--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Framework/Plugins/StorageAreaBuffer.cpp	Fri Jan 08 14:40:03 2021 +0100
@@ -0,0 +1,98 @@
+/**
+ * Orthanc - A Lightweight, RESTful DICOM Store
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2021 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 "StorageAreaBuffer.h"
+
+#include <OrthancException.h>
+
+#include <limits>
+#include <string.h>
+
+
+namespace OrthancDatabases
+{
+  StorageAreaBuffer::StorageAreaBuffer() :
+    data_(NULL),
+    size_(0)
+  {
+  }
+
+  
+  void StorageAreaBuffer::Clear()
+  {
+    if (data_ != NULL)
+    {
+      free(data_);
+      data_ = NULL;
+      size_ = 0;
+    }
+  }
+
+
+  void StorageAreaBuffer::Assign(const std::string& content)
+  {
+    Clear();
+    
+    size_ = static_cast<int64_t>(content.size());
+    
+    if (static_cast<size_t>(size_) != content.size())
+    {
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_NotEnoughMemory,
+                                      "File cannot be stored in a 63bit buffer");
+    }
+
+    if (content.empty())
+    {
+      data_ = NULL;
+    }
+    else
+    {
+      data_ = malloc(size_);
+
+      if (data_ == NULL)
+      {
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_NotEnoughMemory);
+      }
+
+      memcpy(data_, content.c_str(), size_);
+    }
+  }
+
+
+  void* StorageAreaBuffer::ReleaseData()
+  {
+    void* result = data_;
+    data_ = NULL;
+    size_ = 0;
+    return result;
+  }
+
+
+  void StorageAreaBuffer::ToString(std::string& target)
+  {
+    target.resize(size_);
+
+    if (size_ != 0)
+    {
+      memcpy(&target[0], data_, size_);
+    }
+  }
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Framework/Plugins/StorageAreaBuffer.h	Fri Jan 08 14:40:03 2021 +0100
@@ -0,0 +1,64 @@
+/**
+ * Orthanc - A Lightweight, RESTful DICOM Store
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2021 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/>.
+ **/
+
+
+#pragma once
+
+#include <orthanc/OrthancCPlugin.h>
+
+#include <boost/noncopyable.hpp>
+#include <string>
+
+
+namespace OrthancDatabases
+{
+  class StorageAreaBuffer : public boost::noncopyable
+  {
+  private:
+    void*    data_;
+    int64_t  size_;
+
+  public:
+    StorageAreaBuffer();
+
+    ~StorageAreaBuffer()
+    {
+      Clear();
+    }
+
+    void Clear();
+
+    void Assign(const std::string& content);
+
+    int64_t GetSize() const
+    {
+      return size_;
+    }
+
+    const void* GetData() const
+    {
+      return data_;
+    }
+
+    void* ReleaseData();
+
+    void ToString(std::string& target);
+  };
+}

--- a/Framework/Plugins/StorageBackend.cpp	Wed Jan 06 17:40:27 2021 +0100
+++ b/Framework/Plugins/StorageBackend.cpp	Fri Jan 08 14:40:03 2021 +0100
@@ -31,6 +31,8 @@
 #include <Compatibility.h>  // For std::unique_ptr<>
 #include <OrthancException.h>
 
+#include <limits>
+
 
 #define ORTHANC_PLUGINS_DATABASE_CATCH                                  \
   catch (::Orthanc::OrthancException& e)                                \
@@ -52,69 +54,12 @@
 
 namespace OrthancDatabases
 {
-  void StorageBackend::ReadFromString(void*& buffer,
-                                      size_t& size,
-                                      const std::string& content)
-  {
-    size = content.size();
-
-    if (content.empty())
-    {
-      buffer = NULL;
-    }
-    else
-    {
-      buffer = malloc(size);
-
-      if (buffer == NULL)
-      {
-        throw Orthanc::OrthancException(Orthanc::ErrorCode_NotEnoughMemory);
-      }
-
-      memcpy(buffer, content.c_str(), size);
-    }
-  }
-
-  
   StorageBackend::StorageBackend(IDatabaseFactory* factory) :
     manager_(factory)
   {
   }
 
 
-  void StorageBackend::ReadToString(std::string& content,
-                                    DatabaseManager::Transaction& transaction, 
-                                    const std::string& uuid,
-                                    OrthancPluginContentType type)
-  {
-    void* buffer = NULL; 
-    size_t size;
-    Read(buffer, size, transaction, uuid, type);
-
-    try
-    {
-      content.resize(size);
-    }
-    catch (std::bad_alloc&)
-    {
-      if (size != 0)
-      {
-        free(buffer);
-      }
-
-      throw Orthanc::OrthancException(Orthanc::ErrorCode_NotEnoughMemory);
-    }
-
-    if (size != 0)
-    {
-      assert(buffer != NULL);
-      memcpy(&content[0], buffer, size);
-    }
-
-    free(buffer);
-  }
-
-
   void StorageBackend::Create(DatabaseManager::Transaction& transaction,
                               const std::string& uuid,
                               const void* content,
@@ -138,8 +83,7 @@
   }
 
 
-  void StorageBackend::Read(void*& content,
-                            size_t& size,
+  void StorageBackend::Read(StorageAreaBuffer& target,
                             DatabaseManager::Transaction& transaction, 
                             const std::string& uuid,
                             OrthancPluginContentType type) 
@@ -172,13 +116,11 @@
       switch (value.GetType())
       {
         case ValueType_File:
-          ReadFromString(content, size,
-                         dynamic_cast<const FileValue&>(value).GetContent());
+          target.Assign(dynamic_cast<const FileValue&>(value).GetContent());
           break;
 
         case ValueType_BinaryString:
-          ReadFromString(content, size,
-                         dynamic_cast<const BinaryStringValue&>(value).GetContent());
+          target.Assign(dynamic_cast<const BinaryStringValue&>(value).GetContent());
           break;
 
         default:
@@ -235,11 +177,17 @@
   {
     try
     {
-      DatabaseManager::Transaction transaction(backend_->GetManager());
-      size_t tmp;
-      backend_->Read(*content, tmp, transaction, uuid, type);
-      *size = static_cast<int64_t>(tmp);
-      transaction.Commit();
+      StorageAreaBuffer buffer;
+
+      {
+        DatabaseManager::Transaction transaction(backend_->GetManager());
+        backend_->Read(buffer, transaction, uuid, type);
+        transaction.Commit();
+      }
+
+      *size = buffer.GetSize();
+      *content = buffer.ReleaseData();
+      
       return OrthancPluginErrorCode_Success;
     }
     ORTHANC_PLUGINS_DATABASE_CATCH;

--- a/Framework/Plugins/StorageBackend.h	Wed Jan 06 17:40:27 2021 +0100
+++ b/Framework/Plugins/StorageBackend.h	Fri Jan 08 14:40:03 2021 +0100
@@ -21,7 +21,9 @@
 
 #pragma once
 
+#include "StorageAreaBuffer.h"
 #include "../Common/DatabaseManager.h"
+
 #include <orthanc/OrthancCDatabasePlugin.h>
 
 
@@ -32,11 +34,6 @@
   private:
     DatabaseManager   manager_;
 
-  protected:
-    void ReadFromString(void*& buffer,
-                        size_t& size,
-                        const std::string& content);
-
   public:
     explicit StorageBackend(IDatabaseFactory* factory);
 
@@ -58,8 +55,7 @@
                         size_t size,
                         OrthancPluginContentType type);
 
-    virtual void Read(void*& content,
-                      size_t& size,
+    virtual void Read(StorageAreaBuffer& target,
                       DatabaseManager::Transaction& transaction, 
                       const std::string& uuid,
                       OrthancPluginContentType type);
@@ -71,12 +67,6 @@
     static void Register(OrthancPluginContext* context,
                          StorageBackend* backend);   // Takes ownership
 
-    // For unit testing!
-    void ReadToString(std::string& content,
-                      DatabaseManager::Transaction& transaction, 
-                      const std::string& uuid,
-                      OrthancPluginContentType type);
-
     static void Finalize();
   };
 }

--- a/MySQL/UnitTests/UnitTestsMain.cpp	Wed Jan 06 17:40:27 2021 +0100
+++ b/MySQL/UnitTests/UnitTestsMain.cpp	Fri Jan 08 14:40:03 2021 +0100
@@ -163,8 +163,8 @@
       storageArea.Create(transaction, uuid, value.c_str(), value.size(), OrthancPluginContentType_Unknown);
     }
 
-    std::string tmp;
-    ASSERT_THROW(storageArea.ReadToString(tmp, transaction, "nope", OrthancPluginContentType_Unknown), 
+    OrthancDatabases::StorageAreaBuffer buffer;
+    ASSERT_THROW(storageArea.Read(buffer, transaction, "nope", OrthancPluginContentType_Unknown), 
                  Orthanc::OrthancException);
   
     ASSERT_EQ(10, CountFiles(db));
@@ -180,13 +180,16 @@
 
       if (i == 5)
       {
-        ASSERT_THROW(storageArea.ReadToString(content, transaction, uuid, OrthancPluginContentType_Unknown), 
+        ASSERT_THROW(storageArea.Read(buffer, transaction, uuid, OrthancPluginContentType_Unknown), 
                      Orthanc::OrthancException);
       }
       else
       {
-        storageArea.ReadToString(content, transaction, uuid, OrthancPluginContentType_Unknown);
-        ASSERT_EQ(expected, content);
+        storageArea.Read(buffer, transaction, uuid, OrthancPluginContentType_Unknown);
+
+        std::string s;
+        buffer.ToString(s);
+        ASSERT_EQ(expected, s);
       }
     }
 

--- a/PostgreSQL/UnitTests/PostgreSQLTests.cpp	Wed Jan 06 17:40:27 2021 +0100
+++ b/PostgreSQL/UnitTests/PostgreSQLTests.cpp	Fri Jan 08 14:40:03 2021 +0100
@@ -356,8 +356,8 @@
       storageArea.Create(transaction, uuid, value.c_str(), value.size(), OrthancPluginContentType_Unknown);
     }
 
-    std::string tmp;
-    ASSERT_THROW(storageArea.ReadToString(tmp, transaction, "nope", OrthancPluginContentType_Unknown), 
+    StorageAreaBuffer buffer;
+    ASSERT_THROW(storageArea.Read(buffer, transaction, "nope", OrthancPluginContentType_Unknown), 
                  Orthanc::OrthancException);
   
     ASSERT_EQ(10, CountLargeObjects(db));
@@ -369,17 +369,19 @@
     {
       std::string uuid = boost::lexical_cast<std::string>(i);
       std::string expected = "Value " + boost::lexical_cast<std::string>(i * 2);
-      std::string content;
 
       if (i == 5)
       {
-        ASSERT_THROW(storageArea.ReadToString(content, transaction, uuid, OrthancPluginContentType_Unknown), 
+        ASSERT_THROW(storageArea.Read(buffer, transaction, uuid, OrthancPluginContentType_Unknown), 
                      Orthanc::OrthancException);
       }
       else
       {
-        storageArea.ReadToString(content, transaction, uuid, OrthancPluginContentType_Unknown);
-        ASSERT_EQ(expected, content);
+        storageArea.Read(buffer, transaction, uuid, OrthancPluginContentType_Unknown);
+
+        std::string s;
+        buffer.ToString(s);
+        ASSERT_EQ(expected, s);
       }
     }
 

--- a/Resources/CMake/DatabasesPluginConfiguration.cmake	Wed Jan 06 17:40:27 2021 +0100
+++ b/Resources/CMake/DatabasesPluginConfiguration.cmake	Fri Jan 08 14:40:03 2021 +0100
@@ -70,6 +70,7 @@
   ${ORTHANC_CORE_SOURCES}
   ${ORTHANC_DATABASES_ROOT}/Framework/Plugins/GlobalProperties.cpp
   ${ORTHANC_DATABASES_ROOT}/Framework/Plugins/IndexBackend.cpp
+  ${ORTHANC_DATABASES_ROOT}/Framework/Plugins/StorageAreaBuffer.cpp
   ${ORTHANC_DATABASES_ROOT}/Framework/Plugins/StorageBackend.cpp
   ${ORTHANC_DATABASES_ROOT}/Resources/Orthanc/Databases/DatabaseConstraint.cpp
   ${ORTHANC_DATABASES_ROOT}/Resources/Orthanc/Databases/ISqlLookupFormatter.cpp