--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/com/jcraft/jzlib/Adler32.java	Thu May 22 10:41:19 2014 -0700
@@ -0,0 +1,98 @@
+/* -*-mode:java; c-basic-offset:2; -*- */
+/*
+Copyright (c) 2000,2001,2002,2003 ymnk, JCraft,Inc. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+  1. Redistributions of source code must retain the above copyright notice,
+     this list of conditions and the following disclaimer.
+
+  2. 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.
+
+  3. The names of the authors may not be used to endorse or promote products
+     derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 JCRAFT,
+INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE 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.
+ */
+/*
+ * This program is based on zlib-1.1.3, so all credit should go authors
+ * Jean-loup Gailly(jloup@gzip.org) and Mark Adler(madler@alumni.caltech.edu)
+ * and contributors of zlib.
+ */
+
+package com.jcraft.jzlib;
+
+final class Adler32 {
+
+    // largest prime smaller than 65536
+    static final private int BASE = 65521;
+    // NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1
+    static final private int NMAX = 5552;
+
+    long adler32(long adler, byte[] buf, int index, int len) {
+        if (buf == null) { return 1L; }
+
+        long s1 = adler & 0xffff;
+        long s2 = (adler >> 16) & 0xffff;
+        int k;
+
+        while (len > 0) {
+            k = len < NMAX ? len : NMAX;
+            len -= k;
+
+            while (k >= 16) {
+                s1 += buf[index++] & 0xff; s2 += s1;
+                s1 += buf[index++] & 0xff; s2 += s1;
+                s1 += buf[index++] & 0xff; s2 += s1;
+                s1 += buf[index++] & 0xff; s2 += s1;
+                s1 += buf[index++] & 0xff; s2 += s1;
+                s1 += buf[index++] & 0xff; s2 += s1;
+                s1 += buf[index++] & 0xff; s2 += s1;
+                s1 += buf[index++] & 0xff; s2 += s1;
+                s1 += buf[index++] & 0xff; s2 += s1;
+                s1 += buf[index++] & 0xff; s2 += s1;
+                s1 += buf[index++] & 0xff; s2 += s1;
+                s1 += buf[index++] & 0xff; s2 += s1;
+                s1 += buf[index++] & 0xff; s2 += s1;
+                s1 += buf[index++] & 0xff; s2 += s1;
+                s1 += buf[index++] & 0xff; s2 += s1;
+                s1 += buf[index++] & 0xff; s2 += s1;
+                k -= 16;
+            }
+
+            if (k != 0) {
+                do {
+                    s1 += buf[index++] & 0xff; s2 += s1;
+                }
+                while (--k != 0);
+            }
+
+            s1 %= BASE;
+            s2 %= BASE;
+        }
+
+        return (s2 << 16) | s1;
+    }
+
+    /*
+    private java.util.zip.Adler32 adler=new java.util.zip.Adler32();
+    long adler32(long value, byte[] buf, int index, int len){
+      if(value==1) {adler.reset();}
+      if(buf==null) {adler.reset();}
+      else{adler.update(buf, index, len);}
+      return adler.getValue();
+    }
+    */
+}