--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancFramework/Sources/DicomFormat/StreamBlockReader.h	Wed Sep 30 15:33:47 2020 +0200
@@ -0,0 +1,66 @@
+/**
+ * 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/>.
+ **/
+
+
+#pragma once
+
+#include <boost/noncopyable.hpp>
+#include <istream>
+#include <string>
+
+
+namespace Orthanc
+{
+  /**
+   * This class is used to extract blocks of given size from a
+   * stream. Bytes from the stream are buffered until the requested
+   * size is available, and the full block can be returned.
+   **/
+  class StreamBlockReader : public boost::noncopyable
+  {
+  private:
+    std::istream&  stream_;
+    std::string    block_;
+    size_t         blockPos_;
+    uint64_t       processedBytes_;
+
+  public:
+    StreamBlockReader(std::istream& stream);
+
+    /**
+     * Schedule the size of the next block to be extracted from the
+     * stream.
+     **/
+    void Schedule(size_t blockSize);
+
+    /**
+     * Extract the block whose size was configured by the previous
+     * call to "Schedule()". Returns "false" iff not enough bytes are
+     * available from the stream yet: In this case, try again later.
+     **/
+    bool Read(std::string& block);
+    
+    uint64_t GetProcessedBytes() const
+    {
+      return processedBytes_;
+    }
+  };
+}