com.sun.grizzly.util.ByteBufferFactory Maven / Gradle / Ivy
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package com.sun.grizzly.util;
import java.nio.ByteBuffer;
/**
* Factory class used to create {@link ByteBuffer}.
*
* The ByteBuffer can by direct (ByteBufferType.DIRECT) or heap (ByteBufferType.HEAP)
* a view (ByteBufferType.DIRECT_VIEW) or ByteBufferType.HEAP_VIEW)
* or backed by an array (ByteBufferType.HEAP_ARRAY).
*
* @author Jean-Francois Arcand
*/
public class ByteBufferFactory{
/**
* An enumeration of all type of ByteBuffer this object can create.
*/
public enum ByteBufferType { DIRECT, HEAP, DIRECT_VIEW, HEAP_VIEW, HEAP_ARRAY }
/**
* The default capacity of the default view of a {@link ByteBuffer}
*/
public static int defaultCapacity = 8192;
/**
* The default capacity of the {@link ByteBuffer} from which views
* will be created.
*/
public static int capacity = 4000000;
/**
* The {@link ByteBuffer} used to create direct byteBuffer view.
*/
private static ByteBuffer directByteBuffer;
/**
* The {@link ByteBuffer} used to create direct byteBuffer view.
*/
private static ByteBuffer heapByteBuffer;
/**
* Private constructor.
*/
private ByteBufferFactory(){
}
/**
* Return a direct {@link ByteBuffer} view
* @param size the Size of the {@link ByteBuffer}
* @param direct - direct or non-direct buffer?
* @return {@link ByteBuffer}
*/
public synchronized static ByteBuffer allocateView(int size, boolean direct){
if (direct && (directByteBuffer == null ||
(directByteBuffer.capacity() - directByteBuffer.limit() < size))){
directByteBuffer = ByteBuffer.allocateDirect(capacity);
} else if (heapByteBuffer == null ||
(heapByteBuffer.capacity() - heapByteBuffer.limit() < size)){
heapByteBuffer = ByteBuffer.allocate(capacity);
}
ByteBuffer byteBuffer = (direct ? directByteBuffer : heapByteBuffer);
byteBuffer.limit(byteBuffer.position() + size);
ByteBuffer view = byteBuffer.slice();
byteBuffer.position(byteBuffer.limit());
return view;
}
/**
* Return a direct {@link ByteBuffer} view using the default size.
* @param direct - direct or non-direct buffer
* @return {@link ByteBuffer}
*/
public synchronized static ByteBuffer allocateView(boolean direct){
return allocateView(defaultCapacity, direct);
}
/**
* Return a new ByteBuffer based on the requested ByteBufferType
* @param type the requested ByteBufferType
* @param size the {@link ByteBuffer} size.
* @return a new ByteBuffer based on the requested ByteBufferType
*/
public static ByteBuffer allocate(ByteBufferType type,int size){
if (type == ByteBufferType.HEAP){
return ByteBuffer.allocate(size);
} else if (type == ByteBufferType.HEAP_VIEW) {
return allocateView(size,false);
} else if (type == ByteBufferType.HEAP_ARRAY) {
return ByteBuffer.wrap(new byte[size]);
} else if (type == ByteBufferType.DIRECT){
return ByteBuffer.allocateDirect(size);
} else if (type == ByteBufferType.DIRECT_VIEW){
return allocateView(size,true);
} else {
throw new IllegalStateException("Invalid ByteBuffer Type");
}
}
}