1 files changed, 40 insertions, 63 deletions

diff --git a/guava/src/com/google/common/hash/Murmur3_128HashFunction.java b/guava/src/com/google/common/hash/Murmur3_128HashFunction.java
index aab08a3..cd49f87 100644
--- a/guava/src/com/google/common/hash/Murmur3_128HashFunction.java
+++ b/guava/src/com/google/common/hash/Murmur3_128HashFunction.java
@@ -12,17 +12,6 @@
  * the License.
  */
 
-/*
- * MurmurHash3 was written by Austin Appleby, and is placed in the public
- * domain. The author hereby disclaims copyright to this source code.
- */
-
-/*
- * Source:
- * http://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp
- * (Modified to adapt to Guava coding conventions and to use the HashFunction interface)
- */
-
 package com.google.common.hash;
 
 import static com.google.common.primitives.UnsignedBytes.toInt;
@@ -35,8 +24,8 @@ import java.nio.ByteOrder;
  * See http://smhasher.googlecode.com/svn/trunk/MurmurHash3.cpp
  * MurmurHash3_x64_128
  *
- * @author Austin Appleby
- * @author Dimitris Andreou
+ * @author aappleby@google.com (Austin Appleby)
+ * @author andreou@google.com (Dimitris Andreou)
  */
 final class Murmur3_128HashFunction extends AbstractStreamingHashFunction implements Serializable {
   // TODO(user): when the shortcuts are implemented, update BloomFilterStrategies
@@ -54,41 +43,40 @@ final class Murmur3_128HashFunction extends AbstractStreamingHashFunction implem
     return new Murmur3_128Hasher(seed);
   }
 
-  @Override
-  public String toString() {
-    return "Hashing.murmur3_128(" + seed + ")";
-  }
-
   private static final class Murmur3_128Hasher extends AbstractStreamingHasher {
-    private static final int CHUNK_SIZE = 16;
-    private static final long C1 = 0x87c37b91114253d5L;
-    private static final long C2 = 0x4cf5ad432745937fL;
-    private long h1;
-    private long h2;
-    private int length;
+    long h1;
+    long h2;
+    long c1 = 0x87c37b91114253d5L;
+    long c2 = 0x4cf5ad432745937fL;
+    int len;
 
     Murmur3_128Hasher(int seed) {
-      super(CHUNK_SIZE);
-      this.h1 = seed;
-      this.h2 = seed;
-      this.length = 0;
+      super(16);
+      h1 = seed;
+      h2 = seed;
     }
 
     @Override protected void process(ByteBuffer bb) {
       long k1 = bb.getLong();
       long k2 = bb.getLong();
+      len += 16;
       bmix64(k1, k2);
-      length += CHUNK_SIZE;
     }
 
     private void bmix64(long k1, long k2) {
-      h1 ^= mixK1(k1);
+      k1 *= c1;
+      k1 = Long.rotateLeft(k1, 31);
+      k1 *= c2;
+      h1 ^= k1;
 
       h1 = Long.rotateLeft(h1, 27);
       h1 += h2;
       h1 = h1 * 5 + 0x52dce729;
 
-      h2 ^= mixK2(k2);
+      k2 *= c2;
+      k2 = Long.rotateLeft(k2, 33);
+      k2 *= c1;
+      h2 ^= k2;
 
       h2 = Long.rotateLeft(h2, 31);
       h2 += h1;
@@ -98,7 +86,7 @@ final class Murmur3_128HashFunction extends AbstractStreamingHashFunction implem
     @Override protected void processRemaining(ByteBuffer bb) {
       long k1 = 0;
       long k2 = 0;
-      length += bb.remaining();
+      len += bb.remaining();
       switch (bb.remaining()) {
         case 15:
           k2 ^= (long) toInt(bb.get(14)) << 48; // fall through
@@ -113,10 +101,14 @@ final class Murmur3_128HashFunction extends AbstractStreamingHashFunction implem
         case 10:
           k2 ^= (long) toInt(bb.get(9)) << 8; // fall through
         case 9:
-          k2 ^= (long) toInt(bb.get(8)); // fall through
+          k2 ^= (long) toInt(bb.get(8)) << 0;
+          k2 *= c2;
+          k2 = Long.rotateLeft(k2, 33);
+          k2 *= c1;
+          h2 ^= k2;
+          // fall through
         case 8:
-          k1 ^= bb.getLong();
-          break;
+          k1 ^= (long) toInt(bb.get(7)) << 56; // fall through
         case 7:
           k1 ^= (long) toInt(bb.get(6)) << 48; // fall through
         case 6:
@@ -130,18 +122,19 @@ final class Murmur3_128HashFunction extends AbstractStreamingHashFunction implem
         case 2:
           k1 ^= (long) toInt(bb.get(1)) << 8; // fall through
         case 1:
-          k1 ^= (long) toInt(bb.get(0));
-          break;
+          k1 ^= (long) toInt(bb.get(0)) << 0;
+          k1 *= c1;
+          k1 = Long.rotateLeft(k1, 31);
+          k1 *= c2;
+          h1 ^= k1;
+          // fall through
         default:
-          throw new AssertionError("Should never get here.");
       }
-      h1 ^= mixK1(k1);
-      h2 ^= mixK2(k2);
     }
 
     @Override public HashCode makeHash() {
-      h1 ^= length;
-      h2 ^= length;
+      h1 ^= len;
+      h2 ^= len;
 
       h1 += h2;
       h2 += h1;
@@ -152,15 +145,13 @@ final class Murmur3_128HashFunction extends AbstractStreamingHashFunction implem
       h1 += h2;
       h2 += h1;
 
-      return HashCodes.fromBytesNoCopy(ByteBuffer
-          .wrap(new byte[CHUNK_SIZE])
-          .order(ByteOrder.LITTLE_ENDIAN)
-          .putLong(h1)
-          .putLong(h2)
-          .array());
+      ByteBuffer bb = ByteBuffer.wrap(new byte[16]).order(ByteOrder.LITTLE_ENDIAN);
+      bb.putLong(h1);
+      bb.putLong(h2);
+      return HashCodes.fromBytes(bb.array());
     }
 
-    private static long fmix64(long k) {
+    private long fmix64(long k) {
       k ^= k >>> 33;
       k *= 0xff51afd7ed558ccdL;
       k ^= k >>> 33;
@@ -168,20 +159,6 @@ final class Murmur3_128HashFunction extends AbstractStreamingHashFunction implem
       k ^= k >>> 33;
       return k;
     }
-
-    private static long mixK1(long k1) {
-      k1 *= C1;
-      k1 = Long.rotateLeft(k1, 31);
-      k1 *= C2;
-      return k1;
-    }
-
-    private static long mixK2(long k2) {
-      k2 *= C2;
-      k2 = Long.rotateLeft(k2, 33);
-      k2 *= C1;
-      return k2;
-    }
   }
 
   private static final long serialVersionUID = 0L;