--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancFramework/Sources/Compression/ZlibCompressor.cpp	Wed Jun 10 20:30:34 2020 +0200
@@ -0,0 +1,160 @@
+/**
+ * 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 "../PrecompiledHeaders.h"
+#include "ZlibCompressor.h"
+
+#include "../OrthancException.h"
+#include "../Logging.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <zlib.h>
+
+namespace Orthanc
+{
+  void ZlibCompressor::Compress(std::string& compressed,
+                                const void* uncompressed,
+                                size_t uncompressedSize)
+  {
+    if (uncompressedSize == 0)
+    {
+      compressed.clear();
+      return;
+    }
+
+    uLongf compressedSize = compressBound(static_cast<uLong>(uncompressedSize))
+      + 1024 /* security margin */;
+    if (compressedSize == 0)
+    {
+      compressedSize = 1;
+    }
+
+    uint8_t* target;
+    if (HasPrefixWithUncompressedSize())
+    {
+      compressed.resize(compressedSize + sizeof(uint64_t));
+      target = reinterpret_cast<uint8_t*>(&compressed[0]) + sizeof(uint64_t);
+    }
+    else
+    {
+      compressed.resize(compressedSize);
+      target = reinterpret_cast<uint8_t*>(&compressed[0]);
+    }
+
+    int error = compress2(target,
+                          &compressedSize,
+                          const_cast<Bytef *>(static_cast<const Bytef *>(uncompressed)), 
+                          static_cast<uLong>(uncompressedSize),
+                          GetCompressionLevel());
+
+    if (error != Z_OK)
+    {
+      compressed.clear();
+
+      switch (error)
+      {
+      case Z_MEM_ERROR:
+        throw OrthancException(ErrorCode_NotEnoughMemory);
+
+      default:
+        throw OrthancException(ErrorCode_InternalError);
+      }  
+    }
+
+    // The compression was successful
+    if (HasPrefixWithUncompressedSize())
+    {
+      uint64_t s = static_cast<uint64_t>(uncompressedSize);
+      memcpy(&compressed[0], &s, sizeof(uint64_t));
+      compressed.resize(compressedSize + sizeof(uint64_t));
+    }
+    else
+    {
+      compressed.resize(compressedSize);
+    }
+  }
+
+
+  void ZlibCompressor::Uncompress(std::string& uncompressed,
+                                  const void* compressed,
+                                  size_t compressedSize)
+  {
+    if (compressedSize == 0)
+    {
+      uncompressed.clear();
+      return;
+    }
+
+    if (!HasPrefixWithUncompressedSize())
+    {
+      throw OrthancException(ErrorCode_InternalError,
+                             "Cannot guess the uncompressed size of a zlib-encoded buffer");
+    }
+
+    uint64_t uncompressedSize = ReadUncompressedSizePrefix(compressed, compressedSize);
+    
+    try
+    {
+      uncompressed.resize(static_cast<size_t>(uncompressedSize));
+    }
+    catch (...)
+    {
+      throw OrthancException(ErrorCode_NotEnoughMemory);
+    }
+
+    uLongf tmp = static_cast<uLongf>(uncompressedSize);
+    int error = uncompress
+      (reinterpret_cast<uint8_t*>(&uncompressed[0]), 
+       &tmp,
+       reinterpret_cast<const uint8_t*>(compressed) + sizeof(uint64_t),
+        static_cast<uLong>(compressedSize - sizeof(uint64_t)));
+
+    if (error != Z_OK)
+    {
+      uncompressed.clear();
+
+      switch (error)
+      {
+      case Z_DATA_ERROR:
+        throw OrthancException(ErrorCode_CorruptedFile);
+
+      case Z_MEM_ERROR:
+        throw OrthancException(ErrorCode_NotEnoughMemory);
+
+      default:
+        throw OrthancException(ErrorCode_InternalError);
+      }  
+    }
+  }
+}