoader> loader,
+            boost::shared_ptr<LoadedDicomResources> target,
+            int priority,
+            const DicomSource& source,
+            boost::shared_ptr<Orthanc::IDynamicObject> userPayload) :
+      loader_(loader),
+      target_(target),
+      priority_(priority),
+      source_(source),
+      userPayload_(userPayload)
+    {
+      if (!loader ||
+          !target)
+      {
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_NullPointer);
+      }
+    }
+      
+    virtual ~Handler()
+    {
+    }
+
+    void BroadcastSuccess()
+    {
+      SuccessMessage message(*loader_, target_, priority_, source_, userPayload_.get());
+      loader_->BroadcastMessage(message);
+    }
+
+    boost::shared_ptr<DicomResourcesLoader> GetLoader()
+    {
+      assert(loader_);
+      return loader_;
+    }
+
+    boost::shared_ptr<LoadedDicomResources> GetTarget()
+    {
+      assert(target_);
+      return target_;
+    }
+
+    int GetPriority() const
+    {
+      return priority_;
+    }
+
+    const DicomSource& GetSource() const
+    {
+      return source_;
+    }
+
+    const boost::shared_ptr<Orthanc::IDynamicObject> GetUserPayload() const
+    {
+      return userPayload_;
+    }
+  };
+
+
+  class DicomResourcesLoader::StringHandler : public DicomResourcesLoader::Handler
+  {
+  public:
+    StringHandler(boost::shared_ptr<DicomResourcesLoader> loader,
+                  boost::shared_ptr<LoadedDicomResources> target,
+                  int priority,
+                  const DicomSource& source,
+                  boost::shared_ptr<Orthanc::IDynamicObject> userPayload) :
+      Handler(loader, target, priority, source, userPayload)
+    {
+    }
+
+    virtual void HandleJson(const Json::Value& body) = 0;
+      
+    virtual void HandleString(const std::string& body)
+    {
+      Json::Reader reader;
+      Json::Value value;
+      if (reader.parse(body, value))
+      {
+        HandleJson(value);
+      }
+      else
+      {
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_NetworkProtocol);
+      }
+    }
+  };
+
+
+  class DicomResourcesLoader::DicomWebHandler : public StringHandler
+  {
+  public:
+    DicomWebHandler(boost::shared_ptr<DicomResourcesLoader> loader,
+                    boost::shared_ptr<LoadedDicomResources> target,
+                    int priority,
+                    const DicomSource& source,
+                    boost::shared_ptr<Orthanc::IDynamicObject> userPayload) :
+      StringHandler(loader, target, priority, source, userPayload)
+    {
+    }
+
+    virtual void HandleJson(const Json::Value& body)
+    {
+      GetTarget()->AddFromDicomWeb(body);
+      BroadcastSuccess();
+    }
+  };
+
+
+  class DicomResourcesLoader::OrthancHandler : public StringHandler
+  {
+  private:
+    boost::shared_ptr<unsigned int>  remainingCommands_;
+
+  protected:
+    void CloseCommand()
+    {
+      assert(remainingCommands_);
+        
+      if (*remainingCommands_ == 0)
+      {
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls);
+      }
+
+      (*remainingCommands_) --;
+
+      if (*remainingCommands_ == 0)
+      {
+        BroadcastSuccess();
+      }
+    }
+      
+  public:
+    OrthancHandler(boost::shared_ptr<DicomResourcesLoader> loader,
+                   boost::shared_ptr<LoadedDicomResources> target,
+                   int priority,
+                   const DicomSource& source,
+                   boost::shared_ptr<unsigned int> remainingCommands,
+                   boost::shared_ptr<Orthanc::IDynamicObject> userPayload) :
+      StringHandler(loader, target, priority, source, userPayload),
+      remainingCommands_(remainingCommands)
+    {
+      if (!remainingCommands)
+      {
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_NullPointer);
+      }
+
+      (*remainingCommands) ++;
+    }
+
+    boost::shared_ptr<unsigned int> GetRemainingCommands()
+    {
+      assert(remainingCommands_);
+      return remainingCommands_;
+    }
+  };
+
+    
+  class DicomResourcesLoader::OrthancInstanceTagsHandler : public OrthancHandler
+  {
+  public:
+    OrthancInstanceTagsHandler(boost::shared_ptr<DicomResourcesLoader> loader,
+                               boost::shared_ptr<LoadedDicomResources> target,
+                               int priority,
+                               const DicomSource& source,
+                               boost::shared_ptr<unsigned int> remainingCommands,
+                               boost::shared_ptr<Orthanc::IDynamicObject> userPayload) :
+      OrthancHandler(loader, target, priority, source, remainingCommands, userPayload)
+    {
+    }
+
+    virtual void HandleJson(const Json::Value& body)
+    {
+      GetTarget()->AddFromOrthanc(body);
+      CloseCommand();
+    }
+  };
+
+    
+  class DicomResourcesLoader::OrthancOneChildInstanceHandler : public OrthancHandler
+  {
+  public:
+    OrthancOneChildInstanceHandler(boost::shared_ptr<DicomResourcesLoader> loader,
+                                   boost::shared_ptr<LoadedDicomResources> target,
+                                   int  priority,
+                                   const DicomSource& source,
+                                   boost::shared_ptr<unsigned int> remainingCommands,
+                                   boost::shared_ptr<Orthanc::IDynamicObject> userPayload) :
+      OrthancHandler(loader, target, priority, source, remainingCommands, userPayload)
+    {
+    }
+
+    virtual void HandleJson(const Json::Value& body)
+    {
+      static const char* const ID = "ID";
+      
+      if (body.type() == Json::arrayValue)
+      {
+        if (body.size() > 0)
+        {
+          if (body[0].type() == Json::objectValue &&
+              body[0].isMember(ID) &&
+              body[0][ID].type() == Json::stringValue)
+          {
+            GetLoader()->ScheduleLoadOrthancInstanceTags
+              (GetTarget(), GetPriority(), GetSource(), body[0][ID].asString(), GetRemainingCommands(), GetUserPayload());
+            CloseCommand();
+          }
+          else
+          {
+            throw Orthanc::OrthancException(Orthanc::ErrorCode_NetworkProtocol);
+          }
+        }
+      }
+      else
+      {
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_NetworkProtocol);
+      }
+    }
+  };
+
+
+  class DicomResourcesLoader::OrthancAllChildrenInstancesHandler : public OrthancHandler
+  {
+  private:
+    Orthanc::ResourceType  bottomLevel_;
+
+  public:
+    OrthancAllChildrenInstancesHandler(boost::shared_ptr<DicomResourcesLoader> loader,
+                                       boost::shared_ptr<LoadedDicomResources> target,
+                                       int  priority,
+                                       const DicomSource& source,
+                                       boost::shared_ptr<unsigned int> remainingCommands,
+                                       Orthanc::ResourceType bottomLevel,
+                                       boost::shared_ptr<Orthanc::IDynamicObject> userPayload) :
+      OrthancHandler(loader, target, priority, source, remainingCommands, userPayload),
+      bottomLevel_(bottomLevel)
+    {
+    }
+
+    virtual void HandleJson(const Json::Value& body)
+    {
+      static const char* const ID = "ID";
+      static const char* const INSTANCES = "Instances";
+
+      if (body.type() == Json::arrayValue)
+      {
+        for (Json::Value::ArrayIndex i = 0; i < body.size(); i++)
+        {
+          switch (bottomLevel_)
+          {
+            case Orthanc::ResourceType_Patient:
+            case Orthanc::ResourceType_Study:
+              if (body[i].type() == Json::objectValue &&
+                  body[i].isMember(ID) &&
+                  body[i][ID].type() == Json::stringValue)
+              {
+                GetLoader()->ScheduleLoadOrthancOneChildInstance
+                  (GetTarget(), GetPriority(), GetSource(), bottomLevel_,
+                   body[i][ID].asString(), GetRemainingCommands(), GetUserPayload());
+              }
+              else
+              {
+                throw Orthanc::OrthancException(Orthanc::ErrorCode_NetworkProtocol);
+              }
+              
+              break;
+            
+            case Orthanc::ResourceType_Series:
+              // At the series level, avoid a call to
+              // "/series/.../instances", as we already have this
+              // information in the JSON
+              if (body[i].type() == Json::objectValue &&
+                  body[i].isMember(INSTANCES) &&
+                  body[i][INSTANCES].type() == Json::arrayValue)
+              {
+                if (body[i][INSTANCES].size() > 0)
+                {
+                  if (body[i][INSTANCES][0].type() == Json::stringValue)
+                  {
+                    GetLoader()->ScheduleLoadOrthancInstanceTags
+                      (GetTarget(), GetPriority(), GetSource(),
+                       body[i][INSTANCES][0].asString(), GetRemainingCommands(), GetUserPayload());
+                  }
+                  else
+                  {
+                    throw Orthanc::OrthancException(Orthanc::ErrorCode_NetworkProtocol);
+                  }
+                }
+              }
+
+              break;
+
+            case Orthanc::ResourceType_Instance:
+              if (body[i].type() == Json::objectValue &&
+                  body[i].isMember(ID) &&
+                  body[i][ID].type() == Json::stringValue)
+              {
+                GetLoader()->ScheduleLoadOrthancInstanceTags
+                  (GetTarget(), GetPriority(), GetSource(),
+                   body[i][ID].asString(), GetRemainingCommands(), GetUserPayload());
+              }
+              else
+              {
+                throw Orthanc::OrthancException(Orthanc::ErrorCode_NetworkProtocol);
+              }
+
+              break;
+
+            default:
+              throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError);
+          }
+        }
+      }
+      
+      CloseCommand();
+    }
+  };
+
+
+#if ORTHANC_ENABLE_DCMTK == 1
+  static void ExploreDicomDir(OrthancStone::LoadedDicomResources& instances,
+                              const Orthanc::ParsedDicomDir& dicomDir,
+                              Orthanc::ResourceType level,
+                              size_t index,
+                              const Orthanc::DicomMap& parent)
+  {
+    std::string expectedType;
+
+    switch (level)
+    {
+      case Orthanc::ResourceType_Patient:
+        expectedType = "PATIENT";
+        break;
+
+      case Orthanc::ResourceType_Study:
+        expectedType = "STUDY";
+        break;
+
+      case Orthanc::ResourceType_Series:
+        expectedType = "SERIES";
+        break;
+
+      case Orthanc::ResourceType_Instance:
+        expectedType = "IMAGE";
+        break;
+
+      default:
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_ParameterOutOfRange);
+    }
+
+    for (;;)
+    {
+      std::unique_ptr<Orthanc::DicomMap> current(dicomDir.GetItem(index).Clone());
+      current->RemoveBinaryTags();
+      current->Merge(parent);
+
+      std::string type;
+      if (!current->LookupStringValue(type, Orthanc::DICOM_TAG_DIRECTORY_RECORD_TYPE, false))
+      {
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_BadFileFormat);
+      }
+
+      if (type == expectedType)
+      {
+        if (level == Orthanc::ResourceType_Instance)
+        {
+          instances.AddResource(*current);
+        }
+        else
+        {
+          size_t lower;
+          if (dicomDir.LookupLower(lower, index))
+          {
+            ExploreDicomDir(instances, dicomDir, Orthanc::GetChildResourceType(level), lower, *current);
+          }
+        }
+      }
+
+      size_t next;
+      if (dicomDir.LookupNext(next, index))
+      {
+        index = next;
+      }
+      else
+      {
+        return;
+      }
+    }
+  }
+#endif
+
+
+#if ORTHANC_ENABLE_DCMTK == 1
+  void DicomResourcesLoader::GetDicomDirInstances(LoadedDicomResources& target,
+                                                  const Orthanc::ParsedDicomDir& dicomDir)
+  {
+    Orthanc::DicomMap parent;
+    ExploreDicomDir(target, dicomDir, Orthanc::ResourceType_Patient, 0, parent);
+  }
+#endif
+
+
+#if ORTHANC_ENABLE_DCMTK == 1
+  class DicomResourcesLoader::DicomDirHandler : public StringHandler
+  {
+  public:
+    DicomDirHandler(boost::shared_ptr<DicomResourcesLoader> loader,
+                    boost::shared_ptr<LoadedDicomResources> target,
+                    int priority,
+                    const DicomSource& source,
+                    boost::shared_ptr<Orthanc::IDynamicObject> userPayload) :
+      StringHandler(loader, target, priority, source, userPayload)
+    {
+    }
+
+    virtual void HandleJson(const Json::Value& body)
+    {
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError);
+    }
+      
+    virtual void HandleString(const std::string& body)
+    {
+      Orthanc::ParsedDicomDir dicomDir(body);
+      GetDicomDirInstances(*GetTarget(), dicomDir);
+      BroadcastSuccess();
+    }
+  };
+#endif
+  
+    
+  void DicomResourcesLoader::Handle(const HttpCommand::SuccessMessage& message)
+  {
+    if (message.GetOrigin().HasPayload())
+    {
+      dynamic_cast<StringHandler&>(message.GetOrigin().GetPayload()).HandleString(message.GetAnswer());
+    }
+  }
+
+
+  void DicomResourcesLoader::Handle(const OrthancRestApiCommand::SuccessMessage& message)
+  {
+    if (message.GetOrigin().HasPayload())
+    {
+      dynamic_cast<StringHandler&>(message.GetOrigin().GetPayload()).HandleString(message.GetAnswer());
+    }
+  }
+
+
+  void DicomResourcesLoader::Handle(const ReadFileCommand::SuccessMessage& message)
+  {
+    if (message.GetOrigin().HasPayload())
+    {
+      dynamic_cast<StringHandler&>(message.GetOrigin().GetPayload()).HandleString(message.GetContent());
+    }
+  }
+
+
+#if ORTHANC_ENABLE_DCMTK == 1
+  void DicomResourcesLoader::Handle(const ParseDicomSuccessMessage& message)
+  {
+    if (message.GetOrigin().HasPayload())
+    {
+      Handler& handler = dynamic_cast<Handler&>(message.GetOrigin().GetPayload());
+
+      std::set<Orthanc::DicomTag> ignoreTagLength;
+      ignoreTagLength.insert(Orthanc::DICOM_TAG_GRID_FRAME_OFFSET_VECTOR);  // Needed for RT-DOSE
+
+      Orthanc::DicomMap summary;
+      message.GetDicom().ExtractDicomSummary(summary, ignoreTagLength);
+      handler.GetTarget()->AddResource(summary);
+
+      handler.BroadcastSuccess();
+    }
+  }
+#endif
+
+
+  void DicomResourcesLoader::Handle(const OracleCommandExceptionMessage& message)
+  {
+    // TODO
+    LOG(ERROR) << "Exception: " << message.GetException().What();
+  }
+    
+
+  void DicomResourcesLoader::ScheduleLoadOrthancInstanceTags(boost::shared_ptr<LoadedDicomResources> target,
+                                                             int priority,
+                                                             const DicomSource& source,
+                                                             const std::string& instanceId,
+                                                             boost::shared_ptr<unsigned int> remainingCommands,
+                                                             boost::shared_ptr<Orthanc::IDynamicObject> userPayload)
+  {
+    std::unique_ptr<OrthancRestApiCommand> command(new OrthancRestApiCommand);
+    command->SetUri("/instances/" + instanceId + "/tags");
+    command->AcquirePayload(new OrthancInstanceTagsHandler(shared_from_this(), target, priority,
+                                                           source, remainingCommands, userPayload));
+
+    {
+      std::unique_ptr<ILoadersContext::ILock> lock(context_.Lock());
+      lock->Schedule(GetSharedObserver(), priority, command.release());
+    }
+  }
+
+
+  void DicomResourcesLoader::ScheduleLoadOrthancOneChildInstance(boost::shared_ptr<LoadedDicomResources> target,
+                                                                 int priority,
+                                                                 const DicomSource& source,
+                                                                 Orthanc::ResourceType level,
+                                                                 const std::string& id,
+                                                                 boost::shared_ptr<unsigned int> remainingCommands,
+                                                                 boost::shared_ptr<Orthanc::IDynamicObject> userPayload)
+  {
+    std::unique_ptr<OrthancRestApiCommand> command(new OrthancRestApiCommand);
+    command->SetUri("/" + GetUri(level) + "/" + id + "/instances");
+    command->AcquirePayload(new OrthancOneChildInstanceHandler(shared_from_this(), target, priority,
+                                                               source, remainingCommands, userPayload));
+
+    {
+      std::unique_ptr<ILoadersContext::ILock> lock(context_.Lock());
+      lock->Schedule(GetSharedObserver(), priority, command.release());
+    }
+  }
+    
+    
+
+  const Orthanc::IDynamicObject& DicomResourcesLoader::SuccessMessage::GetUserPayload() const
+  {
+    if (userPayload_ == NULL)
+    {
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls);
+    }
+    else
+    {
+      return *userPayload_;
+    }
+  }
+
+
+  boost::shared_ptr<DicomResourcesLoader> DicomResourcesLoader::Create(ILoadersContext::ILock& stone)
+  {
+    boost::shared_ptr<DicomResourcesLoader> result(new DicomResourcesLoader(stone.GetContext()));
+    result->Register<HttpCommand::SuccessMessage>(stone.GetOracleObservable(), &DicomResourcesLoader::Handle);
+    result->Register<OracleCommandExceptionMessage>(stone.GetOracleObservable(), &DicomResourcesLoader::Handle);
+    result->Register<OrthancRestApiCommand::SuccessMessage>(stone.GetOracleObservable(), &DicomResourcesLoader::Handle);
+    result->Register<ReadFileCommand::SuccessMessage>(stone.GetOracleObservable(), &DicomResourcesLoader::Handle);
+
+#if ORTHANC_ENABLE_DCMTK == 1
+    result->Register<ParseDicomSuccessMessage>(stone.GetOracleObservable(), &DicomResourcesLoader::Handle);
+#endif
+    
+    return result;
+  }
+
+
+  static void SetIncludeTags(std::map<std::string, std::string>& arguments,
+                             const std::set<Orthanc::DicomTag>& includeTags)
+  {
+    if (!includeTags.empty())
+    {
+      std::string s;
+      bool first = true;
+
+      for (std::set<Orthanc::DicomTag>::const_iterator
+             it = includeTags.begin(); it != includeTags.end(); ++it)
+      {
+        if (first)
+        {
+          first = false;
+        }
+        else
+        {
+          s += ",";
+        }
+
+        char buf[16];
+        sprintf(buf, "%04X%04X", it->GetGroup(), it->GetElement());
+        s += std::string(buf);
+      }
+
+      arguments["includefield"] = s;
+    }    
+  }
+  
+  
+  void DicomResourcesLoader::ScheduleGetDicomWeb(boost::shared_ptr<LoadedDicomResources> target,
+                                                 int priority,
+                                                 const DicomSource& source,
+                                                 const std::string& uri,
+                                                 const std::set<Orthanc::DicomTag>& includeTags,
+                                                 Orthanc::IDynamicObject* userPayload)
+  {
+    boost::shared_ptr<Orthanc::IDynamicObject> protection(userPayload);
+    
+    if (!source.IsDicomWeb())
+    {
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls, "Not a DICOMweb source");
+    }
+
+    std::map<std::string, std::string> arguments, headers;
+    SetIncludeTags(arguments, includeTags);
+  
+    std::unique_ptr<IOracleCommand> command(
+      source.CreateDicomWebCommand(uri, arguments, headers, 
+                                   new DicomWebHandler(shared_from_this(), target, priority, source, protection)));
+      
+    {
+      std::unique_ptr<ILoadersContext::ILock> lock(context_.Lock());
+      lock->Schedule(GetSharedObserver(), priority, command.release());
+    }
+  }
+  
+
+  void DicomResourcesLoader::ScheduleQido(boost::shared_ptr<LoadedDicomResources> target,
+                                          int priority,
+                                          const DicomSource& source,
+                                          Orthanc::ResourceType level,
+                                          const Orthanc::DicomMap& filter,
+                                          const std::set<Orthanc::DicomTag>& includeTags,
+                                          Orthanc::IDynamicObject* userPayload)
+  {
+    boost::shared_ptr<Orthanc::IDynamicObject> protection(userPayload);
+    
+    if (!source.IsDicomWeb())
+    {
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls, "Not a DICOMweb source");
+    }
+
+    std::string uri;
+    switch (level)
+    {
+      case Orthanc::ResourceType_Study:
+        uri = "/studies";
+        break;
+
+      case Orthanc::ResourceType_Series:
+        uri = "/series";
+        break;
+
+      case Orthanc::ResourceType_Instance:
+        uri = "/instances";
+        break;
+
+      default:
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_ParameterOutOfRange);
+    }
+
+    std::set<Orthanc::DicomTag> tags;
+    filter.GetTags(tags);
+
+    std::map<std::string, std::string> arguments, headers;
+
+    for (std::set<Orthanc::DicomTag>::const_iterator it = tags.begin(); it != tags.end(); ++it)
+    {
+      std::string s;
+      if (filter.LookupStringValue(s, *it, false /* no binary */))
+      {
+        char buf[16];
+        sprintf(buf, "%04X%04X", it->GetGroup(), it->GetElement());
+        arguments[buf] = s;
+      }
+    }
+
+    SetIncludeTags(arguments, includeTags);
+
+    std::unique_ptr<IOracleCommand> command(
+      source.CreateDicomWebCommand(uri, arguments, headers, 
+                                   new DicomWebHandler(shared_from_this(), target, priority, source, protection)));
+
+
+    {
+      std::unique_ptr<ILoadersContext::ILock> lock(context_.Lock());
+      lock->Schedule(GetSharedObserver(), priority, command.release());
+    }
+  }
+
+    
+  void DicomResourcesLoader::ScheduleLoadOrthancResources(boost::shared_ptr<LoadedDicomResources> target,
+                                                          int priority,
+                                                          const DicomSource& source,
+                                                          Orthanc::ResourceType topLevel,
+                                                          const std::string& topId,
+                                                          Orthanc::ResourceType bottomLevel,
+                                                          Orthanc::IDynamicObject* userPayload)
+  {
+    boost::shared_ptr<Orthanc::IDynamicObject> protection(userPayload);
+    
+    if (!source.IsOrthanc())
+    {
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls, "Not an Orthanc source");
+    }
+
+    bool ok = false;
+
+    switch (topLevel)
+    {
+      case Orthanc::ResourceType_Patient:
+        ok = (bottomLevel == Orthanc::ResourceType_Patient ||
+              bottomLevel == Orthanc::ResourceType_Study ||
+              bottomLevel == Orthanc::ResourceType_Series ||
+              bottomLevel == Orthanc::ResourceType_Instance);
+        break;
+              
+      case Orthanc::ResourceType_Study:
+        ok = (bottomLevel == Orthanc::ResourceType_Study ||
+              bottomLevel == Orthanc::ResourceType_Series ||
+              bottomLevel == Orthanc::ResourceType_Instance);
+        break;
+              
+      case Orthanc::ResourceType_Series:
+        ok = (bottomLevel == Orthanc::ResourceType_Series ||
+              bottomLevel == Orthanc::ResourceType_Instance);
+        break;
+              
+      case Orthanc::ResourceType_Instance:
+        ok = (bottomLevel == Orthanc::ResourceType_Instance);
+        break;
+
+      default:
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_ParameterOutOfRange);
+    }
+
+    if (!ok)
+    {
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_ParameterOutOfRange);
+    }
+
+    boost::shared_ptr<unsigned int> remainingCommands(new unsigned int(0));
+
+    if (topLevel == Orthanc::ResourceType_Instance)
+    {
+      ScheduleLoadOrthancInstanceTags(target, priority, source, topId, remainingCommands, protection);
+    }
+    else if (topLevel == bottomLevel)
+    {
+      ScheduleLoadOrthancOneChildInstance(target, priority, source, topLevel, topId, remainingCommands, protection);
+    }
+    else 
+    {
+      std::unique_ptr<OrthancRestApiCommand> command(new OrthancRestApiCommand);
+      command->SetUri("/" + GetUri(topLevel) + "/" + topId + "/" + GetUri(bottomLevel));
+      command->AcquirePayload(new OrthancAllChildrenInstancesHandler
+                              (shared_from_this(), target, priority, source,
+                               remainingCommands, bottomLevel, protection));
+
+      {
+        std::unique_ptr<ILoadersContext::ILock> lock(context_.Lock());
+
+        // GetSharedObserver() means "this" (for use as an IObserver), as a 
+        // shared_ptr
+        // The oracle will thus call "this" 
+        lock->Schedule(GetSharedObserver(), priority, command.release());
+      }
+    }
+  }
+
+
+  void DicomResourcesLoader::ScheduleLoadDicomDir(boost::shared_ptr<LoadedDicomResources> target,
+                                                  int priority,
+                                                  const DicomSource& source,
+                                                  const std::string& path,
+                                                  Orthanc::IDynamicObject* userPayload)
+  {
+    boost::shared_ptr<Orthanc::IDynamicObject> protection(userPayload);
+    
+    if (!source.IsDicomDir())
+    {
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls, "Not a DICOMDIR source");
+    }
+
+    if (target->GetIndexedTag() == Orthanc::DICOM_TAG_SOP_INSTANCE_UID)
+    {
+      LOG(WARNING) << "If loading DICOMDIR, it is advised to index tag "
+                   << "ReferencedSopInstanceUidInFile (0004,1511)";
+    }
+
+#if ORTHANC_ENABLE_DCMTK == 1
+    std::unique_ptr<ReadFileCommand> command(new ReadFileCommand(path));
+    command->AcquirePayload(new DicomDirHandler(shared_from_this(), target, priority, source, protection));
+
+    {
+      std::unique_ptr<ILoadersContext::ILock> lock(context_.Lock());      
+      lock->Schedule(GetSharedObserver(), priority, command.release());
+    }
+#else
+    throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError,
+                                    "DCMTK is disabled, cannot load DICOMDIR");
+#endif
+  }
+
+
+  void DicomResourcesLoader::ScheduleLoadDicomFile(boost::shared_ptr<LoadedDicomResources> target,
+                                                   int priority,
+                                                   const DicomSource& source,
+                                                   const std::string& path,
+                                                   bool includePixelData,
+                                                   Orthanc::IDynamicObject* userPayload)
+  {
+    boost::shared_ptr<Orthanc::IDynamicObject> protection(userPayload);
+    
+#if ORTHANC_ENABLE_DCMTK == 1
+    std::unique_ptr<ParseDicomFromFileCommand> command(new ParseDicomFromFileCommand(source, path));
+    command->SetPixelDataIncluded(includePixelData);
+    command->AcquirePayload(new Handler(shared_from_this(), target, priority, source, protection));
+
+    {
+      std::unique_ptr<ILoadersContext::ILock> lock(context_.Lock());
+      lock->Schedule(GetSharedObserver(), priority, command.release());
+    }
+#else
+    throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError,
+                                    "DCMTK is disabled, cannot load DICOM files");
+#endif
+  }
+
+
+  bool DicomResourcesLoader::ScheduleLoadDicomFile(boost::shared_ptr<LoadedDicomResources> target,
+                                                   int priority,
+                                                   const DicomSource& source,
+                                                   const std::string& dicomDirPath,
+                                                   const Orthanc::DicomMap& dicomDirEntry,
+                                                   bool includePixelData,
+                                                   Orthanc::IDynamicObject* userPayload)
+  {
+    std::unique_ptr<Orthanc::IDynamicObject> protection(userPayload);
+    
+#if ORTHANC_ENABLE_DCMTK == 1
+    std::string file;
+    if (dicomDirEntry.LookupStringValue(file, Orthanc::DICOM_TAG_REFERENCED_FILE_ID, false))
+    {
+      ScheduleLoadDicomFile(target, priority, source, ParseDicomFromFileCommand::GetDicomDirPath(dicomDirPath, file),
+                            includePixelData, protection.release());
+      return true;
+    }
+    else
+    {
+      return false;
+    }
+#else
+    throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError,
+                                    "DCMTK is disabled, cannot load DICOM files");
+#endif
+  }
+}