Refatoring

- separated net topology from the simulation nodes
- moved files in a better hierarchy

src/main/java/net/berack/upo/valpre/sim/ServerNode.java

@@ -0,0 +1,96 @@
+package net.berack.upo.valpre.sim;
+
+import net.berack.upo.valpre.rand.Distribution;
+import net.berack.upo.valpre.rand.Rng;
+
+/**
+ * Represents a node in the network. It can be a source, a queue, or a sink
+ * based on the configuration passed as parameters.
+ */
+public class ServerNode {
+    public final String name;
+    public final int maxServers;
+    public final int spawnArrivals;
+    public final Distribution distribution;
+
+    /**
+     * Creates a source node with the given name and distribution.
+     * It swpawns infinite arrivals (Integer.MAX_VALUE) that are served by infinite
+     * servers (Integer.MAX_VALUE).
+     * 
+     * @param name         The name of the node.
+     * @param distribution The distribution of the inter-arrival times.
+     * @return The created source node.
+     */
+    public static ServerNode createSource(String name, Distribution distribution) {
+        return new ServerNode(name, Integer.MAX_VALUE, distribution, Integer.MAX_VALUE);
+    }
+
+    /**
+     * Creates a source node with the given name, distribution, and number of
+     * arrivals to spawn that are served by infinite servers (Integer.MAX_VALUE).
+     * 
+     * @param name          The name of the node.
+     * @param distribution  The distribution of the inter-arrival times.
+     * @param spawnArrivals The number of arrivals to spawn.
+     * @return The created source node.
+     */
+    public static ServerNode createLimitedSource(String name, Distribution distribution, int spawnArrivals) {
+        return new ServerNode(name, Integer.MAX_VALUE, distribution, spawnArrivals);
+    }
+
+    /**
+     * Creates a queue node with the given name, maximum number of servers, and
+     * distribution.
+     * 
+     * @param name         The name of the node.
+     * @param maxServers   The maximum number of servers in the queue.
+     * @param distribution The distribution of the service times.
+     * @return The created queue node.
+     */
+    public static ServerNode createQueue(String name, int maxServers, Distribution distribution) {
+        return new ServerNode(name, maxServers, distribution, 0);
+    }
+
+    /**
+     * Creates a generic node with the given name and distribution.
+     * 
+     * @param name           The name of the node.
+     * @param maxServers     The maximum number of servers in the queue.
+     * @param distribution   The distribution of the service times.
+     * @param spawnArrivals  The number of arrivals to spawn.
+     */
+    public ServerNode(String name, int maxServers, Distribution distribution, int spawnArrivals) {
+        this.name = name;
+        this.maxServers = maxServers;
+        this.distribution = distribution;
+        this.spawnArrivals = spawnArrivals;
+    }
+
+    /**
+     * Gets a positive sample from the distribution.
+     * This is useful if you need to generate a positive value from a distribution
+     * that can generate negative values. For example, the normal distribution.
+     * 
+     * @param rng The random number generator to use.
+     * @return A positive sample from the distribution.
+     */
+    public double getPositiveSample(Rng rng) {
+        double sample;
+        do {
+            sample = this.distribution.sample(rng);
+        } while (sample < 0);
+        return sample;
+    }
+
+    /**
+     * Determines if the node should spawn an arrival based on the number of
+     * arrivals.
+     * 
+     * @param numArrivals The number of arrivals to check against.
+     * @return True if the node should spawn an arrival, false otherwise.
+     */
+    public boolean shouldSpawnArrival(double numArrivals) {
+        return this.spawnArrivals > numArrivals;
+    }
+}