From 9b27b8a7580946e98eb590280ce132199553c14d Mon Sep 17 00:00:00 2001
From: leventov <leventov@ya.ru>
Date: Tue, 7 Oct 2014 00:56:03 +0400
Subject: [PATCH] Memoize hash computation in CopyingMetaBytesInterop

---
 .../map/serialization/CopyingMetaBytesInterop.java         | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/main/java/net/openhft/chronicle/map/serialization/CopyingMetaBytesInterop.java b/src/main/java/net/openhft/chronicle/map/serialization/CopyingMetaBytesInterop.java
index 1c1922a8f..a8fc3d368 100644
--- a/src/main/java/net/openhft/chronicle/map/serialization/CopyingMetaBytesInterop.java
+++ b/src/main/java/net/openhft/chronicle/map/serialization/CopyingMetaBytesInterop.java
@@ -34,6 +34,7 @@ public abstract class CopyingMetaBytesInterop<E, W> implements MetaBytesInterop<
 
     final DirectBytesBuffer buffer;
     transient long size;
+    transient long hash;
     transient W writer;
     transient E cur;
 
@@ -49,6 +50,7 @@ public abstract class CopyingMetaBytesInterop<E, W> implements MetaBytesInterop<
             innerWrite(writer, buffer, e);
             buffer.flip();
             size = buffer.remaining();
+            hash = 0L;
         }
     }
 
@@ -66,7 +68,10 @@ public abstract class CopyingMetaBytesInterop<E, W> implements MetaBytesInterop<
 
     @Override
     public long hash(W writer, E e) {
-        return Hasher.hash(buffer.buffer);
+        long h;
+        if ((h = hash) == 0L)
+            return hash = Hasher.hash(buffer.buffer);
+        return h;
     }
 
     @Override