From 66b0a5784df4aeb62284c2421b46a80213f3d112 Mon Sep 17 00:00:00 2001
From: Jonathan Leibiusky <ionathan@gmail.com>
Date: Wed, 11 May 2011 19:45:07 -0300
Subject: [PATCH] fix md5 hashing as MessageDigest is not threadsafe, now using
 ThreadLocal

---
 src/main/java/redis/clients/util/Hashing.java | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/src/main/java/redis/clients/util/Hashing.java b/src/main/java/redis/clients/util/Hashing.java
index 3323347..1460f03 100644
--- a/src/main/java/redis/clients/util/Hashing.java
+++ b/src/main/java/redis/clients/util/Hashing.java
@@ -5,23 +5,22 @@ import java.security.NoSuchAlgorithmException;
 
 public interface Hashing {
     public static final Hashing MURMUR_HASH = new MurmurHash();
+    public ThreadLocal<MessageDigest> md5Holder = new ThreadLocal<MessageDigest>();
 
     public static final Hashing MD5 = new Hashing() {
-        private MessageDigest md5 = null; // avoid recurring construction
-
         public long hash(String key) {
             return hash(SafeEncoder.encode(key));
         }
 
         public long hash(byte[] key) {
-            if (md5 == null) {
-                try {
-                    md5 = MessageDigest.getInstance("MD5");
-                } catch (NoSuchAlgorithmException e) {
-                    throw new IllegalStateException(
-                            "++++ no md5 algorythm found");
+            try {
+                if (md5Holder.get() == null) {
+                    md5Holder.set(MessageDigest.getInstance("MD5"));
                 }
+            } catch (NoSuchAlgorithmException e) {
+                throw new IllegalStateException("++++ no md5 algorythm found");
             }
+            MessageDigest md5 = md5Holder.get();
 
             md5.reset();
             md5.update(key);