StudentHashTimer.java

package assign09;


import java.util.Random;


/**
 * This class measures the performance of bad, medium, and good student
 * Hash methods inside the HashTable class.
 * 
 * @author Paul Nuffer and Nils Streedain
 *
 */
public class StudentHashTimer {
	
	private static String allCharacters = "abcdefghijklmnopqrstuvwxyz";


	
	@SuppressWarnings("unused")
	public static void main(String[] args) {
		Random rng = new Random();
		System.out.println("N\tnanoTime");
		
		
		int incr = 10000;
		for (int probSize = 10000; probSize <= 10000; probSize += incr) {

			int timesToLoop = 1000;

			// First, spin computing stuff until one second has gone by.
			// This allows this thread to stabilize.
			long stopTime, midpointTime, startTime = System.nanoTime();
			while (System.nanoTime() - startTime < 1000000000) {
			}

			startTime = System.nanoTime();
			for (int i = 0; i < timesToLoop; i++) {	
//				HashTable<StudentBadHash, Integer> badHashCode = new HashTable<>();
//				HashTable<StudentMediumHash, Integer> mediumHashCode = new HashTable<>();
				HashTable<StudentGoodHash, Integer> goodHashCode = new HashTable<>();

				for (int j = 0; j < probSize; j++) {
					int uid = rng.nextInt(99999999);
	
					StringBuilder firstNameBuilder = new StringBuilder();
					StringBuilder lastNameBuilder = new StringBuilder();
	
					for (int k = 0; k < rng.nextInt(5); k++)
						firstNameBuilder.append(allCharacters.charAt(rng.nextInt(26)));
					for (int k = 0; k < rng.nextInt(10); k++)
						lastNameBuilder.append(allCharacters.charAt(rng.nextInt(26)));
	
					String firstName = firstNameBuilder.toString();
					String lastName = lastNameBuilder.toString();
	
//					badHashCode.put(new StudentBadHash(uid, firstName, lastName), 0);
//					mediumHashCode.put(new StudentMediumHash(uid, firstName, lastName), 0);
					goodHashCode.put(new StudentGoodHash(uid, firstName, lastName), 0);
				}
			}

			midpointTime = System.nanoTime();

			// Capture the cost of running the loop and any other operations done
			// above that are not the essential method call being timed.
			for (int i = 0; i < timesToLoop; i++) {
//				HashTable<StudentBadHash, Integer> badHashCode = new HashTable<>();
//				HashTable<StudentMediumHash, Integer> mediumHashCode = new HashTable<>();
				HashTable<StudentGoodHash, Integer> goodHashCode = new HashTable<>();

				for (int j = 0; j < probSize; j++) {
					int uid = rng.nextInt(99999999);
	
					StringBuilder firstNameBuilder = new StringBuilder();
					StringBuilder lastNameBuilder = new StringBuilder();
	
					for (int k = 0; k < rng.nextInt(5); k++)
						firstNameBuilder.append(allCharacters.charAt(rng.nextInt(26)));
					for (int k = 0; k < rng.nextInt(10); k++)
						lastNameBuilder.append(allCharacters.charAt(rng.nextInt(26)));
	
					String firstName = firstNameBuilder.toString();
					String lastName = lastNameBuilder.toString();

				}
			}

			stopTime = System.nanoTime();

			// Compute the time, subtract the cost of running the loop
			// from the cost of running the loop and searching.
			// Average it over the number of runs.
			double averageTime = ((midpointTime - startTime) - (stopTime - midpointTime)) / (double) timesToLoop;

			System.out.println(probSize + "\t" + String.format("%.5f", averageTime));
		}
	}
}