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Cache improvement #56

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Cache improvement #56

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141 changes: 92 additions & 49 deletions LinkedList.h
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Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,9 @@ struct ListNode
{
T data;
ListNode<T> *next;

ListNode<T>(ListNode<T>* _next = nullptr) : next(_next) {}
ListNode<T>(const T _v, ListNode<T>* _next = nullptr) : data(_v), next(_next) {}
};

template <typename T>
Expand All @@ -31,11 +34,8 @@ class LinkedList{
ListNode<T> *last;

// Helps "get" method, by saving last position
ListNode<T> *lastNodeGot;
int lastIndexGot;
// isCached should be set to FALSE
// everytime the list suffer changes
bool isCached;
ListNode<T> *lastNodeGot = nullptr;
int lastIndexGot=0; // cached node index

ListNode<T>* getNode(int index);

Expand All @@ -49,7 +49,7 @@ class LinkedList{
/*
Returns current size of LinkedList
*/
virtual int size();
virtual int size() const;
/*
Adds a T object in the specified index;
Unlink and link the LinkedList correcly;
Expand Down Expand Up @@ -91,6 +91,27 @@ class LinkedList{
*/
virtual T get(int index);

/*
Get first element of the list;
Return Element if accessible,
else, return false;
*/
virtual T head();

/*
Get last element of the list;
Return Element if accessible,
else, return false;
*/
virtual T tail();


/*
Return true if element with specified index exist
note: this works faster than (uncached) get(index)
*/
virtual bool exist(int index) const;

/*
Clear the entire array
*/
Expand All @@ -112,29 +133,24 @@ class LinkedList{
template<typename T>
LinkedList<T>::LinkedList()
{
root=NULL;
last=NULL;
root=nullptr;
last=nullptr;
_size=0;

lastNodeGot = root;
lastIndexGot = 0;
isCached = false;
}

// Clear Nodes and free Memory
template<typename T>
LinkedList<T>::~LinkedList()
{
ListNode<T>* tmp;
while(root!=NULL)
while(root)
{
tmp=root;
root=root->next;
delete tmp;
}
last = NULL;
last = nullptr;
_size=0;
isCached = false;
}

/*
Expand All @@ -149,7 +165,7 @@ ListNode<T>* LinkedList<T>::getNode(int index){

// Check if the node trying to get is
// immediatly AFTER the previous got one
if(isCached && lastIndexGot <= index){
if(lastIndexGot > 0 && lastIndexGot <= index){
_pos = lastIndexGot;
current = lastNodeGot;
}
Expand All @@ -162,7 +178,6 @@ ListNode<T>* LinkedList<T>::getNode(int index){

// Check if the object index got is the same as the required
if(_pos == index){
isCached = true;
lastIndexGot = index;
lastNodeGot = current;

Expand All @@ -173,7 +188,7 @@ ListNode<T>* LinkedList<T>::getNode(int index){
}

template<typename T>
int LinkedList<T>::size(){
int LinkedList<T>::size() const {
return _size;
}

Expand All @@ -186,44 +201,42 @@ LinkedList<T>::LinkedList(int sizeIndex, T _t){

template<typename T>
bool LinkedList<T>::add(int index, T _t){
if (index<0)
return false;

if(index >= _size)
return add(_t);

if(index == 0)
return unshift(_t);

ListNode<T> *tmp = new ListNode<T>(),
*_prev = getNode(index-1);
tmp->data = _t;
tmp->next = _prev->next;
_prev->next = tmp;
lastIndexGot = index;
ListNode<T> *_prev = getNode(--index);

_prev->next = new ListNode<T>(_t, _prev->next);
lastNodeGot = _prev->next;

_size++;
isCached = false;

return true;
}

template<typename T>
bool LinkedList<T>::add(T _t){

ListNode<T> *tmp = new ListNode<T>();
tmp->data = _t;
tmp->next = NULL;

if(root){
// Already have elements inserted
last->next = tmp;
last = tmp;
last->next = new ListNode<T>(_t);
last = last->next;
}else{
// First element being inserted
root = tmp;
last = tmp;
root = new ListNode<T>(_t);
last = root;
}

_size++;
isCached = false;
lastIndexGot = _size;
lastNodeGot = last;

return true;
}
Expand All @@ -234,13 +247,12 @@ bool LinkedList<T>::unshift(T _t){
if(_size == 0)
return add(_t);

ListNode<T> *tmp = new ListNode<T>();
tmp->next = root;
tmp->data = _t;
root = tmp;
root = new ListNode<T>(_t, root);

_size++;
isCached = false;

lastIndexGot = 0;
lastNodeGot = root;

return true;
}
Expand All @@ -266,22 +278,26 @@ T LinkedList<T>::pop(){
if(_size <= 0)
return T();

isCached = false;

if(_size >= 2){
if(_size > 1){
ListNode<T> *tmp = getNode(_size - 2);
T ret = tmp->next->data;
delete(tmp->next);
tmp->next = NULL;
tmp->next = nullptr;
last = tmp;
lastNodeGot = tmp;
_size--;
lastIndexGot = _size;
--lastIndexGot;
return ret;
}else{
// Only one element left on the list
T ret = root->data;
delete(root);
root = NULL;
last = NULL;
root = nullptr;
last = nullptr;
lastNodeGot = nullptr;
lastIndexGot = 0;
_size = 0;
return ret;
}
Expand All @@ -297,8 +313,9 @@ T LinkedList<T>::shift(){
T ret = root->data;
delete(root);
root = _next;
_size --;
isCached = false;
--_size;
lastIndexGot = 0;
lastNodeGot = root;

return ret;
}else{
Expand All @@ -323,13 +340,14 @@ T LinkedList<T>::remove(int index){
return pop();
}

ListNode<T> *tmp = getNode(index - 1);
ListNode<T> *tmp = getNode(--index);
ListNode<T> *toDelete = tmp->next;
T ret = toDelete->data;
tmp->next = tmp->next->next;
delete(toDelete);
_size--;
isCached = false;
lastIndexGot = index;
lastNodeGot = tmp;
return ret;
}

Expand Down Expand Up @@ -362,7 +380,7 @@ void LinkedList<T>::sort(int (*cmp)(T &, T &)){
if(!a_end->next ) {
if(joinPoint == &root) {
last = a_end;
isCached = false;
lastIndexGot = 0;
return;
}
else {
Expand Down Expand Up @@ -416,4 +434,29 @@ ListNode<T>* LinkedList<T>::findEndOfSortedString(ListNode<T> *p, int (*cmp)(T &
return p;
}

#endif
template<typename T>
T LinkedList<T>::head(){
if(_size>0)
return root->data;

return T();
}

template<typename T>
T LinkedList<T>::tail(){
if(_size>0)
return last->data;

return T();
}

template<typename T>
bool LinkedList<T>::exist(int index) const {
if (_size>0 && index >= 0 && index < _size)
return true;

return false;
}


#endif
49 changes: 49 additions & 0 deletions tests.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -301,6 +301,52 @@ void GivenThreeInList_WhenClearIsCalled_ThenListEmpty()
assert(list.size() == 0);
}

// test head() method
void GivenTwoInList_WhenHeadIsCalled_ThenReturnsData()
{
//Arrange
LinkedList<int> list = LinkedList<int>();
list.add(0);
list.add(1);

//Assert
assert(list.head() == 0);
}

// test tail() method
void GivenTwoInList_WhenTailIsCalled_ThenReturnsData()
{
//Arrange
LinkedList<int> list = LinkedList<int>();
list.add(0);
list.add(1);

//Assert
assert(list.tail() == 1);
}

// test exist() method
void GivenThreeNodesInList_WhenExistCalled_ReturnsVarious()
{
//Arrange
LinkedList<int> list = LinkedList<int>();
//Act Assert
assert(list.exist(-1) == false);
assert(list.exist(0) == false);
assert(list.exist(1) == false);

list.add(1);
assert(list.exist(-1) == false);
assert(list.exist(0) == true);
assert(list.exist(1) == false);

list.add(2);
assert(list.exist(-1) == false);
assert(list.exist(0) == true);
assert(list.exist(1) == true);
}


int main()
{
GivenNothingInList_WhenSizeCalled_Returns0();
Expand Down Expand Up @@ -328,6 +374,9 @@ int main()
GivenThreeNodesInList_WhenGetIsCalled_ThenReturnsData();
GivenNothingInList_WhenClearIsCalled_ThenSizeUnchanged();
GivenThreeInList_WhenClearIsCalled_ThenListEmpty();
GivenTwoInList_WhenHeadIsCalled_ThenReturnsData();
GivenTwoInList_WhenTailIsCalled_ThenReturnsData();
GivenThreeNodesInList_WhenExistCalled_ReturnsVarious();

std::cout<< "Tests pass"<< std::endl;
}