Cleanup

Assignment8/code/disk.c

@@ -75,30 +75,36 @@ void destroyDiskQueue(DiskQueue *queue) {
 	free(queue);
 }
 
-int calcDistance(int position, int destination) {
-	if (position > destination) {
-		return destination + (9999 + 1 - position);
-	} else {
-		return destination - position;
-	}
-}
-
 DiskRequest* findClosest(DiskQueue *queue, int position, double time) {
 	DiskRequest *current = queue->head;
-	DiskRequest *closest = NULL;
+	DiskRequest *next = NULL;
+	DiskRequest *first = NULL;
 	while (current != NULL) {
 		if (current->time <= time) { // Filter out requests that haven't come in yet
-			if (closest == NULL) { // If there is no closest yet, set it to the current
-				closest = current;
+			if (first == NULL) {
+				first = current;
 			} else {
-				int closestDistance = calcDistance(position, closest->position); // Distance from the closest to the current position, negative means down (bad)
-				int currentDistance = calcDistance(position, current->position); // Distance from the current to the current position, negative means down (bad
-				if (currentDistance < closestDistance) { // If the current is closer than the closest
-					closest = current;
+				if (current->position < first->position) {
+					first = current;
+				}
+			}
+			int currentDistance = current->position - position; // Distance from the current to the current position, negative means down (bad)
+			if (currentDistance > 0) { // If the current is up
+				if (next == NULL) { // If there is no next yet, set it to the current
+					next = current;
+				} else {
+					int nextDistance = next->position - position; // Distance from the next to the current position, negative means down (bad)
+					if (currentDistance < nextDistance) { // If the current is closer than the next
+						next = current;
+					}
 				}
 			}
 		}
 		current = current->next;
 	}
-	return closest;
-}
+	// If we didn't find a request that is above the current position, return the first as a fallback
+	if (next == NULL) {
+		return first;
+	}
+	return next;
+}

Assignment8/code/disk.h

@@ -26,5 +26,3 @@ DiskRequest *dequeue(DiskQueue *queue);
 DiskRequest *findClosest(DiskQueue *queue, int position, double time);
 
 void destroyDiskQueue(DiskQueue *queue);
-
-int calcDistance(int position, int destination);

Assignment8/code/main.c

@@ -92,4 +92,4 @@ int main(int argc, char **argv) {
 	destroyDiskQueue(queue);
 
 	return 0;
-}
+}