1 files changed, 64 insertions, 0 deletions
diff --git a/Tools/DumpRenderTree/CyclicRedundancyCheck.cpp b/Tools/DumpRenderTree/CyclicRedundancyCheck.cpp
new file mode 100644
index 0000000..361ea0f
--- /dev/null
+++ b/Tools/DumpRenderTree/CyclicRedundancyCheck.cpp
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2010, Robert Eisele <robert@xarg.org> All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "CyclicRedundancyCheck.h"
+
+#include <wtf/Vector.h>
+
+static void makeCrcTable(unsigned crcTable[256])
+{
+    for (unsigned i = 0; i < 256; i++) {
+        unsigned c = i;
+        for (int k = 0; k < 8; k++) {
+            if (c & 1)
+                c = -306674912 ^ ((c >> 1) & 0x7fffffff);
+            else
+                c = c >> 1;
+        }
+        crcTable[i] = c;
+    }
+}
+
+unsigned computeCrc(const Vector<unsigned char>& buffer)
+{
+    static unsigned crcTable[256];
+    static bool crcTableComputed = false;
+    if (!crcTableComputed) {
+        makeCrcTable(crcTable);
+        crcTableComputed = true;
+    }
+
+    unsigned crc = 0xffffffffL;
+    for (size_t i = 0; i < buffer.size(); ++i)
+        crc = crcTable[(crc ^ buffer[i]) & 0xff] ^ ((crc >> 8) & 0x00ffffffL);
+    return crc ^ 0xffffffffL;
+}
+