+++ /dev/null
-/*
- * 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.dynamics;
-
-import peersim.config.Configuration;
-import peersim.core.*;
-
-/**
- * Makes the network size oscillate.
- * The network size will be the function of time, parameterized by this
- * parameter. The size function is
- * <code>avg+sin(time*pi/{@value #PAR_PERIOD})*ampl</code> where
- * <code>avg=({@value #PAR_MAX}+{@value #PAR_MIN})/2</code> and
- * <code>ampl=({@value #PAR_MAX}-{@value #PAR_MIN})/2</code>.
- * This function is independent of how many times this class is executed, that
- * is, whenever it is executed, it takes the current time and sets the network
- * size accordingly.
- */
-public class OscillatingNetwork implements Control
-{
-
-//--------------------------------------------------------------------------
-//Parameters
-//--------------------------------------------------------------------------
-
-/**
- * Config parameter which gives the prefix of node initializers. An arbitrary
- * number of node initializers can be specified (Along with their parameters).
- * These will be applied
- * on the newly created nodes. The initializers are ordered according to
- * alphabetical order if their ID.
- * Example:
- * <pre>
-control.0 DynamicNetwork
-control.0.init.0 RandNI
-control.0.init.0.k 5
-control.0.init.0.protocol somelinkable
-...
- * </pre>
- * @config
- */
-private static final String PAR_INIT = "init";
-
-/**
- * Nodes are added until the size specified by this parameter is reached. The
- * network will never exceed this size as a result of this class.
- * If not set, there will be no limit on the size of the network.
- * @config
- */
-private static final String PAR_MAX = "maxsize";
-
-/**
- * Nodes are removed until the size specified by this parameter is reached. The
- * network will never go below this size as a result of this class.
- * Defaults to 0.
- * @config
- */
-private static final String PAR_MIN = "minsize";
-
-/**
- * Config parameter used to define the length of one period of the oscillation.
- * The network size will be the function of time, parameterized by this
- * parameter. The size function is
- * <code>avg+sin(time*pi/{@value #PAR_PERIOD})*ampl</code> where
- * <code>avg=({@value #PAR_MAX}+{@value #PAR_MIN})/2</code> and
- * <code>ampl=({@value #PAR_MAX}-{@value #PAR_MIN})/2</code>.
- * @config
- */
-private static final String PAR_PERIOD = "period";
-
-
-//--------------------------------------------------------------------------
-//Fields
-//--------------------------------------------------------------------------
-
-/** Period */
-private final int period;
-
-/** Maximum size */
-private final int minsize;
-
-/** Minimum size */
-private final int maxsize;
-
-/** New nodes initializers */
-private final NodeInitializer[] inits;
-
-
-//--------------------------------------------------------------------------
-// Initialization
-//--------------------------------------------------------------------------
-
-/**
- * Standard constructor that reads the configuration parameters. Invoked by the
- * simulation engine.
- * @param prefix
- * the configuration prefix for this class
- */
-public OscillatingNetwork(String prefix)
-{
-
- period = Configuration.getInt(prefix + "." + PAR_PERIOD);
- maxsize =
- Configuration.getInt(
- prefix + "." + PAR_MAX,
- Integer.MAX_VALUE);
- minsize = Configuration.getInt(prefix + "." + PAR_MIN, 0);
-
- Object[] tmp = Configuration.getInstanceArray(prefix + "." + PAR_INIT);
- inits = new NodeInitializer[tmp.length];
- for (int i = 0; i < tmp.length; ++i)
- {
- inits[i] = (NodeInitializer) tmp[i];
- }
-}
-
-//--------------------------------------------------------------------------
-// Methods
-//--------------------------------------------------------------------------
-
-/**
- * Adds n nodes to the network. Extending classes can implement any algorithm to
- * do that. The default algorithm adds the given number of nodes after calling
- * all the configured initializers on them.
- *
- * @param n
- * the number of nodes to add, must be non-negative.
- */
-protected void add(int n)
-{
- for (int i = 0; i < n; ++i) {
- Node newnode = (Node) Network.prototype.clone();
- for (int j = 0; j < inits.length; ++j) {
- inits[j].initialize(newnode);
- }
- Network.add(newnode);
- }
-}
-
-// ------------------------------------------------------------------
-
-/**
- * Removes n nodes from the network. Extending classes can implement any
- * algorithm to do that. The default algorithm removes <em>random</em>
- * nodes <em>permanently</em> simply by calling {@link Network#remove(int)}.
- * @param n the number of nodes to remove
- */
-protected void remove(int n)
-{
- for (int i = 0; i < n; ++i) {
- Network.remove(CommonState.r.nextInt(Network.size()));
- }
-}
-
-// ------------------------------------------------------------------
-
-/**
- * Takes the current time and sets the network size according to a periodic
- * function of time.
- * The size function is
- * <code>avg+sin(time*pi/{@value #PAR_PERIOD})*ampl</code> where
- * <code>avg=({@value #PAR_MAX}+{@value #PAR_MIN})/2</code> and
- * <code>ampl=({@value #PAR_MAX}-{@value #PAR_MIN})/2</code>.
- * Calls {@link #add(int)} or {@link #remove} depending on whether the size
- * needs to be increased or decreased to get the desired size.
- * @return always false
- */
-public boolean execute()
-{
- long time = CommonState.getTime();
- int amplitude = (maxsize - minsize) / 2;
- int newsize = (maxsize + minsize) / 2 +
- (int) (Math.sin(((double) time) / period * Math.PI) *
- amplitude);
- int diff = newsize - Network.size();
- if (diff < 0)
- remove(-diff);
- else
- add(diff);
-
- return false;
-}
-
-}
