From 7590f9f8a55cfb8bed5f22aa568a351768e14fb5 Mon Sep 17 00:00:00 2001
From: Shay Banon <kimchy@gmail.com>
Date: Sun, 28 Jul 2013 22:43:35 +0200
Subject: [PATCH] move char array caching to streams

---
 .../common/io/stream/CachedStreamInput.java     |  9 ---------
 .../common/io/stream/StreamInput.java           | 17 ++++++++++++++++-
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/src/main/java/org/elasticsearch/common/io/stream/CachedStreamInput.java b/src/main/java/org/elasticsearch/common/io/stream/CachedStreamInput.java
index 894c0036251..b23cb6cde49 100644
--- a/src/main/java/org/elasticsearch/common/io/stream/CachedStreamInput.java
+++ b/src/main/java/org/elasticsearch/common/io/stream/CachedStreamInput.java
@@ -30,7 +30,6 @@ import java.lang.ref.SoftReference;
 public class CachedStreamInput {
 
     static class Entry {
-        char[] chars = new char[80];
         final HandlesStreamInput handles;
 
         Entry(HandlesStreamInput handles) {
@@ -70,12 +69,4 @@ public class CachedStreamInput {
         entry.handles.reset(compressor.streamInput(in));
         return entry.handles;
     }
-
-    public static char[] getCharArray(int size) {
-        Entry entry = instance();
-        if (entry.chars.length < size) {
-            entry.chars = new char[size];
-        }
-        return entry.chars;
-    }
 }
diff --git a/src/main/java/org/elasticsearch/common/io/stream/StreamInput.java b/src/main/java/org/elasticsearch/common/io/stream/StreamInput.java
index e2303017ca6..52bed6d85be 100644
--- a/src/main/java/org/elasticsearch/common/io/stream/StreamInput.java
+++ b/src/main/java/org/elasticsearch/common/io/stream/StreamInput.java
@@ -19,7 +19,9 @@
 
 package org.elasticsearch.common.io.stream;
 
+import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.BytesRef;
+import org.apache.lucene.util.RamUsageEstimator;
 import org.elasticsearch.Version;
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.Strings;
@@ -32,6 +34,7 @@ import org.joda.time.DateTime;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.lang.ref.SoftReference;
 import java.util.*;
 
 /**
@@ -39,6 +42,18 @@ import java.util.*;
  */
 public abstract class StreamInput extends InputStream {
 
+    private static final ThreadLocal<SoftReference<char[]>> charCache = new ThreadLocal<SoftReference<char[]>>();
+
+    private static char[] charCache(int size) {
+        SoftReference<char[]> ref = charCache.get();
+        char[] arr = (ref == null) ? null : ref.get();
+        if (arr == null || arr.length < size) {
+            arr = new char[ArrayUtil.oversize(size, RamUsageEstimator.NUM_BYTES_CHAR)];
+            charCache.set(new SoftReference<char[]>(arr));
+        }
+        return arr;
+    }
+
     private Version version = Version.CURRENT;
 
     public Version getVersion() {
@@ -255,7 +270,7 @@ public abstract class StreamInput extends InputStream {
 
     public String readString() throws IOException {
         int charCount = readVInt();
-        char[] chars = CachedStreamInput.getCharArray(charCount);
+        char[] chars = charCache(charCount);
         int c, charIndex = 0;
         while (charIndex < charCount) {
             c = readByte() & 0xff;