From 70820d7be6f47a57fb1b3dfbf39b1fa574137a06 Mon Sep 17 00:00:00 2001
From: zzz <zzz@mail.i2p>
Date: Sat, 25 Aug 2012 14:44:52 +0000
Subject: [PATCH] * SDSCache: Reduce min and increase max size *
SimpleByteCache: Change from LBQ to ABQ to reduce object churn
---
core/java/src/net/i2p/data/SDSCache.java | 4 ++--
.../src/net/i2p/util/SimpleByteCache.java | 20 ++++++++++++++++---
2 files changed, 19 insertions(+), 5 deletions(-)
diff --git a/core/java/src/net/i2p/data/SDSCache.java b/core/java/src/net/i2p/data/SDSCache.java
index 11b730664a..474e964791 100644
--- a/core/java/src/net/i2p/data/SDSCache.java
+++ b/core/java/src/net/i2p/data/SDSCache.java
@@ -45,8 +45,8 @@ public class SDSCache<V extends SimpleDataStructure> {
//private static final Log _log = I2PAppContext.getGlobalContext().logManager().getLog(SDSCache.class);
private static final Class[] conArg = new Class[] { byte[].class };
- private static final double MIN_FACTOR = 0.25;
- private static final double MAX_FACTOR = 3.0;
+ private static final double MIN_FACTOR = 0.20;
+ private static final double MAX_FACTOR = 5.0;
private static final double FACTOR;
static {
long maxMemory = Runtime.getRuntime().maxMemory();
diff --git a/core/java/src/net/i2p/util/SimpleByteCache.java b/core/java/src/net/i2p/util/SimpleByteCache.java
index 4aae936504..01d116abea 100644
--- a/core/java/src/net/i2p/util/SimpleByteCache.java
+++ b/core/java/src/net/i2p/util/SimpleByteCache.java
@@ -2,6 +2,7 @@ package net.i2p.util;
import java.util.Map;
import java.util.Queue;
+import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.LinkedBlockingQueue;
@@ -19,6 +20,9 @@ public final class SimpleByteCache {
private static final int DEFAULT_SIZE = 16;
+ /** up to this, use ABQ to minimize object churn and for performance; above this, use LBQ for two locks */
+ private static final int MAX_FOR_ABQ = 64;
+
/**
* Get a cache responsible for arrays of the given size
*
@@ -58,11 +62,11 @@ public final class SimpleByteCache {
/** list of available and available entries */
private Queue<byte[]> _available;
private int _maxCached;
- private int _entrySize;
+ private final int _entrySize;
private SimpleByteCache(int maxCachedEntries, int entrySize) {
- _available = new LinkedBlockingQueue(maxCachedEntries);
_maxCached = maxCachedEntries;
+ _available = createQueue();
_entrySize = entrySize;
}
@@ -70,13 +74,23 @@ public final class SimpleByteCache {
if (_maxCached >= maxCachedEntries) return;
_maxCached = maxCachedEntries;
// make a bigger one, move the cached items over
- Queue<byte[]> newLBQ = new LinkedBlockingQueue(maxCachedEntries);
+ Queue<byte[]> newLBQ = createQueue();
byte[] ba;
while ((ba = _available.poll()) != null)
newLBQ.offer(ba);
_available = newLBQ;
}
+ /**
+ * @return LBQ or ABQ
+ * @since 0.9.2
+ */
+ private Queue<byte[]> createQueue() {
+ if (_maxCached <= MAX_FOR_ABQ)
+ return new ArrayBlockingQueue(_maxCached);
+ return new LinkedBlockingQueue(_maxCached);
+ }
+
/**
* Get the next available array, either from the cache or a brand new one
*/
--
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