1 files changed, 54 insertions, 0 deletions
diff --git a/src/org/tukaani/xz/check/CRC64.java b/src/org/tukaani/xz/check/CRC64.java
new file mode 100644
index 0000000..02b15b7
--- /dev/null
+++ b/src/org/tukaani/xz/check/CRC64.java
@@ -0,0 +1,54 @@
+/*
+ * CRC64
+ *
+ * Author: Lasse Collin <lasse.collin@tukaani.org>
+ *
+ * This file has been put into the public domain.
+ * You can do whatever you want with this file.
+ */
+
+package org.tukaani.xz.check;
+
+public class CRC64 extends Check {
+    private static final long poly = 0xC96C5795D7870F42L;
+    private static final long[] crcTable = new long[256];
+
+    private long crc = -1;
+
+    static {
+        for (int b = 0; b < crcTable.length; ++b) {
+                long r = b;
+                for (int i = 0; i < 8; ++i) {
+                        if ((r & 1) == 1)
+                                r = (r >>> 1) ^ poly;
+                        else
+                                r >>>= 1;
+                }
+
+                crcTable[b] = r;
+        }
+    }
+
+    public CRC64() {
+        size = 8;
+        name = "CRC64";
+    }
+
+    public void update(byte[] buf, int off, int len) {
+        int end = off + len;
+
+        while (off < end)
+            crc = crcTable[(buf[off++] ^ (int)crc) & 0xFF] ^ (crc >>> 8);
+    }
+
+    public byte[] finish() {
+        long value = ~crc;
+        crc = -1;
+
+        byte[] buf = new byte[8];
+        for (int i = 0; i < buf.length; ++i)
+            buf[i] = (byte)(value >> (i * 8));
+
+        return buf;
+    }
+}