--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancFramework/Sources/DicomFormat/StreamBlockReader.cpp	Wed Sep 30 15:33:47 2020 +0200
@@ -0,0 +1,88 @@
+/**
+ * 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 Lesser 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program. If not, see
+ * <http://www.gnu.org/licenses/>.
+ **/
+
+
+#include "../PrecompiledHeaders.h"
+#include "StreamBlockReader.h"
+
+#include "../OrthancException.h"
+
+
+namespace Orthanc
+{
+  StreamBlockReader::StreamBlockReader(std::istream& stream) :
+    stream_(stream),
+    blockPos_(0),
+    processedBytes_(0)
+  {
+  }
+
+
+  void StreamBlockReader::Schedule(size_t blockSize)
+  {
+    if (!block_.empty())
+    {
+      throw OrthancException(ErrorCode_BadSequenceOfCalls);
+    }
+    else
+    {
+      block_.resize(blockSize);
+      blockPos_ = 0;
+    }
+  }
+
+
+  bool StreamBlockReader::Read(std::string& block)
+  {
+    if (block_.empty())
+    {
+      if (blockPos_ != 0)
+      {
+        throw OrthancException(ErrorCode_BadSequenceOfCalls);
+      }
+        
+      block.clear();
+      return true;
+    }
+    else
+    {
+      while (blockPos_ < block_.size())
+      {
+        size_t remainingBytes = block_.size() - blockPos_;
+        std::streamsize r = stream_.readsome(&block_[blockPos_], remainingBytes);
+        if (r == 0)
+        {
+          return false;
+        }
+        else
+        {
+          blockPos_ += r;
+        }
+      }
+
+      processedBytes_ += block_.size();
+
+      block.swap(block_);
+      block_.clear();
+      return true;
+    }
+  }
+}