Make SslBufferPool an interface

This commit is contained in:
Jeff Pinner 2012-05-18 13:44:23 -07:00
parent 3d49975a3c
commit ddb7d75c96
3 changed files with 103 additions and 97 deletions

View File

@ -0,0 +1,93 @@
/*
* Copyright 2011 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
package io.netty.handler.ssl;
import java.nio.ByteBuffer;
import javax.net.ssl.SSLEngine;
public class DefaultSslBufferPool implements SslBufferPool {
private static final int DEFAULT_POOL_SIZE = MAX_PACKET_SIZE * 1024;
private final ByteBuffer[] pool;
private final int maxBufferCount;
private int index;
/**
* Creates a new buffer pool whose size is {@code 18113536}, which can
* hold {@code 1024} buffers.
*/
public DefaultSslBufferPool() {
this(DEFAULT_POOL_SIZE);
}
/**
* Creates a new buffer pool.
*
* @param maxPoolSize the maximum number of bytes that this pool can hold
*/
public DefaultSslBufferPool(int maxPoolSize) {
if (maxPoolSize <= 0) {
throw new IllegalArgumentException("maxPoolSize: " + maxPoolSize);
}
int maxBufferCount = maxPoolSize / MAX_PACKET_SIZE;
if (maxPoolSize % MAX_PACKET_SIZE != 0) {
maxBufferCount ++;
}
pool = new ByteBuffer[maxBufferCount];
this.maxBufferCount = maxBufferCount;
}
/**
* Returns the maximum size of this pool in byte unit. The returned value
* can be somewhat different from what was specified in the constructor.
*/
public int getMaxPoolSize() {
return maxBufferCount * MAX_PACKET_SIZE;
}
/**
* Returns the number of bytes which were allocated but have not been
* acquired yet. You can estimate how optimal the specified maximum pool
* size is from this value. If it keeps returning {@code 0}, it means the
* pool is getting exhausted. If it keeps returns a unnecessarily big
* value, it means the pool is wasting the heap space.
*/
public synchronized int getUnacquiredPoolSize() {
return index * MAX_PACKET_SIZE;
}
public ByteBuffer acquireBuffer() {
synchronized {
if (index == 0) {
return ByteBuffer.allocate(MAX_PACKET_SIZE);
} else {
return (ByteBuffer) pool[-- index].clear();
}
}
}
public void releaseBuffer(ByteBuffer buffer) {
synchronized {
if (index < maxBufferCount) {
pool[index ++] = buffer;
}
}
}
}

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@ -17,15 +17,10 @@ package io.netty.handler.ssl;
import java.nio.ByteBuffer;
import javax.net.ssl.SSLEngine;
/**
* A {@link ByteBuffer} pool dedicated for {@link SslHandler} performance
* improvement.
* <p>
* In most cases, you won't need to create a new pool instance because
* {@link SslHandler} has a default pool instance internally.
* <p>
*
* The reason why {@link SslHandler} requires a buffer pool is because the
* current {@link SSLEngine} implementation always requires a 17KiB buffer for
* every 'wrap' and 'unwrap' operation. In most cases, the actual size of the
@ -33,103 +28,21 @@ import javax.net.ssl.SSLEngine;
* buffer for every 'wrap' and 'unwrap' operation wastes a lot of memory
* bandwidth, resulting in the application performance degradation.
*/
public class SslBufferPool {
public interface SslBufferPool {
// Add 1024 as a room for compressed data and another 1024 for Apache Harmony compatibility.
private static final int MAX_PACKET_SIZE = 16665 + 2048;
private static final int DEFAULT_POOL_SIZE = MAX_PACKET_SIZE * 1024;
private final ByteBuffer[] pool;
private final int maxBufferCount;
private int index;
/**
* Creates a new buffer pool whose size is {@code 18113536}, which can
* hold {@code 1024} buffers.
*/
public SslBufferPool() {
this(DEFAULT_POOL_SIZE);
}
/**
* Creates a new buffer pool.
*
* @param maxPoolSize the maximum number of bytes that this pool can hold
*/
public SslBufferPool(int maxPoolSize) {
if (maxPoolSize <= 0) {
throw new IllegalArgumentException("maxPoolSize: " + maxPoolSize);
}
int maxBufferCount = maxPoolSize / MAX_PACKET_SIZE;
if (maxPoolSize % MAX_PACKET_SIZE != 0) {
maxBufferCount ++;
}
pool = new ByteBuffer[maxBufferCount];
this.maxBufferCount = maxBufferCount;
}
/**
* Returns the maximum size of this pool in byte unit. The returned value
* can be somewhat different from what was specified in the constructor.
*/
public int getMaxPoolSize() {
return maxBufferCount * MAX_PACKET_SIZE;
}
/**
* Returns the number of bytes which were allocated but have not been
* acquired yet. You can estimate how optimal the specified maximum pool
* size is from this value. If it keeps returning {@code 0}, it means the
* pool is getting exhausted. If it keeps returns a unnecessarily big
* value, it means the pool is wasting the heap space.
*/
public synchronized int getUnacquiredPoolSize() {
return index * MAX_PACKET_SIZE;
}
// Returned buffers must be large enough to accomodate the maximum SSL record size.
// Header (5) + Data (2^14) + Compression (1024) + Encryption (1024) + MAC (20) + Padding (256)
int MAX_PACKET_SIZE = 18713;
/**
* Acquire a new {@link ByteBuffer} out of the {@link SslBufferPool}
*
*/
public ByteBuffer acquireBuffer() {
return acquire();
}
ByteBuffer acquireBuffer();
/**
* Will get removed. Please use {@link #acquireBuffer()}
*
*/
@Deprecated
synchronized ByteBuffer acquire() {
if (index == 0) {
return ByteBuffer.allocate(MAX_PACKET_SIZE);
} else {
return (ByteBuffer) pool[-- index].clear();
}
}
/**
* Release a previous acquired {@link ByteBuffer}
* Release a previously acquired {@link ByteBuffer}
*
* @param buffer
*/
public void releaseBuffer(ByteBuffer buffer) {
release(buffer);
}
/**
* Will get removed. Please use {@link #releaseBuffer(ByteBuffer)}
*
* @deprecated
*
*/
@Deprecated
synchronized void release(ByteBuffer buffer) {
if (index < maxBufferCount) {
pool[index ++] = buffer;
}
}
void releaseBuffer(ByteBuffer buffer);
}

View File

@ -170,7 +170,7 @@ public class SslHandler extends FrameDecoder
*/
public static synchronized SslBufferPool getDefaultBufferPool() {
if (defaultBufferPool == null) {
defaultBufferPool = new SslBufferPool();
defaultBufferPool = new DefaultSslBufferPool();
}
return defaultBufferPool;
}