Initial commit from SVN.

Orb/src/com/de22/orb/BufferRepository.java

@@ -0,0 +1,111 @@
+/*
+ * Copyright (c) 2008 Declarative Engineering LLC.
+ * All rights reserved.  This program and the accompanying materials
+ * are made available under the terms of the Declarative Engineering LLC
+ * verson 1 which accompanies this distribution, and is available at
+ * http://declarativeengineering.com/legal/DE_Developer_License_v1.txt
+ */
+package com.de22.orb;
+
+import java.nio.ByteBuffer;
+
+import com.common.util.IList;
+import com.common.util.LiteList;
+import com.common.util.optimized.IntObjectHashMap;
+
+/**
+ * This class provides the orb an opportunity to reduce GC by reusing a majority of the buffers, but also increases overhead due to additional synchronization.
+ * The caller must synchronize on the repository prior to checking out or checking in any buffers.
+ */
+public class BufferRepository {
+	/** The maximum number of buffers that will be cached. */
+	private final static int maximumCachedBuffers = 100;
+	/** The size of the message buffers.  All cached message buffers will be of the same size. */
+	private final static int messageBufferSize = 100000;  //Note: This must be larger than the encryption buffer sizes.//
+	/** The only instance of this class. */
+	private final static BufferRepository singleton = new BufferRepository();
+	
+	/** The collection of currently cached message buffers. */
+	private LiteList cachedMessageBuffers = new LiteList(maximumCachedBuffers);
+	/** The collection of collections of cached byte buffers.  The byte buffer lists are mapped by their size. */
+	private IntObjectHashMap cachedByteBuffers = new IntObjectHashMap(20);
+/**
+ * Gets the one and only instance of this class.
+ * @return The only instance of this class.
+ */
+public static BufferRepository getSingleton() {
+	return singleton;
+}//getSingleton()//
+/**
+ * BufferRepository constructor.
+ */
+private BufferRepository() {
+}//BufferRepository()//
+/**
+ * Gets the size of the message buffers.
+ * <p>Note: The caller does not need to synchronize on this since it must either be final, or set before the orb is started and never changed.</p>
+ * @return The message buffer size.
+ */
+public int getMessageBufferSize() {
+	return messageBufferSize;
+}//getMessageBufferSize()//
+/**
+ * Checks out a message buffer.
+ * @return The buffer checked out, never null.
+ */
+public byte[] checkOutMessageBuffer() {
+	byte[] result;
+	
+	if(cachedMessageBuffers.getSize() > 0) {
+		result = (byte[]) cachedMessageBuffers.remove(cachedMessageBuffers.getSize() - 1);
+	}//if//
+	else {
+		result = new byte[messageBufferSize];
+	}//else//
+	
+	return result;
+}//checkOutMessageBuffer()//
+/**
+ * Checks in a previously checked out message buffer.
+ * @param buffer The buffer being checked in for reuse.
+ */
+public void checkInMessageBuffer(byte[] buffer) {
+	if(buffer.length == messageBufferSize && cachedMessageBuffers.getSize() < maximumCachedBuffers) {
+		cachedMessageBuffers.add(buffer);
+	}//if//
+}//checkInMessageBuffer()//
+/**
+ * Checks out a byte buffer.
+ * @param size The size of the required byte buffer.
+ * @return The buffer checked out, never null.
+ */
+public ByteBuffer checkOutByteBuffer(int size) {
+	IList buffers = (IList) cachedByteBuffers.get(size);
+	ByteBuffer result;
+	
+	if(buffers != null && buffers.getSize() > 0) {
+		result = (ByteBuffer) buffers.remove(buffers.getSize() - 1);
+	}//if//
+	else {
+		result = ByteBuffer.allocate(size);
+	}//else//
+	
+	return result;
+}//checkOutByteBuffer()//
+/**
+ * Checks in a previously checked out byte buffer.
+ * @param buffer The buffer being checked in for reuse.
+ */
+public void checkInByteBuffer(ByteBuffer buffer) {
+	IList buffers = (IList) cachedByteBuffers.get(buffer.capacity());
+	
+	if(buffers == null) {
+		buffers = new LiteList(maximumCachedBuffers);
+		buffers.add(buffer);
+		cachedByteBuffers.put(buffer.capacity(), buffers);
+	}//if//
+	else if(buffers.getSize() < maximumCachedBuffers) {
+		buffers.add(buffer);
+	}//else if//
+}//checkInByteBuffer()//
+}//BufferRepository//