core/sql/sort/List.cpp

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#include "List.h"
#include "Const.h"
#include "ex_ex.h"

#if !defined( FORDEBUG ) && !defined( NDEBUG )
#define NDEBUG 1
#endif

template <class T>
ListNode<T>::ListNode(T thing) : next(NULL), item(thing) {

}

template <class T>
void ListNode<T>::deleteNode() {
  delete item;
}

template <class T>
List<T>::List() : head(NULL), tail(NULL), numItems(0) {

}

template <class T>
List<T>::~List() {
  ListNode<T> *temp;
  for (Int32 i =0; i < numItems; i++) {
    temp = head;
    head = temp->next;
    delete temp;
  }
  tail = NULL;
}

template <class T>
void List<T>::append(T item, CollHeap* heap) {

  ListNode<T> *temp = new (heap) ListNode<T>(item);
  if (numItems == 0) {
    head = temp;
  }
  else {
    tail->next = temp;
  }
  tail = temp;
  numItems++;
}

template <class T>
void List<T>::prepend(T item, CollHeap* heap) {

  ListNode<T> *temp = new (heap) ListNode<T>(item);
  if (numItems == 0) {
    tail = temp;
  }
  else {
   temp->next = head;
  }
  head = temp;
  numItems++;
}

template <class T>
void List<T>::deleteList() {
  
  ex_assert(numItems > 0, "List<T>::deleteList(), numItems <=0");
  ListNode<T> *temp; 
  while ( head != NULL) {
    temp = head;
    head = temp->next;
    temp->deleteNode();
    delete temp;
    numItems--;
  }
  tail = NULL;
}

template <class T>
T List<T>::first() {
  
  ex_assert(numItems > 0, "T List<T>::first(), numItems<=0");

  ListNode<T> *temp = head;
  
  if (numItems == 1) {
    head = tail = NULL;
  }
  else {
    head = temp->next;
  }
  numItems--;
  T temp2 = temp->item;
  delete temp;
  return temp2;
}