From 30060b60833d099f8ebefdf8174755284f2716d8 Mon Sep 17 00:00:00 2001
From: nmittler <nmittler@gmail.com>
Date: Mon, 20 Oct 2014 10:19:54 -0700
Subject: [PATCH] Optimize IntObjectHashMap handling of negative keys.

Motivation:

The hashIndex method currently uses a conditional to handle negative
keys. This could be done without a conditional to slightly improve
performance.

Modifications:

Modified hashIndex() to avoid using a conditional.

Result:

Slight performance improvement to hashIndex().
---
 .../java/io/netty/util/collection/IntObjectHashMap.java   | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/common/src/main/java/io/netty/util/collection/IntObjectHashMap.java b/common/src/main/java/io/netty/util/collection/IntObjectHashMap.java
index 4d1cdfc78f..1a4d019e56 100644
--- a/common/src/main/java/io/netty/util/collection/IntObjectHashMap.java
+++ b/common/src/main/java/io/netty/util/collection/IntObjectHashMap.java
@@ -311,11 +311,9 @@ public class IntObjectHashMap<V> implements IntObjectMap<V>, Iterable<IntObjectM
      * Returns the hashed index for the given key.
      */
     private int hashIndex(int key) {
-        int hash = key % keys.length;
-        if (hash < 0) {
-            hash += keys.length;
-        }
-        return hash;
+        int length = keys.length;
+        // Allowing for negative keys by adding the length after the first mod operation.
+        return (key % length + length) % length;
     }
 
     /**