Added support for computing 64-bit checksum of bitmap in OpenGL

Added a C++ and a GLSL implementation of a 64-bit CRC algorithm.

Changed hardcoded checksum value in ooxmlimport unit test (testN777345).

Change-Id: I16bb985a14866775efda49e21fe033ff64645896

1 files changed, 51 insertions, 0 deletions

diff --git a/vcl/source/bitmap/checksum.cxx b/vcl/source/bitmap/checksum.cxx
new file mode 100644
index 000000000000..a46db1e75265
--- /dev/null
+++ b/vcl/source/bitmap/checksum.cxx
@@ -0,0 +1,51 @@
+/* -*- 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/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#include <sal/types.h>
+#include <checksum.hxx>
+
+/*========================================================================
+ *
+ * vcl_crc64 implementation.
+ *
+ *======================================================================*/
+#define UPDCRC64(crc, octet) \
+    (vcl_crc64Table[((crc) ^ (octet)) & 0xff] ^ ((crc) >> 8))
+
+/*
+ * rtl_crc64.
+ */
+sal_uInt64 SAL_CALL vcl_crc64 (
+    sal_uInt64  Crc,
+    const void *Data, sal_uInt32 DatLen)  SAL_THROW_EXTERN_C()
+{
+    if (Data)
+    {
+        const sal_uInt8 *p = static_cast<const sal_uInt8 *>(Data);
+        const sal_uInt8 *q = p + DatLen;
+
+        Crc = ~Crc;
+        while (p < q)
+            Crc = UPDCRC64(Crc, *(p++));
+        Crc = ~Crc;
+    }
+    return Crc;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */