Remove Optionals and refactor

1 files changed, 35 insertions, 16 deletions

diff --git a/AlgoAufgabe1/src/de/ostfalia/algo/ws18/s1/Management.java b/AlgoAufgabe1/src/de/ostfalia/algo/ws18/s1/Management.java
index 2be04c7..59c5d20 100644
--- a/AlgoAufgabe1/src/de/ostfalia/algo/ws18/s1/Management.java
+++ b/AlgoAufgabe1/src/de/ostfalia/algo/ws18/s1/Management.java
@@ -4,7 +4,6 @@ import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileReader;
 import java.io.IOException;
-import java.util.Optional;
 import java.util.function.Predicate;
 
 import de.ostfalia.algo.ws18.base.IManagement;
@@ -13,14 +12,18 @@ import de.ostfalia.algo.ws18.base.KindOfSport;
 
 public class Management implements IManagement {
 	/**
-	 * Tracks the number of operations.
+	 * Track the number of operations.
 	 */
 	private int numberOfOperations = 0;
+	/**
+	 * Track the execution time.
+	 */
+	private long lastCheckpointNs;
 	
 	/**
 	 * Current head node.
 	 */
-	private Optional<LinkedListNode<IMember>> head = Optional.empty();
+	private LinkedListNode<IMember> head;
 	/**
 	 * Length of the list.
 	 */
@@ -61,7 +64,7 @@ public class Management implements IManagement {
 	 * 
 	 * @param filename Path to the CSV file.
 	 */
-	private void importFromFile(String filename) {
+	public void importFromFile(String filename) {
 		File file = new File(filename);
 
 		try (BufferedReader bufferedReader = new BufferedReader(new FileReader(file))) {
@@ -80,14 +83,14 @@ public class Management implements IManagement {
 	 */
 	private Management filter(Predicate<IMember> criteria, boolean breakAfterFirstMatch) {
 		Management result = new Management();
-		if (!this.head.isPresent()) {
+		if (this.size == 0) {
 			return result;
 		}
 
 		// searches from head, inserts at head -> result is reversed
 		result.reverse();
 		
-		LinkedListNode<IMember> currentNode = this.head.get();
+		LinkedListNode<IMember> currentNode = this.head;
 		do {
 			// traverse = 1 operation
 			this.numberOfOperations++;
@@ -108,10 +111,15 @@ public class Management implements IManagement {
 	 * Find the first element that matches the given criteria.
 	 * 
 	 * @param criteria Criteria to search for.
-	 * @return An optional containing the first element that matches the given criteria.
+	 * @return The first element that matches the given criteria or null.
 	 */
-	private Optional<IMember> search(Predicate<IMember> criteria) {
-		return this.filter(criteria, true).head.map(head -> head.getValue());
+	private IMember search(Predicate<IMember> criteria) {
+		Management filteredList = this.filter(criteria, true);
+		if (filteredList.size() == 0) {
+			return null;
+		} else {
+			return filteredList.head.getValue();
+		}
 	}
 
 	/**
@@ -150,10 +158,10 @@ public class Management implements IManagement {
 		this.numberOfOperations++;
 		
 		LinkedListNode<IMember> newHead = new LinkedListNode<IMember>(value);
-		if (this.head.isPresent()) {
-			newHead.setNext(this.head.get());
+		if (this.head != null) {
+			newHead.setNext(this.head);
 		}
-		this.head = Optional.of(newHead);
+		this.head = newHead;
 
 		this.size++;
 		return true; // TODO?
@@ -167,7 +175,7 @@ public class Management implements IManagement {
 	 */
 	@Override
 	public IMember search(long key) {
-		return this.search(member -> member.getKey() == key).orElse(null);
+		return this.search(member -> member.getKey() == key);
 	}
 
 	/**
@@ -180,7 +188,7 @@ public class Management implements IManagement {
 	@Override
 	public IMember search(String name, String firstName) {
 		return this.search(member -> member.getName().equals(name)
-				&& member.getFirstName().equals(firstName)).orElse(null);
+				&& member.getFirstName().equals(firstName));
 	}
 
 	/**
@@ -214,11 +222,11 @@ public class Management implements IManagement {
 	@Override
 	public IMember[] toArray() {
 		IMember[] array = new IMember[this.size];
-		if (!this.head.isPresent()) {
+		if (this.size() == 0) {
 			return array;
 		}
 
-		LinkedListNode<IMember> currentNode = this.head.get();
+		LinkedListNode<IMember> currentNode = this.head;
 
 		for (int index = 0; index < this.size; index++) {
 			if (reversed) {
@@ -243,4 +251,15 @@ public class Management implements IManagement {
 		this.numberOfOperations = 0;
 		return numberOfOperations;
 	}
+	
+	/**
+	 * Reset the timer and get the time difference in ns.
+	 * 
+	 * @return Nanoseconds since the last call.
+	 */
+	public long checkpoint() {
+		long nanoseconds = this.lastCheckpointNs;
+		this.lastCheckpointNs = System.nanoTime();
+		return this.lastCheckpointNs - nanoseconds;
+	}
 }