1 files changed, 75 insertions, 0 deletions
diff --git a/vcl/inc/pdf/ExternalPDFStreams.hxx b/vcl/inc/pdf/ExternalPDFStreams.hxx
new file mode 100644
index 000000000..45b15f7a7
--- /dev/null
+++ b/vcl/inc/pdf/ExternalPDFStreams.hxx
@@ -0,0 +1,75 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#pragma once
+
+#include <sal/types.h>
+#include <sal/log.hxx>
+#include <vcl/dllapi.h>
+
+#include <map>
+#include <vector>
+#include <memory>
+
+#include <vcl/filter/pdfdocument.hxx>
+#include <vcl/BinaryDataContainer.hxx>
+
+namespace vcl
+{
+// A external PDF stream, which stores the PDF stream data as byte array.
+// This struct is also responsible to parsing the stream as a PDFDocument,
+// and store its instance for the life-cycle of the struct, so that it
+// reused to avoid unnecessary parsing.
+struct VCL_DLLPUBLIC ExternalPDFStream
+{
+    BinaryDataContainer maDataContainer;
+    std::shared_ptr<filter::PDFDocument> mpPDFDocument;
+    std::map<sal_Int32, sal_Int32> maCopiedResources;
+
+    std::map<sal_Int32, sal_Int32>& getCopiedResources() { return maCopiedResources; }
+
+    std::shared_ptr<filter::PDFDocument>& getPDFDocument()
+    {
+        if (!mpPDFDocument)
+        {
+            SvMemoryStream aPDFStream;
+            aPDFStream.WriteBytes(maDataContainer.getData(), maDataContainer.getSize());
+            aPDFStream.Seek(0);
+            auto pPDFDocument = std::make_shared<filter::PDFDocument>();
+            if (!pPDFDocument->ReadWithPossibleFixup(aPDFStream))
+            {
+                SAL_WARN("vcl.pdfwriter",
+                         "PDFWriterImpl::writeReferenceXObject: reading the PDF document failed");
+            }
+            else
+            {
+                mpPDFDocument = pPDFDocument;
+            }
+        }
+        return mpPDFDocument;
+    }
+};
+
+// Class to manage external PDF streams, for the de-duplication purpose.
+class ExternalPDFStreams
+{
+private:
+    std::map<std::vector<sal_uInt8>, sal_Int32> maStreamIndexMap;
+    std::vector<ExternalPDFStream> maStreamList;
+
+public:
+    ExternalPDFStreams() {}
+
+    sal_Int32 store(BinaryDataContainer const& rDataContainer);
+
+    ExternalPDFStream& get(sal_uInt32 nIndex);
+};
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */