1 files changed, 99 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/checksum/crc32-zlib.cpp b/src/VBox/Runtime/common/checksum/crc32-zlib.cpp
new file mode 100644
index 00000000..0b41b28d
--- /dev/null
+++ b/src/VBox/Runtime/common/checksum/crc32-zlib.cpp
@@ -0,0 +1,99 @@
+/* $Id: crc32-zlib.cpp $ */
+/** @file
+ * IPRT - CRC-32 on top of zlib (very fast).
+ */
+
+/*
+ * Copyright (C) 2009-2023 Oracle and/or its affiliates.
+ *
+ * This file is part of VirtualBox base platform packages, as
+ * available from https://www.virtualbox.org.
+ *
+ * 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, in version 3 of the
+ * License.
+ *
+ * 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 <https://www.gnu.org/licenses>.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
+ * in the VirtualBox distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ *
+ * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
+ */
+
+
+/*********************************************************************************************************************************
+*   Header Files                                                                                                                 *
+*********************************************************************************************************************************/
+#include "internal/iprt.h"
+#include <iprt/crc.h>
+
+#include <zlib.h>
+
+/** @todo Check if we can't just use the zlib code directly here. */
+
+/**
+ * Deal with blocks that are too big for the uInt type.
+ */
+static uint32_t rtCrc32ProcessTooBig(uint32_t uCRC32, const void *pv, size_t cb)
+{
+    const Bytef *pb = (const Bytef *)pv;
+    do
+    {
+        uInt const cbChunk = cb <= ~(uInt)0 ? (uInt)cb : ~(uInt)0;
+        uCRC32 = crc32(uCRC32, pb, cbChunk);
+        pb += cbChunk;
+        cb -= cbChunk;
+    } while (!cb);
+    return uCRC32;
+}
+
+RTDECL(uint32_t) RTCrc32(const void *pv, size_t cb)
+{
+    uint32_t uCrc = crc32(0, NULL, 0);
+    if (RT_UNLIKELY((uInt)cb == cb))
+        uCrc = crc32(uCrc, (const Bytef *)pv, (uInt)cb);
+    else
+        uCrc = rtCrc32ProcessTooBig(uCrc, pv, cb);
+    return uCrc;
+}
+RT_EXPORT_SYMBOL(RTCrc32);
+
+
+RTDECL(uint32_t) RTCrc32Start(void)
+{
+    return crc32(0, NULL, 0);
+}
+RT_EXPORT_SYMBOL(RTCrc32Start);
+
+
+RTDECL(uint32_t) RTCrc32Process(uint32_t uCRC32, const void *pv, size_t cb)
+{
+    if (RT_UNLIKELY((uInt)cb == cb))
+        uCRC32 = crc32(uCRC32, (const Bytef *)pv, (uInt)cb);
+    else
+        uCRC32 = rtCrc32ProcessTooBig(uCRC32, pv, cb);
+    return uCRC32;
+}
+RT_EXPORT_SYMBOL(RTCrc32Process);
+
+
+RTDECL(uint32_t) RTCrc32Finish(uint32_t uCRC32)
+{
+    return uCRC32;
+}
+RT_EXPORT_SYMBOL(RTCrc32Finish);
+