--- /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.transport;
+
+import peersim.config.*;
+import peersim.core.*;
+import peersim.edsim.*;
+
+
+/**
+ * Implement a transport layer that reliably delivers messages with a random
+ * delay, that is drawn from the configured interval according to the uniform
+ * distribution.
+ *
+ * @author Alberto Montresor
+ * @version $Revision: 1.14 $
+ */
+public final class UniformRandomTransport implements Transport
+{
+
+//---------------------------------------------------------------------
+//Parameters
+//---------------------------------------------------------------------
+
+/**
+ * String name of the parameter used to configure the minimum latency.
+ * @config
+ */
+private static final String PAR_MINDELAY = "mindelay";
+
+/**
+ * String name of the parameter used to configure the maximum latency.
+ * Defaults to {@value #PAR_MINDELAY}, which results in a constant delay.
+ * @config
+ */
+private static final String PAR_MAXDELAY = "maxdelay";
+
+//---------------------------------------------------------------------
+//Fields
+//---------------------------------------------------------------------
+
+/** Minimum delay for message sending */
+private final long min;
+
+/** Difference between the max and min delay plus one. That is, max delay is
+* min+range-1.
+*/
+private final long range;
+
+
+//---------------------------------------------------------------------
+//Initialization
+//---------------------------------------------------------------------
+
+/**
+ * Reads configuration parameter.
+ */
+public UniformRandomTransport(String prefix)
+{
+ min = Configuration.getLong(prefix + "." + PAR_MINDELAY);
+ long max = Configuration.getLong(prefix + "." + PAR_MAXDELAY,min);
+ if (max < min)
+ throw new IllegalParameterException(prefix+"."+PAR_MAXDELAY,
+ "The maximum latency cannot be smaller than the minimum latency");
+ range = max-min+1;
+}
+
+//---------------------------------------------------------------------
+
+/**
+* Returns <code>this</code>. This way only one instance exists in the system
+* that is linked from all the nodes. This is because this protocol has no
+* node specific state.
+*/
+public Object clone()
+{
+ return this;
+}
+
+//---------------------------------------------------------------------
+//Methods
+//---------------------------------------------------------------------
+
+/**
+ * Delivers the message with a random
+ * delay, that is drawn from the configured interval according to the uniform
+ * distribution.
+*/
+public void send(Node src, Node dest, Object msg, int pid)
+{
+ // avoid calling nextLong if possible
+ long delay = (range==1?min:min + CommonState.r.nextLong(range));
+ EDSimulator.add(delay, msg, dest, pid);
+}
+
+/**
+ * Returns a random
+ * delay, that is drawn from the configured interval according to the uniform
+ * distribution.
+*/
+public long getLatency(Node src, Node dest)
+{
+ return (range==1?min:min + CommonState.r.nextLong(range));
+}
+
+
+}
