gistlist.h

此文件包含了在linux下实现tpr-tree索引的源代码

// -*- Mode: C++ -*-
//--------------------------------------------------------------------
//        GiSTlist.h
//        ----------
//
//        GiST - Generalized Search Tree 
//        June 2001 release, Aalborg University
//        
//        This file is a revised version of a part of the original 
//        libGiST release (version  0.9beta1)     
//        Copyright (c) 1996, Regents of the University of California
//

#ifndef GISTLIST_H
#define GISTLIST_H

//------------------------------------------------
//  A template list package, which is handy.

template <class T>
struct GiSTlistnode
{
  T entry;
  GiSTlistnode<T> *prev, *next;
};

//------------------------------------------------
template <class T>
class GiSTlist
{
  public:
    GiSTlist()    { front = rear = NULL; }
//  GiSTlist(const GiSTlist<T>& l) { front = l.front; rear = l.rear; }

    int IsEmpty() { return front == NULL; }

    T RemoveFront()
    {
       assert(front != NULL);
       GiSTlistnode<T> *temp = front;
       T e = front->entry;
       front = front->next;
       if (front)
           front->prev = NULL;
       else
           rear = NULL;
       delete temp;
       return e;
    }

    T RemoveRear()
    {
       assert(rear != NULL);
       GiSTlistnode<T> *temp = rear;
       T e = rear->entry;
       rear = rear->prev;
       if (rear) rear->next = NULL; else front = NULL;
       delete temp;
       return e;
    }

    void Prepend(T entry)
    {
       GiSTlistnode<T> *temp = new GiSTlistnode<T>;

       temp->entry = entry;
       temp->next = front;
       temp->prev = NULL;

       if (rear == NULL)
           rear = temp;
       else
           front->prev = temp;
       front = temp;
    }

    void Append(T entry)
    {
       GiSTlistnode<T> *temp = new GiSTlistnode<T>;

       temp->entry = entry;
       temp->prev = rear;
       temp->next = NULL;

       if (front == NULL)
           front = temp;
       else
           rear->next = temp;
       rear = temp;
    }

  private:
    GiSTlistnode<T> *front, *rear;
};

#endif