--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancServer/Plugins/Engine/OrthancPluginDatabase.cpp	Wed Jun 10 20:30:34 2020 +0200
@@ -0,0 +1,1534 @@
+/**
+ * Orthanc - A Lightweight, RESTful DICOM Store
+ * 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 General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * In addition, as a special exception, the copyright holders of this
+ * program give permission to link the code of its release with the
+ * OpenSSL project's "OpenSSL" library (or with modified versions of it
+ * that use the same license as the "OpenSSL" library), and distribute
+ * the linked executables. You must obey the GNU General Public License
+ * in all respects for all of the code used other than "OpenSSL". If you
+ * modify file(s) with this exception, you may extend this exception to
+ * your version of the file(s), but you are not obligated to do so. If
+ * you do not wish to do so, delete this exception statement from your
+ * version. If you delete this exception statement from all source files
+ * in the program, then also delete it here.
+ * 
+ * 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, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+#include "../../OrthancServer/PrecompiledHeadersServer.h"
+#include "OrthancPluginDatabase.h"
+
+#if ORTHANC_ENABLE_PLUGINS != 1
+#error The plugin support is disabled
+#endif
+
+
+#include "../../Core/Logging.h"
+#include "../../Core/OrthancException.h"
+#include "PluginsEnumerations.h"
+
+#include <cassert>
+
+namespace Orthanc
+{
+  class OrthancPluginDatabase::Transaction : public IDatabaseWrapper::ITransaction
+  {
+  private:
+    OrthancPluginDatabase&  that_;
+
+    void CheckSuccess(OrthancPluginErrorCode code) const
+    {
+      if (code != OrthancPluginErrorCode_Success)
+      {
+        that_.errorDictionary_.LogError(code, true);
+        throw OrthancException(static_cast<ErrorCode>(code));
+      }
+    }
+
+  public:
+    Transaction(OrthancPluginDatabase& that) :
+    that_(that)
+    {
+    }
+
+    virtual void Begin()
+    {
+      CheckSuccess(that_.backend_.startTransaction(that_.payload_));
+    }
+
+    virtual void Rollback()
+    {
+      CheckSuccess(that_.backend_.rollbackTransaction(that_.payload_));
+    }
+
+    virtual void Commit(int64_t diskSizeDelta)
+    {
+      if (that_.fastGetTotalSize_)
+      {
+        CheckSuccess(that_.backend_.commitTransaction(that_.payload_));
+      }
+      else
+      {
+        if (static_cast<int64_t>(that_.currentDiskSize_) + diskSizeDelta < 0)
+        {
+          throw OrthancException(ErrorCode_DatabasePlugin);
+        }
+
+        uint64_t newDiskSize = (that_.currentDiskSize_ + diskSizeDelta);
+
+        assert(newDiskSize == that_.GetTotalCompressedSize());
+
+        CheckSuccess(that_.backend_.commitTransaction(that_.payload_));
+
+        // The transaction has succeeded, we can commit the new disk size
+        that_.currentDiskSize_ = newDiskSize;
+      }
+    }
+  };
+
+
+  static FileInfo Convert(const OrthancPluginAttachment& attachment)
+  {
+    return FileInfo(attachment.uuid,
+                    static_cast<FileContentType>(attachment.contentType),
+                    attachment.uncompressedSize,
+                    attachment.uncompressedHash,
+                    static_cast<CompressionType>(attachment.compressionType),
+                    attachment.compressedSize,
+                    attachment.compressedHash);
+  }
+
+
+  void OrthancPluginDatabase::CheckSuccess(OrthancPluginErrorCode code)
+  {
+    if (code != OrthancPluginErrorCode_Success)
+    {
+      errorDictionary_.LogError(code, true);
+      throw OrthancException(static_cast<ErrorCode>(code));
+    }
+  }
+
+
+  void OrthancPluginDatabase::ResetAnswers()
+  {
+    type_ = _OrthancPluginDatabaseAnswerType_None;
+
+    answerDicomMap_ = NULL;
+    answerChanges_ = NULL;
+    answerExportedResources_ = NULL;
+    answerDone_ = NULL;
+    answerMatchingResources_ = NULL;
+    answerMatchingInstances_ = NULL;
+    answerMetadata_ = NULL;
+  }
+
+
+  void OrthancPluginDatabase::ForwardAnswers(std::list<int64_t>& target)
+  {
+    if (type_ != _OrthancPluginDatabaseAnswerType_None &&
+        type_ != _OrthancPluginDatabaseAnswerType_Int64)
+    {
+      throw OrthancException(ErrorCode_DatabasePlugin);
+    }
+
+    target.clear();
+
+    if (type_ == _OrthancPluginDatabaseAnswerType_Int64)
+    {
+      for (std::list<int64_t>::const_iterator 
+             it = answerInt64_.begin(); it != answerInt64_.end(); ++it)
+      {
+        target.push_back(*it);
+      }
+    }
+  }
+
+
+  void OrthancPluginDatabase::ForwardAnswers(std::list<std::string>& target)
+  {
+    if (type_ != _OrthancPluginDatabaseAnswerType_None &&
+        type_ != _OrthancPluginDatabaseAnswerType_String)
+    {
+      throw OrthancException(ErrorCode_DatabasePlugin);
+    }
+
+    target.clear();
+
+    if (type_ == _OrthancPluginDatabaseAnswerType_String)
+    {
+      for (std::list<std::string>::const_iterator 
+             it = answerStrings_.begin(); it != answerStrings_.end(); ++it)
+      {
+        target.push_back(*it);
+      }
+    }
+  }
+
+
+  bool OrthancPluginDatabase::ForwardSingleAnswer(std::string& target)
+  {
+    if (type_ == _OrthancPluginDatabaseAnswerType_None)
+    {
+      return false;
+    }
+    else if (type_ == _OrthancPluginDatabaseAnswerType_String &&
+             answerStrings_.size() == 1)
+    {
+      target = answerStrings_.front();
+      return true; 
+    }
+    else
+    {
+      throw OrthancException(ErrorCode_DatabasePlugin);
+    }
+  }
+
+
+  bool OrthancPluginDatabase::ForwardSingleAnswer(int64_t& target)
+  {
+    if (type_ == _OrthancPluginDatabaseAnswerType_None)
+    {
+      return false;
+    }
+    else if (type_ == _OrthancPluginDatabaseAnswerType_Int64 &&
+             answerInt64_.size() == 1)
+    {
+      target = answerInt64_.front();
+      return true; 
+    }
+    else
+    {
+      throw OrthancException(ErrorCode_DatabasePlugin);
+    }
+  }
+
+
+  OrthancPluginDatabase::OrthancPluginDatabase(SharedLibrary& library,
+                                               PluginsErrorDictionary&  errorDictionary,
+                                               const OrthancPluginDatabaseBackend& backend,
+                                               const OrthancPluginDatabaseExtensions* extensions,
+                                               size_t extensionsSize,
+                                               void *payload) : 
+    library_(library),
+    errorDictionary_(errorDictionary),
+    backend_(backend),
+    payload_(payload),
+    listener_(NULL)
+  {
+    static const char* const MISSING = "  Missing extension in database index plugin: ";
+    
+    ResetAnswers();
+
+    memset(&extensions_, 0, sizeof(extensions_));
+
+    size_t size = sizeof(extensions_);
+    if (extensionsSize < size)
+    {
+      size = extensionsSize;  // Not all the extensions are available
+    }
+
+    memcpy(&extensions_, extensions, size);
+
+    bool isOptimal = true;
+
+    if (extensions_.lookupResources == NULL)
+    {
+      LOG(INFO) << MISSING << "LookupIdentifierRange()";
+      isOptimal = false;
+    }
+
+    if (extensions_.createInstance == NULL)
+    {
+      LOG(INFO) << MISSING << "CreateInstance()";
+      isOptimal = false;
+    }
+
+    if (extensions_.setResourcesContent == NULL)
+    {
+      LOG(INFO) << MISSING << "SetResourcesContent()";
+      isOptimal = false;
+    }
+
+    if (extensions_.getChildrenMetadata == NULL)
+    {
+      LOG(INFO) << MISSING << "GetChildrenMetadata()";
+      isOptimal = false;
+    }
+
+    if (extensions_.getAllMetadata == NULL)
+    {
+      LOG(INFO) << MISSING << "GetAllMetadata()";
+      isOptimal = false;
+    }
+
+    if (extensions_.lookupResourceAndParent == NULL)
+    {
+      LOG(INFO) << MISSING << "LookupResourceAndParent()";
+      isOptimal = false;
+    }
+
+    if (isOptimal)
+    {
+      LOG(INFO) << "The performance of the database index plugin "
+                << "is optimal for this version of Orthanc";
+    }
+    else
+    {
+      LOG(WARNING) << "Performance warning in the database index: "
+                   << "Some extensions are missing in the plugin";
+    }
+
+    if (extensions_.getLastChangeIndex == NULL)
+    {
+      LOG(WARNING) << "The database extension GetLastChangeIndex() is missing";
+    }
+
+    if (extensions_.tagMostRecentPatient == NULL)
+    {
+      LOG(WARNING) << "The database extension TagMostRecentPatient() is missing "
+                   << "(affected by issue 58)";
+    }
+  }
+
+
+  void OrthancPluginDatabase::Open()
+  {
+    CheckSuccess(backend_.open(payload_));
+
+    {
+      Transaction transaction(*this);
+      transaction.Begin();
+
+      std::string tmp;
+      fastGetTotalSize_ =
+        (LookupGlobalProperty(tmp, GlobalProperty_GetTotalSizeIsFast) &&
+         tmp == "1");
+      
+      if (fastGetTotalSize_)
+      {
+        currentDiskSize_ = 0;   // Unused
+      }
+      else
+      {
+        // This is the case of database plugins using Orthanc SDK <= 1.5.2
+        LOG(WARNING) << "Your database index plugin is not compatible with multiple Orthanc writers";
+        currentDiskSize_ = GetTotalCompressedSize();
+      }
+
+      transaction.Commit(0);
+    }
+  }
+
+
+  void OrthancPluginDatabase::AddAttachment(int64_t id,
+                                            const FileInfo& attachment)
+  {
+    OrthancPluginAttachment tmp;
+    tmp.uuid = attachment.GetUuid().c_str();
+    tmp.contentType = static_cast<int32_t>(attachment.GetContentType());
+    tmp.uncompressedSize = attachment.GetUncompressedSize();
+    tmp.uncompressedHash = attachment.GetUncompressedMD5().c_str();
+    tmp.compressionType = static_cast<int32_t>(attachment.GetCompressionType());
+    tmp.compressedSize = attachment.GetCompressedSize();
+    tmp.compressedHash = attachment.GetCompressedMD5().c_str();
+
+    CheckSuccess(backend_.addAttachment(payload_, id, &tmp));
+  }
+
+
+  void OrthancPluginDatabase::AttachChild(int64_t parent,
+                                          int64_t child)
+  {
+    CheckSuccess(backend_.attachChild(payload_, parent, child));
+  }
+
+
+  void OrthancPluginDatabase::ClearChanges()
+  {
+    CheckSuccess(backend_.clearChanges(payload_));
+  }
+
+
+  void OrthancPluginDatabase::ClearExportedResources()
+  {
+    CheckSuccess(backend_.clearExportedResources(payload_));
+  }
+
+
+  int64_t OrthancPluginDatabase::CreateResource(const std::string& publicId,
+                                                ResourceType type)
+  {
+    int64_t id;
+    CheckSuccess(backend_.createResource(&id, payload_, publicId.c_str(), Plugins::Convert(type)));
+    return id;
+  }
+
+
+  void OrthancPluginDatabase::DeleteAttachment(int64_t id,
+                                               FileContentType attachment)
+  {
+    CheckSuccess(backend_.deleteAttachment(payload_, id, static_cast<int32_t>(attachment)));
+  }
+
+
+  void OrthancPluginDatabase::DeleteMetadata(int64_t id,
+                                             MetadataType type)
+  {
+    CheckSuccess(backend_.deleteMetadata(payload_, id, static_cast<int32_t>(type)));
+  }
+
+
+  void OrthancPluginDatabase::DeleteResource(int64_t id)
+  {
+    CheckSuccess(backend_.deleteResource(payload_, id));
+  }
+
+
+  void OrthancPluginDatabase::GetAllMetadata(std::map<MetadataType, std::string>& target,
+                                             int64_t id)
+  {
+    if (extensions_.getAllMetadata == NULL)
+    {
+      // Fallback implementation if extension is missing
+      target.clear();
+
+      ResetAnswers();
+      CheckSuccess(backend_.listAvailableMetadata(GetContext(), payload_, id));
+
+      if (type_ != _OrthancPluginDatabaseAnswerType_None &&
+          type_ != _OrthancPluginDatabaseAnswerType_Int32)
+      {
+        throw OrthancException(ErrorCode_DatabasePlugin);
+      }
+
+      target.clear();
+
+      if (type_ == _OrthancPluginDatabaseAnswerType_Int32)
+      {
+        for (std::list<int32_t>::const_iterator 
+               it = answerInt32_.begin(); it != answerInt32_.end(); ++it)
+        {
+          MetadataType type = static_cast<MetadataType>(*it);
+
+          std::string value;
+          if (LookupMetadata(value, id, type))
+          {
+            target[type] = value;
+          }
+        }
+      }
+    }
+    else
+    {
+      ResetAnswers();
+
+      answerMetadata_ = &target;
+      target.clear();
+      
+      CheckSuccess(extensions_.getAllMetadata(GetContext(), payload_, id));
+
+      if (type_ != _OrthancPluginDatabaseAnswerType_None &&
+          type_ != _OrthancPluginDatabaseAnswerType_Metadata)
+      {
+        throw OrthancException(ErrorCode_DatabasePlugin);
+      }
+    }
+  }
+
+
+  void OrthancPluginDatabase::GetAllInternalIds(std::list<int64_t>& target,
+                                                ResourceType resourceType)
+  {
+    if (extensions_.getAllInternalIds == NULL)
+    {
+      throw OrthancException(ErrorCode_DatabasePlugin,
+                             "The database plugin does not implement the mandatory GetAllInternalIds() extension");
+    }
+
+    ResetAnswers();
+    CheckSuccess(extensions_.getAllInternalIds(GetContext(), payload_, Plugins::Convert(resourceType)));
+    ForwardAnswers(target);
+  }
+
+
+  void OrthancPluginDatabase::GetAllPublicIds(std::list<std::string>& target,
+                                              ResourceType resourceType)
+  {
+    ResetAnswers();
+    CheckSuccess(backend_.getAllPublicIds(GetContext(), payload_, Plugins::Convert(resourceType)));
+    ForwardAnswers(target);
+  }
+
+
+  void OrthancPluginDatabase::GetAllPublicIds(std::list<std::string>& target,
+                                              ResourceType resourceType,
+                                              size_t since,
+                                              size_t limit)
+  {
+    if (extensions_.getAllPublicIdsWithLimit != NULL)
+    {
+      // This extension is available since Orthanc 0.9.4
+      ResetAnswers();
+      CheckSuccess(extensions_.getAllPublicIdsWithLimit
+                   (GetContext(), payload_, Plugins::Convert(resourceType), since, limit));
+      ForwardAnswers(target);
+    }
+    else
+    {
+      // The extension is not available in the database plugin, use a
+      // fallback implementation
+      target.clear();
+
+      if (limit == 0)
+      {
+        return;
+      }
+
+      std::list<std::string> tmp;
+      GetAllPublicIds(tmp, resourceType);
+    
+      if (tmp.size() <= since)
+      {
+        // Not enough results => empty answer
+        return;
+      }
+
+      std::list<std::string>::iterator current = tmp.begin();
+      std::advance(current, since);
+
+      while (limit > 0 && current != tmp.end())
+      {
+        target.push_back(*current);
+        --limit;
+        ++current;
+      }
+    }
+  }
+
+
+
+  void OrthancPluginDatabase::GetChanges(std::list<ServerIndexChange>& target /*out*/,
+                                         bool& done /*out*/,
+                                         int64_t since,
+                                         uint32_t maxResults)
+  {
+    ResetAnswers();
+    answerChanges_ = &target;
+    answerDone_ = &done;
+    done = false;
+
+    CheckSuccess(backend_.getChanges(GetContext(), payload_, since, maxResults));
+  }
+
+
+  void OrthancPluginDatabase::GetChildrenInternalId(std::list<int64_t>& target,
+                                                    int64_t id)
+  {
+    ResetAnswers();
+    CheckSuccess(backend_.getChildrenInternalId(GetContext(), payload_, id));
+    ForwardAnswers(target);
+  }
+
+
+  void OrthancPluginDatabase::GetChildrenPublicId(std::list<std::string>& target,
+                                                  int64_t id)
+  {
+    ResetAnswers();
+    CheckSuccess(backend_.getChildrenPublicId(GetContext(), payload_, id));
+    ForwardAnswers(target);
+  }
+
+
+  void OrthancPluginDatabase::GetExportedResources(std::list<ExportedResource>& target /*out*/,
+                                                   bool& done /*out*/,
+                                                   int64_t since,
+                                                   uint32_t maxResults)
+  {
+    ResetAnswers();
+    answerExportedResources_ = &target;
+    answerDone_ = &done;
+    done = false;
+
+    CheckSuccess(backend_.getExportedResources(GetContext(), payload_, since, maxResults));
+  }
+
+
+  void OrthancPluginDatabase::GetLastChange(std::list<ServerIndexChange>& target /*out*/)
+  {
+    bool ignored = false;
+
+    ResetAnswers();
+    answerChanges_ = &target;
+    answerDone_ = &ignored;
+
+    CheckSuccess(backend_.getLastChange(GetContext(), payload_));
+  }
+
+
+  void OrthancPluginDatabase::GetLastExportedResource(std::list<ExportedResource>& target /*out*/)
+  {
+    bool ignored = false;
+
+    ResetAnswers();
+    answerExportedResources_ = &target;
+    answerDone_ = &ignored;
+
+    CheckSuccess(backend_.getLastExportedResource(GetContext(), payload_));
+  }
+
+
+  void OrthancPluginDatabase::GetMainDicomTags(DicomMap& map,
+                                               int64_t id)
+  {
+    ResetAnswers();
+    answerDicomMap_ = &map;
+
+    CheckSuccess(backend_.getMainDicomTags(GetContext(), payload_, id));
+  }
+
+
+  std::string OrthancPluginDatabase::GetPublicId(int64_t resourceId)
+  {
+    ResetAnswers();
+    std::string s;
+
+    CheckSuccess(backend_.getPublicId(GetContext(), payload_, resourceId));
+
+    if (!ForwardSingleAnswer(s))
+    {
+      throw OrthancException(ErrorCode_DatabasePlugin);
+    }
+
+    return s;
+  }
+
+
+  uint64_t OrthancPluginDatabase::GetResourceCount(ResourceType resourceType)
+  {
+    uint64_t count;
+    CheckSuccess(backend_.getResourceCount(&count, payload_, Plugins::Convert(resourceType)));
+    return count;
+  }
+
+
+  ResourceType OrthancPluginDatabase::GetResourceType(int64_t resourceId)
+  {
+    OrthancPluginResourceType type;
+    CheckSuccess(backend_.getResourceType(&type, payload_, resourceId));
+    return Plugins::Convert(type);
+  }
+
+
+  uint64_t OrthancPluginDatabase::GetTotalCompressedSize()
+  {
+    uint64_t size;
+    CheckSuccess(backend_.getTotalCompressedSize(&size, payload_));
+    return size;
+  }
+
+    
+  uint64_t OrthancPluginDatabase::GetTotalUncompressedSize()
+  {
+    uint64_t size;
+    CheckSuccess(backend_.getTotalUncompressedSize(&size, payload_));
+    return size;
+  }
+
+
+  bool OrthancPluginDatabase::IsExistingResource(int64_t internalId)
+  {
+    int32_t existing;
+    CheckSuccess(backend_.isExistingResource(&existing, payload_, internalId));
+    return (existing != 0);
+  }
+
+
+  bool OrthancPluginDatabase::IsProtectedPatient(int64_t internalId)
+  {
+    int32_t isProtected;
+    CheckSuccess(backend_.isProtectedPatient(&isProtected, payload_, internalId));
+    return (isProtected != 0);
+  }
+
+
+  void OrthancPluginDatabase::ListAvailableAttachments(std::list<FileContentType>& target,
+                                                       int64_t id)
+  {
+    ResetAnswers();
+
+    CheckSuccess(backend_.listAvailableAttachments(GetContext(), payload_, id));
+
+    if (type_ != _OrthancPluginDatabaseAnswerType_None &&
+        type_ != _OrthancPluginDatabaseAnswerType_Int32)
+    {
+      throw OrthancException(ErrorCode_DatabasePlugin);
+    }
+
+    target.clear();
+
+    if (type_ == _OrthancPluginDatabaseAnswerType_Int32)
+    {
+      for (std::list<int32_t>::const_iterator 
+             it = answerInt32_.begin(); it != answerInt32_.end(); ++it)
+      {
+        target.push_back(static_cast<FileContentType>(*it));
+      }
+    }
+  }
+
+
+  void OrthancPluginDatabase::LogChange(int64_t internalId,
+                                        const ServerIndexChange& change)
+  {
+    OrthancPluginChange tmp;
+    tmp.seq = change.GetSeq();
+    tmp.changeType = static_cast<int32_t>(change.GetChangeType());
+    tmp.resourceType = Plugins::Convert(change.GetResourceType());
+    tmp.publicId = change.GetPublicId().c_str();
+    tmp.date = change.GetDate().c_str();
+
+    CheckSuccess(backend_.logChange(payload_, &tmp));
+  }
+
+
+  void OrthancPluginDatabase::LogExportedResource(const ExportedResource& resource)
+  {
+    OrthancPluginExportedResource tmp;
+    tmp.seq = resource.GetSeq();
+    tmp.resourceType = Plugins::Convert(resource.GetResourceType());
+    tmp.publicId = resource.GetPublicId().c_str();
+    tmp.modality = resource.GetModality().c_str();
+    tmp.date = resource.GetDate().c_str();
+    tmp.patientId = resource.GetPatientId().c_str();
+    tmp.studyInstanceUid = resource.GetStudyInstanceUid().c_str();
+    tmp.seriesInstanceUid = resource.GetSeriesInstanceUid().c_str();
+    tmp.sopInstanceUid = resource.GetSopInstanceUid().c_str();
+
+    CheckSuccess(backend_.logExportedResource(payload_, &tmp));
+  }
+
+    
+  bool OrthancPluginDatabase::LookupAttachment(FileInfo& attachment,
+                                               int64_t id,
+                                               FileContentType contentType)
+  {
+    ResetAnswers();
+
+    CheckSuccess(backend_.lookupAttachment
+                 (GetContext(), payload_, id, static_cast<int32_t>(contentType)));
+
+    if (type_ == _OrthancPluginDatabaseAnswerType_None)
+    {
+      return false;
+    }
+    else if (type_ == _OrthancPluginDatabaseAnswerType_Attachment &&
+             answerAttachments_.size() == 1)
+    {
+      attachment = answerAttachments_.front();
+      return true; 
+    }
+    else
+    {
+      throw OrthancException(ErrorCode_DatabasePlugin);
+    }
+  }
+
+
+  bool OrthancPluginDatabase::LookupGlobalProperty(std::string& target,
+                                                   GlobalProperty property)
+  {
+    ResetAnswers();
+
+    CheckSuccess(backend_.lookupGlobalProperty
+                 (GetContext(), payload_, static_cast<int32_t>(property)));
+
+    return ForwardSingleAnswer(target);
+  }
+
+
+  bool OrthancPluginDatabase::LookupMetadata(std::string& target,
+                                             int64_t id,
+                                             MetadataType type)
+  {
+    ResetAnswers();
+    CheckSuccess(backend_.lookupMetadata(GetContext(), payload_, id, static_cast<int32_t>(type)));
+    return ForwardSingleAnswer(target);
+  }
+
+
+  bool OrthancPluginDatabase::LookupParent(int64_t& parentId,
+                                           int64_t resourceId)
+  {
+    ResetAnswers();
+    CheckSuccess(backend_.lookupParent(GetContext(), payload_, resourceId));
+    return ForwardSingleAnswer(parentId);
+  }
+
+
+  bool OrthancPluginDatabase::LookupResource(int64_t& id,
+                                             ResourceType& type,
+                                             const std::string& publicId)
+  {
+    ResetAnswers();
+
+    CheckSuccess(backend_.lookupResource(GetContext(), payload_, publicId.c_str()));
+
+    if (type_ == _OrthancPluginDatabaseAnswerType_None)
+    {
+      return false;
+    }
+    else if (type_ == _OrthancPluginDatabaseAnswerType_Resource &&
+             answerResources_.size() == 1)
+    {
+      id = answerResources_.front().first;
+      type = answerResources_.front().second;
+      return true; 
+    }
+    else
+    {
+      throw OrthancException(ErrorCode_DatabasePlugin);
+    }
+  }
+
+
+  bool OrthancPluginDatabase::SelectPatientToRecycle(int64_t& internalId)
+  {
+    ResetAnswers();
+    CheckSuccess(backend_.selectPatientToRecycle(GetContext(), payload_));
+    return ForwardSingleAnswer(internalId);
+  }
+
+
+  bool OrthancPluginDatabase::SelectPatientToRecycle(int64_t& internalId,
+                                                     int64_t patientIdToAvoid)
+  {
+    ResetAnswers();
+    CheckSuccess(backend_.selectPatientToRecycle2(GetContext(), payload_, patientIdToAvoid));
+    return ForwardSingleAnswer(internalId);
+  }
+
+
+  void OrthancPluginDatabase::SetGlobalProperty(GlobalProperty property,
+                                                const std::string& value)
+  {
+    CheckSuccess(backend_.setGlobalProperty
+                 (payload_, static_cast<int32_t>(property), value.c_str()));
+  }
+
+
+  void OrthancPluginDatabase::ClearMainDicomTags(int64_t id)
+  {
+    if (extensions_.clearMainDicomTags == NULL)
+    {
+      throw OrthancException(ErrorCode_DatabasePlugin,
+                             "Your custom index plugin does not implement the mandatory ClearMainDicomTags() extension");
+    }
+
+    CheckSuccess(extensions_.clearMainDicomTags(payload_, id));
+  }
+
+
+  void OrthancPluginDatabase::SetMainDicomTag(int64_t id,
+                                              const DicomTag& tag,
+                                              const std::string& value)
+  {
+    OrthancPluginDicomTag tmp;
+    tmp.group = tag.GetGroup();
+    tmp.element = tag.GetElement();
+    tmp.value = value.c_str();
+
+    CheckSuccess(backend_.setMainDicomTag(payload_, id, &tmp));
+  }
+
+
+  void OrthancPluginDatabase::SetIdentifierTag(int64_t id,
+                                               const DicomTag& tag,
+                                               const std::string& value)
+  {
+    OrthancPluginDicomTag tmp;
+    tmp.group = tag.GetGroup();
+    tmp.element = tag.GetElement();
+    tmp.value = value.c_str();
+
+    CheckSuccess(backend_.setIdentifierTag(payload_, id, &tmp));
+  }
+
+
+  void OrthancPluginDatabase::SetMetadata(int64_t id,
+                                          MetadataType type,
+                                          const std::string& value)
+  {
+    CheckSuccess(backend_.setMetadata
+                 (payload_, id, static_cast<int32_t>(type), value.c_str()));
+  }
+
+
+  void OrthancPluginDatabase::SetProtectedPatient(int64_t internalId, 
+                                                  bool isProtected)
+  {
+    CheckSuccess(backend_.setProtectedPatient(payload_, internalId, isProtected));
+  }
+
+
+  IDatabaseWrapper::ITransaction* OrthancPluginDatabase::StartTransaction()
+  {
+    return new Transaction(*this);
+  }
+
+
+  static void ProcessEvent(IDatabaseListener& listener,
+                           const _OrthancPluginDatabaseAnswer& answer)
+  {
+    switch (answer.type)
+    {
+      case _OrthancPluginDatabaseAnswerType_DeletedAttachment:
+      {
+        const OrthancPluginAttachment& attachment = 
+          *reinterpret_cast<const OrthancPluginAttachment*>(answer.valueGeneric);
+        listener.SignalFileDeleted(Convert(attachment));
+        break;
+      }
+        
+      case _OrthancPluginDatabaseAnswerType_RemainingAncestor:
+      {
+        ResourceType type = Plugins::Convert(static_cast<OrthancPluginResourceType>(answer.valueInt32));
+        listener.SignalRemainingAncestor(type, answer.valueString);
+        break;
+      }
+      
+      case _OrthancPluginDatabaseAnswerType_DeletedResource:
+      {
+        ResourceType type = Plugins::Convert(static_cast<OrthancPluginResourceType>(answer.valueInt32));
+        ServerIndexChange change(ChangeType_Deleted, type, answer.valueString);
+        listener.SignalChange(change);
+        break;
+      }
+
+      default:
+        throw OrthancException(ErrorCode_DatabasePlugin);
+    }
+  }
+
+
+  unsigned int OrthancPluginDatabase::GetDatabaseVersion()
+  {
+    if (extensions_.getDatabaseVersion != NULL)
+    {
+      uint32_t version;
+      CheckSuccess(extensions_.getDatabaseVersion(&version, payload_));
+      return version;
+    }
+    else
+    {
+      // Before adding the "GetDatabaseVersion()" extension in plugins
+      // (OrthancPostgreSQL <= 1.2), the only supported DB schema was
+      // version 5.
+      return 5;
+    }
+  }
+
+
+  void OrthancPluginDatabase::Upgrade(unsigned int targetVersion,
+                                      IStorageArea& storageArea)
+  {
+    if (extensions_.upgradeDatabase != NULL)
+    {
+      Transaction transaction(*this);
+      transaction.Begin();
+
+      OrthancPluginErrorCode code = extensions_.upgradeDatabase(
+        payload_, targetVersion, 
+        reinterpret_cast<OrthancPluginStorageArea*>(&storageArea));
+
+      if (code == OrthancPluginErrorCode_Success)
+      {
+        transaction.Commit(0);
+      }
+      else
+      {
+        transaction.Rollback();
+        errorDictionary_.LogError(code, true);
+        throw OrthancException(static_cast<ErrorCode>(code));
+      }
+    }
+  }
+
+
+  void OrthancPluginDatabase::AnswerReceived(const _OrthancPluginDatabaseAnswer& answer)
+  {
+    if (answer.type == _OrthancPluginDatabaseAnswerType_None)
+    {
+      throw OrthancException(ErrorCode_DatabasePlugin);
+    }
+
+    if (answer.type == _OrthancPluginDatabaseAnswerType_DeletedAttachment ||
+        answer.type == _OrthancPluginDatabaseAnswerType_DeletedResource ||
+        answer.type == _OrthancPluginDatabaseAnswerType_RemainingAncestor)
+    {
+      assert(listener_ != NULL);
+      ProcessEvent(*listener_, answer);
+      return;
+    }
+
+    if (type_ == _OrthancPluginDatabaseAnswerType_None)
+    {
+      type_ = answer.type;
+
+      switch (type_)
+      {
+        case _OrthancPluginDatabaseAnswerType_Int32:
+          answerInt32_.clear();
+          break;
+
+        case _OrthancPluginDatabaseAnswerType_Int64:
+          answerInt64_.clear();
+          break;
+
+        case _OrthancPluginDatabaseAnswerType_Resource:
+          answerResources_.clear();
+          break;
+
+        case _OrthancPluginDatabaseAnswerType_Attachment:
+          answerAttachments_.clear();
+          break;
+
+        case _OrthancPluginDatabaseAnswerType_String:
+          answerStrings_.clear();
+          break;
+
+        case _OrthancPluginDatabaseAnswerType_DicomTag:
+          assert(answerDicomMap_ != NULL);
+          answerDicomMap_->Clear();
+          break;
+
+        case _OrthancPluginDatabaseAnswerType_Change:
+          assert(answerChanges_ != NULL);
+          answerChanges_->clear();
+          break;
+
+        case _OrthancPluginDatabaseAnswerType_ExportedResource:
+          assert(answerExportedResources_ != NULL);
+          answerExportedResources_->clear();
+          break;
+
+        case _OrthancPluginDatabaseAnswerType_MatchingResource:
+          assert(answerMatchingResources_ != NULL);
+          answerMatchingResources_->clear();
+
+          if (answerMatchingInstances_ != NULL)
+          {
+            answerMatchingInstances_->clear();
+          }
+          
+          break;
+
+        case _OrthancPluginDatabaseAnswerType_Metadata:
+          assert(answerMetadata_ != NULL);
+          answerMetadata_->clear();
+          break;
+
+        default:
+          throw OrthancException(ErrorCode_DatabasePlugin,
+                                 "Unhandled type of answer for custom index plugin: " +
+                                 boost::lexical_cast<std::string>(answer.type));
+      }
+    }
+    else if (type_ != answer.type)
+    {
+      throw OrthancException(ErrorCode_DatabasePlugin,
+                             "Error in the plugin protocol: Cannot change the answer type");
+    }
+
+    switch (answer.type)
+    {
+      case _OrthancPluginDatabaseAnswerType_Int32:
+      {
+        answerInt32_.push_back(answer.valueInt32);
+        break;
+      }
+
+      case _OrthancPluginDatabaseAnswerType_Int64:
+      {
+        answerInt64_.push_back(answer.valueInt64);
+        break;
+      }
+
+      case _OrthancPluginDatabaseAnswerType_Resource:
+      {
+        OrthancPluginResourceType type = static_cast<OrthancPluginResourceType>(answer.valueInt32);
+        answerResources_.push_back(std::make_pair(answer.valueInt64, Plugins::Convert(type)));
+        break;
+      }
+
+      case _OrthancPluginDatabaseAnswerType_Attachment:
+      {
+        const OrthancPluginAttachment& attachment = 
+          *reinterpret_cast<const OrthancPluginAttachment*>(answer.valueGeneric);
+
+        answerAttachments_.push_back(Convert(attachment));
+        break;
+      }
+
+      case _OrthancPluginDatabaseAnswerType_DicomTag:
+      {
+        const OrthancPluginDicomTag& tag = *reinterpret_cast<const OrthancPluginDicomTag*>(answer.valueGeneric);
+        assert(answerDicomMap_ != NULL);
+        answerDicomMap_->SetValue(tag.group, tag.element, std::string(tag.value), false);
+        break;
+      }
+
+      case _OrthancPluginDatabaseAnswerType_String:
+      {
+        if (answer.valueString == NULL)
+        {
+          throw OrthancException(ErrorCode_DatabasePlugin);
+        }
+
+        if (type_ == _OrthancPluginDatabaseAnswerType_None)
+        {
+          type_ = _OrthancPluginDatabaseAnswerType_String;
+          answerStrings_.clear();
+        }
+        else if (type_ != _OrthancPluginDatabaseAnswerType_String)
+        {
+          throw OrthancException(ErrorCode_DatabasePlugin);
+        }
+
+        answerStrings_.push_back(std::string(answer.valueString));
+        break;
+      }
+
+      case _OrthancPluginDatabaseAnswerType_Change:
+      {
+        assert(answerDone_ != NULL);
+        if (answer.valueUint32 == 1)
+        {
+          *answerDone_ = true;
+        }
+        else if (*answerDone_)
+        {
+          throw OrthancException(ErrorCode_DatabasePlugin);
+        }
+        else
+        {
+          const OrthancPluginChange& change =
+            *reinterpret_cast<const OrthancPluginChange*>(answer.valueGeneric);
+          assert(answerChanges_ != NULL);
+          answerChanges_->push_back
+            (ServerIndexChange(change.seq,
+                               static_cast<ChangeType>(change.changeType),
+                               Plugins::Convert(change.resourceType),
+                               change.publicId,
+                               change.date));                                   
+        }
+
+        break;
+      }
+
+      case _OrthancPluginDatabaseAnswerType_ExportedResource:
+      {
+        assert(answerDone_ != NULL);
+        if (answer.valueUint32 == 1)
+        {
+          *answerDone_ = true;
+        }
+        else if (*answerDone_)
+        {
+          throw OrthancException(ErrorCode_DatabasePlugin);
+        }
+        else
+        {
+          const OrthancPluginExportedResource& exported = 
+            *reinterpret_cast<const OrthancPluginExportedResource*>(answer.valueGeneric);
+          assert(answerExportedResources_ != NULL);
+          answerExportedResources_->push_back
+            (ExportedResource(exported.seq,
+                              Plugins::Convert(exported.resourceType),
+                              exported.publicId,
+                              exported.modality,
+                              exported.date,
+                              exported.patientId,
+                              exported.studyInstanceUid,
+                              exported.seriesInstanceUid,
+                              exported.sopInstanceUid));
+        }
+
+        break;
+      }
+
+      case _OrthancPluginDatabaseAnswerType_MatchingResource:
+      {
+        const OrthancPluginMatchingResource& match = 
+          *reinterpret_cast<const OrthancPluginMatchingResource*>(answer.valueGeneric);
+
+        if (match.resourceId == NULL)
+        {
+          throw OrthancException(ErrorCode_DatabasePlugin);
+        }
+
+        assert(answerMatchingResources_ != NULL);
+        answerMatchingResources_->push_back(match.resourceId);
+
+        if (answerMatchingInstances_ != NULL)
+        {
+          if (match.someInstanceId == NULL)
+          {
+            throw OrthancException(ErrorCode_DatabasePlugin);
+          }
+
+          answerMatchingInstances_->push_back(match.someInstanceId);
+        }
+ 
+        break;
+      }
+
+      case _OrthancPluginDatabaseAnswerType_Metadata:
+      {
+        const OrthancPluginResourcesContentMetadata& metadata =
+          *reinterpret_cast<const OrthancPluginResourcesContentMetadata*>(answer.valueGeneric);
+
+        MetadataType type = static_cast<MetadataType>(metadata.metadata);
+
+        if (metadata.value == NULL)
+        {
+          throw OrthancException(ErrorCode_DatabasePlugin);
+        }
+
+        assert(answerMetadata_ != NULL &&
+               answerMetadata_->find(type) == answerMetadata_->end());
+        (*answerMetadata_) [type] = metadata.value;
+        break;
+      }
+
+      default:
+        throw OrthancException(ErrorCode_DatabasePlugin,
+                               "Unhandled type of answer for custom index plugin: " +
+                               boost::lexical_cast<std::string>(answer.type));
+    }
+  }
+
+    
+  bool OrthancPluginDatabase::IsDiskSizeAbove(uint64_t threshold)
+  {
+    if (fastGetTotalSize_)
+    {
+      return GetTotalCompressedSize() > threshold;
+    }
+    else
+    {
+      assert(GetTotalCompressedSize() == currentDiskSize_);
+      return currentDiskSize_ > threshold;
+    }      
+  }
+
+
+  void OrthancPluginDatabase::ApplyLookupResources(std::list<std::string>& resourcesId,
+                                                   std::list<std::string>* instancesId,
+                                                   const std::vector<DatabaseConstraint>& lookup,
+                                                   ResourceType queryLevel,
+                                                   size_t limit)
+  {
+    if (extensions_.lookupResources == NULL)
+    {
+      // Fallback to compatibility mode
+      ILookupResources::Apply
+        (*this, *this, resourcesId, instancesId, lookup, queryLevel, limit);
+    }
+    else
+    {
+      std::vector<OrthancPluginDatabaseConstraint> constraints;
+      std::vector< std::vector<const char*> > constraintsValues;
+
+      constraints.resize(lookup.size());
+      constraintsValues.resize(lookup.size());
+
+      for (size_t i = 0; i < lookup.size(); i++)
+      {
+        lookup[i].EncodeForPlugins(constraints[i], constraintsValues[i]);
+      }
+
+      ResetAnswers();
+      answerMatchingResources_ = &resourcesId;
+      answerMatchingInstances_ = instancesId;
+      
+      CheckSuccess(extensions_.lookupResources(GetContext(), payload_, lookup.size(),
+                                               (lookup.empty() ? NULL : &constraints[0]),
+                                               Plugins::Convert(queryLevel),
+                                               limit, (instancesId == NULL ? 0 : 1)));
+    }
+  }
+
+
+  bool OrthancPluginDatabase::CreateInstance(
+    IDatabaseWrapper::CreateInstanceResult& result,
+    int64_t& instanceId,
+    const std::string& patient,
+    const std::string& study,
+    const std::string& series,
+    const std::string& instance)
+  {
+    if (extensions_.createInstance == NULL)
+    {
+      // Fallback to compatibility mode
+      return ICreateInstance::Apply
+        (*this, result, instanceId, patient, study, series, instance);
+    }
+    else
+    {
+      OrthancPluginCreateInstanceResult output;
+      memset(&output, 0, sizeof(output));
+
+      CheckSuccess(extensions_.createInstance(&output, payload_, patient.c_str(),
+                                              study.c_str(), series.c_str(), instance.c_str()));
+
+      instanceId = output.instanceId;
+      
+      if (output.isNewInstance)
+      {
+        result.isNewPatient_ = output.isNewPatient;
+        result.isNewStudy_ = output.isNewStudy;
+        result.isNewSeries_ = output.isNewSeries;
+        result.patientId_ = output.patientId;
+        result.studyId_ = output.studyId;
+        result.seriesId_ = output.seriesId;
+        return true;
+      }
+      else
+      {
+        return false;
+      }
+    }
+  }
+
+
+  void OrthancPluginDatabase::LookupIdentifier(std::list<int64_t>& result,
+                                               ResourceType level,
+                                               const DicomTag& tag,
+                                               Compatibility::IdentifierConstraintType type,
+                                               const std::string& value)
+  {
+    if (extensions_.lookupIdentifier3 == NULL)
+    {
+      throw OrthancException(ErrorCode_DatabasePlugin,
+                             "The database plugin does not implement the mandatory LookupIdentifier3() extension");
+    }
+
+    OrthancPluginDicomTag tmp;
+    tmp.group = tag.GetGroup();
+    tmp.element = tag.GetElement();
+    tmp.value = value.c_str();
+
+    ResetAnswers();
+    CheckSuccess(extensions_.lookupIdentifier3(GetContext(), payload_, Plugins::Convert(level),
+                                               &tmp, Compatibility::Convert(type)));
+    ForwardAnswers(result);
+  }
+
+
+  void OrthancPluginDatabase::LookupIdentifierRange(std::list<int64_t>& result,
+                                                    ResourceType level,
+                                                    const DicomTag& tag,
+                                                    const std::string& start,
+                                                    const std::string& end)
+  {
+    if (extensions_.lookupIdentifierRange == NULL)
+    {
+      // Default implementation, for plugins using Orthanc SDK <= 1.3.2
+
+      LookupIdentifier(result, level, tag, Compatibility::IdentifierConstraintType_GreaterOrEqual, start);
+
+      std::list<int64_t> b;
+      LookupIdentifier(result, level, tag, Compatibility::IdentifierConstraintType_SmallerOrEqual, end);
+
+      result.splice(result.end(), b);
+    }
+    else
+    {
+      ResetAnswers();
+      CheckSuccess(extensions_.lookupIdentifierRange(GetContext(), payload_, Plugins::Convert(level),
+                                                     tag.GetGroup(), tag.GetElement(),
+                                                     start.c_str(), end.c_str()));
+      ForwardAnswers(result);
+    }
+  }
+
+
+  void OrthancPluginDatabase::SetResourcesContent(const Orthanc::ResourcesContent& content)
+  {
+    if (extensions_.setResourcesContent == NULL)
+    {
+      ISetResourcesContent::Apply(*this, content);
+    }
+    else
+    {
+      std::vector<OrthancPluginResourcesContentTags> identifierTags;
+      std::vector<OrthancPluginResourcesContentTags> mainDicomTags;
+      std::vector<OrthancPluginResourcesContentMetadata> metadata;
+
+      identifierTags.reserve(content.GetListTags().size());
+      mainDicomTags.reserve(content.GetListTags().size());
+      metadata.reserve(content.GetListMetadata().size());
+
+      for (ResourcesContent::ListTags::const_iterator
+             it = content.GetListTags().begin(); it != content.GetListTags().end(); ++it)
+      {
+        OrthancPluginResourcesContentTags tmp;
+        tmp.resource = it->resourceId_;
+        tmp.group = it->tag_.GetGroup();
+        tmp.element = it->tag_.GetElement();
+        tmp.value = it->value_.c_str();
+
+        if (it->isIdentifier_)
+        {
+          identifierTags.push_back(tmp);
+        }
+        else
+        {
+          mainDicomTags.push_back(tmp);
+        }
+      }
+
+      for (ResourcesContent::ListMetadata::const_iterator
+             it = content.GetListMetadata().begin(); it != content.GetListMetadata().end(); ++it)
+      {
+        OrthancPluginResourcesContentMetadata tmp;
+        tmp.resource = it->resourceId_;
+        tmp.metadata = it->metadata_;
+        tmp.value = it->value_.c_str();
+        metadata.push_back(tmp);
+      }
+
+      assert(identifierTags.size() + mainDicomTags.size() == content.GetListTags().size() &&
+             metadata.size() == content.GetListMetadata().size());
+       
+      CheckSuccess(extensions_.setResourcesContent(
+                     payload_,
+                     identifierTags.size(),
+                     (identifierTags.empty() ? NULL : &identifierTags[0]),
+                     mainDicomTags.size(),
+                     (mainDicomTags.empty() ? NULL : &mainDicomTags[0]),
+                     metadata.size(),
+                     (metadata.empty() ? NULL : &metadata[0])));
+    }
+  }
+
+
+
+  void OrthancPluginDatabase::GetChildrenMetadata(std::list<std::string>& target,
+                                                  int64_t resourceId,
+                                                  MetadataType metadata)
+  {
+    if (extensions_.getChildrenMetadata == NULL)
+    {
+      IGetChildrenMetadata::Apply(*this, target, resourceId, metadata);
+    }
+    else
+    {
+      ResetAnswers();
+      CheckSuccess(extensions_.getChildrenMetadata
+                   (GetContext(), payload_, resourceId, static_cast<int32_t>(metadata)));
+      ForwardAnswers(target);
+    }
+  }
+
+
+  int64_t OrthancPluginDatabase::GetLastChangeIndex()
+  {
+    if (extensions_.getLastChangeIndex == NULL)
+    {
+      // This was the default behavior in Orthanc <= 1.5.1
+      // https://groups.google.com/d/msg/orthanc-users/QhzB6vxYeZ0/YxabgqpfBAAJ
+      return 0;
+    }
+    else
+    {
+      int64_t result = 0;
+      CheckSuccess(extensions_.getLastChangeIndex(&result, payload_));
+      return result;
+    }
+  }
+
+  
+  void OrthancPluginDatabase::TagMostRecentPatient(int64_t patient)
+  {
+    if (extensions_.tagMostRecentPatient != NULL)
+    {
+      CheckSuccess(extensions_.tagMostRecentPatient(payload_, patient));
+    }
+  }
+
+
+  bool OrthancPluginDatabase::LookupResourceAndParent(int64_t& id,
+                                                      ResourceType& type,
+                                                      std::string& parentPublicId,
+                                                      const std::string& publicId)
+  {
+    if (extensions_.lookupResourceAndParent == NULL)
+    {
+      return ILookupResourceAndParent::Apply(*this, id, type, parentPublicId, publicId);
+    }
+    else
+    {
+      std::list<std::string> parent;
+
+      uint8_t isExisting;
+      OrthancPluginResourceType pluginType = OrthancPluginResourceType_Patient;
+      
+      ResetAnswers();
+      CheckSuccess(extensions_.lookupResourceAndParent
+                   (GetContext(), &isExisting, &id, &pluginType, payload_, publicId.c_str()));
+      ForwardAnswers(parent);
+
+      if (isExisting)
+      {
+        type = Plugins::Convert(pluginType);
+
+        if (parent.empty())
+        {
+          if (type != ResourceType_Patient)
+          {
+            throw OrthancException(ErrorCode_DatabasePlugin);
+          }
+        }
+        else if (parent.size() == 1)
+        {
+          if ((type != ResourceType_Study &&
+               type != ResourceType_Series &&
+               type != ResourceType_Instance) ||
+              parent.front().empty())
+          {
+            throw OrthancException(ErrorCode_DatabasePlugin);
+          }
+
+          parentPublicId = parent.front();
+        }
+        else
+        {
+          throw OrthancException(ErrorCode_DatabasePlugin);
+        }
+
+        return true;
+      }
+      else
+      {
+        return false;
+      }
+    }
+  }
+}