CellularList.h

/*
 * Copyright (c) 2017, Arm Limited and affiliates.
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 
#ifndef CELLULAR_LIST_H_
#define CELLULAR_LIST_H_
 
#include <stddef.h>
 
namespace mbed {
 
/** Class CellularList
 *
 *  Templated linked list class for common usage.
 *
 */
template <class T> class CellularList {
private:
    T *_head, *_tail;
public:
    CellularList()
    {
        _head = NULL;
        _tail = NULL;
    }
 
    ~CellularList()
    {
        T *temp = _head;
        while (temp) {
            _head = _head->next;
            delete temp;
            temp = _head;
        }
    }
 
    T *add_new()
    {
        T *temp = new T;
        temp->next = NULL;
        if (_head == NULL) {
            _head = temp;
        } else {
            _tail->next = temp;
        }
        _tail = temp;
 
        return _tail;
    }
 
    void delete_last()
    {
        T *previous = NULL;
        T *current = _head;
 
        if (!current) {
            return;
        }
 
        while (current->next != NULL) {
            previous = current;
            current = current->next;
        }
 
        if (previous) {
            _tail = previous;
            previous->next = NULL;
        } else {
            _head = NULL;
            _tail = NULL;
        }
 
        delete current;
    }
 
    int count()
    {
        T *item = _head;
        int n = 0;
        while (item) {
            item = item->next;
            n++;
        }
        return n;
    }
 
    T *dequeue()
    {
        if (!_head) {
            return NULL;
        }
        T *temp = _head;
        _head = _head->next;
        return temp;
    }
 
    void delete_all()
    {
        T *temp = _head;
        while (temp) {
            _head = _head->next;
            delete temp;
            temp = _head;
        }
        _tail = NULL;
    }
 
 
    T *get_head()
    {
        return _head;
    }
};
 
} // namespace mbed
 
#endif // CELLULAR_LIST_H_