init

src/org/fog/application/selectivity/BurstySelectivity.java

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+package org.fog.application.selectivity;
+
+import org.cloudbus.cloudsim.core.CloudSim;
+
+/**
+ * Generates an output tuple for every input tuple according to a bursty model.
+ * During high burst period, all input tuples result in an output tuple.
+ * During low burst period, no input tuples result in an output tuple.
+ * @author Harshit Gupta
+ *
+ */
+public class BurstySelectivity implements SelectivityModel{
+
+	/**
+	 * Duration of the low burst period
+	 */
+	double burstLowPeriod;
+	
+	/**
+	 * Duration of the high burst period
+	 */
+	double burstHighPeriod;
+	
+	/**
+	 * First instance of the start of high burst period, using which subsequent burst periods will be calculated.
+	 */
+	double firstHighTime;
+	
+	public BurstySelectivity(double burstLowPeriod, double burstHighPeriod, double firstHighTime){
+		setBurstLowPeriod(burstLowPeriod);
+		setBurstHighPeriod(burstHighPeriod);
+		setFirstHighTime(firstHighTime);
+	}
+	
+	/**
+	 * If the current time falls in the high burst period of the specified burst model, an output tuple is generated for the incoming tuple.
+	 */
+	@Override
+	public boolean canSelect() {
+		double time = CloudSim.clock() + getFirstHighTime();
+		double burstPeriod = getBurstHighPeriod()+getBurstLowPeriod();
+		double burstStartTime = burstPeriod*((int)(time/burstPeriod));
+		if(time <= burstStartTime + getBurstHighPeriod())
+			return true;
+		else
+			return false;
+	}
+
+	/**
+	 * The mean tuple generation rate is the fraction of high burst period in the total burst period.
+	 */
+	@Override
+	public double getMeanRate() {
+		return getBurstHighPeriod()/(getBurstHighPeriod()+getBurstLowPeriod());
+	}
+
+	/**
+	 * Maximum tuple generation rate equals 1 (when the burst is high)
+	 */
+	@Override
+	public double getMaxRate() {
+		return 1;
+	}
+
+	public double getBurstLowPeriod() {
+		return burstLowPeriod;
+	}
+
+	public void setBurstLowPeriod(double burstLowPeriod) {
+		this.burstLowPeriod = burstLowPeriod;
+	}
+
+	public double getBurstHighPeriod() {
+		return burstHighPeriod;
+	}
+
+	public void setBurstHighPeriod(double burstHighPeriod) {
+		this.burstHighPeriod = burstHighPeriod;
+	}
+
+	public double getFirstHighTime() {
+		return firstHighTime;
+	}
+
+	public void setFirstHighTime(double firstHighTime) {
+		this.firstHighTime = firstHighTime;
+	}
+
+}

src/org/fog/application/selectivity/FractionalSelectivity.java

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+package org.fog.application.selectivity;
+
+/**
+ * Generates an output tuple for an incoming input tuple with a fixed probability
+ * @author Harshit Gupta
+ *
+ */
+public class FractionalSelectivity implements SelectivityModel{
+
+	/**
+	 * The fixed probability of output tuple creation per incoming input tuple
+	 */
+	double selectivity;
+	
+	public FractionalSelectivity(double selectivity){
+		setSelectivity(selectivity);
+	}
+	public double getSelectivity() {
+		return selectivity;
+	}
+	public void setSelectivity(double selectivity) {
+		this.selectivity = selectivity;
+	}
+	
+	@Override
+	public boolean canSelect() {
+		if(Math.random() < getSelectivity()) // if the probability condition is satisfied
+			return true;
+		return false;
+	}
+	
+	@Override
+	public double getMeanRate() {
+		return getSelectivity(); // the average rate of tuple generation is the fixed probability value
+	}
+	
+	@Override
+	public double getMaxRate() {
+		return getSelectivity(); // the maximum rate of tuple generation is the fixed probability value
+	}
+	
+}

src/org/fog/application/selectivity/SelectivityModel.java

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+package org.fog.application.selectivity;
+
+/**
+ * Class representing the input-output relationships of application modules.
+ * @author Harshit Gupta
+ *
+ */
+public interface SelectivityModel {
+
+	/**
+	 * Function called to check whether incoming tuple can generate an output tuple.
+	 * @return true if a tuple can be emitted (selection possible)
+	 */
+	public boolean canSelect();
+	
+	/**
+	 * Average number of tuples generated per incoming input tuple.
+	 * @return avg tuple generation rate
+	 */
+	public double getMeanRate();
+	
+	/**
+	 * Maximum number of tuples generated per incoming input tuple.
+	 * @return max tuple generation rate
+	 */
+	public double getMaxRate();
+	
+}