linkable.java

peersim最新版1.0.4

/*
 * Copyright (c) 2003-2005 The BISON Project
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */
		
package peersim.core;


/**
* Instances of classes implementing this interface can form networks (graphs)
* in the simulator framework.
* The interface is similar to one of a container (containing neighbors),
* only the types of the contained elements have to be {@link Node}.
* The neighbor collection is defined in a random access list style, but
* it must follow the contract of a set too (elements must be unique).
* <p>
* Also note that there is no possibility to remove elements from the
* neighbor set. This is because removal is usually costly and it does not make
* sense in the context of our applications,
* where this interface is used for 1) initialization and 2)
* providing an interface for other protocols for accessing the neighbor list.
* Protocols that manage links remove, refresh, etc their link set internally
* or through custom methods.
* Therefore it would only put an unnecessary burden on implementors.
*/
public interface Linkable extends Cleanable {
 

	/**
	* Returns the size of the neighbor list.
	*/
	public int degree();

	/**
	* Returns the neighbor with the given index. The contract is that
	* listing the elements from index 0 to index degree()-1 should list
	* each element exactly once if this object is not modified in the
	* meantime. It throws an IndexOutOfBounds exception if i is negative
	* or larger than or equal to {@link #degree}.
	*/
	public Node getNeighbor(int i);

	/**
	* Add a neighbor to the current set of neighbors. If neighbor
	* is not yet a neighbor but it cannot be added from other reasons,
	* this method should not return normally, that is, it must throw
	* a runtime exception.
	* @return true if the neighbor has been inserted; false if the 
	*    node is already a neighbor of this node
	*/
	public boolean addNeighbor(Node neighbour);

	/**
	* Returns true if the given node is a member of the neighbor set.
	*/
	public boolean contains(Node neighbor);
	
	/**
	* A possibility for optimization. An implementation should try to
	* compress its internal representation. Normally this is called
	* by initializers or other components when
	* no increase in the expected size of the neighborhood can be
	* expected.
	*/
	public void pack();
}