From c727c16707f6a7315f043fdb7800be85d527b623 Mon Sep 17 00:00:00 2001
From: Alwayswithme <phx13ye@gmail.com>
Date: Thu, 7 May 2015 10:36:49 +0800
Subject: [PATCH] ByteBufUtil use IndexOfProcessor to find occurrence.

Motivation:
The way of firstIndexOf and lastIndexOf iterating the ByteBuf is similar to forEachByte and forEachByteDesc, but have many range checks.
Modifications:
Use forEachByte and a IndexOfProcessor to find occurrence.
Result:
eliminate range checks
---
 .../java/io/netty/buffer/ByteBufUtil.java     | 29 ++++++++++---------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/buffer/src/main/java/io/netty/buffer/ByteBufUtil.java b/buffer/src/main/java/io/netty/buffer/ByteBufUtil.java
index bb05b58a4d..bf601a023b 100644
--- a/buffer/src/main/java/io/netty/buffer/ByteBufUtil.java
+++ b/buffer/src/main/java/io/netty/buffer/ByteBufUtil.java
@@ -312,13 +312,7 @@ public final class ByteBufUtil {
             return -1;
         }
 
-        for (int i = fromIndex; i < toIndex; i ++) {
-            if (buffer.getByte(i) == value) {
-                return i;
-            }
-        }
-
-        return -1;
+        return buffer.forEachByte(fromIndex, toIndex - fromIndex, new IndexOfProcessor(value));
     }
 
     private static int lastIndexOf(ByteBuf buffer, int fromIndex, int toIndex, byte value) {
@@ -327,13 +321,7 @@ public final class ByteBufUtil {
             return -1;
         }
 
-        for (int i = fromIndex - 1; i >= toIndex; i --) {
-            if (buffer.getByte(i) == value) {
-                return i;
-            }
-        }
-
-        return -1;
+        return buffer.forEachByteDesc(toIndex, fromIndex - toIndex, new IndexOfProcessor(value));
     }
 
     /**
@@ -566,5 +554,18 @@ public final class ByteBufUtil {
         }
     }
 
+    private static class IndexOfProcessor implements ByteBufProcessor {
+        private final byte byteToFind;
+
+        public IndexOfProcessor(byte byteToFind) {
+            this.byteToFind = byteToFind;
+        }
+
+        @Override
+        public boolean process(byte value) {
+            return value != byteToFind;
+        }
+    }
+
     private ByteBufUtil() { }
 }