Add circular, singly-linked list library
This commit is contained in:
George Oikonomou
parent
9dab37eae4
commit
b82ca1a5ef
|
|
@ -0,0 +1,157 @@
|
|||
/*
|
||||
* Copyright (c) 2017, George Oikonomou - http://www.spd.gr
|
||||
* Copyright (c) 2017, James Pope
|
||||
* All rights reserved.
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
*
|
||||
* 1. Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* 2. Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in the
|
||||
* documentation and/or other materials provided with the distribution.
|
||||
* 3. Neither the name of the copyright holder nor the names of its
|
||||
* contributors may be used to endorse or promote products derived
|
||||
* from this software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
||||
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
||||
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
||||
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
|
||||
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
||||
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
|
||||
* OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
*/
|
||||
/*---------------------------------------------------------------------------*/
|
||||
/**
|
||||
* \addtogroup circular-singly-linked-list
|
||||
* @{
|
||||
*
|
||||
* \file
|
||||
* Implementation of circular singly linked lists
|
||||
*/
|
||||
/*---------------------------------------------------------------------------*/
|
||||
#include "contiki.h"
|
||||
#include "lib/circular-list.h"
|
||||
|
||||
#include <stdint.h>
|
||||
#include <stdbool.h>
|
||||
#include <string.h>
|
||||
/*---------------------------------------------------------------------------*/
|
||||
struct cl {
|
||||
struct cl *next;
|
||||
};
|
||||
/*---------------------------------------------------------------------------*/
|
||||
void
|
||||
circular_list_init(circular_list_t cl)
|
||||
{
|
||||
*cl = NULL;
|
||||
}
|
||||
/*---------------------------------------------------------------------------*/
|
||||
void *
|
||||
circular_list_head(circular_list_t cl)
|
||||
{
|
||||
return *cl;
|
||||
}
|
||||
/*---------------------------------------------------------------------------*/
|
||||
void *
|
||||
circular_list_tail(circular_list_t cl)
|
||||
{
|
||||
struct cl *this;
|
||||
|
||||
if(*cl == NULL) {
|
||||
return NULL;
|
||||
}
|
||||
|
||||
for(this = *cl; this->next != *cl; this = this->next);
|
||||
|
||||
return this;
|
||||
}
|
||||
/*---------------------------------------------------------------------------*/
|
||||
void
|
||||
circular_list_remove(circular_list_t cl, void *element)
|
||||
{
|
||||
struct cl *this, *previous;
|
||||
|
||||
if(*cl == NULL) {
|
||||
return;
|
||||
}
|
||||
|
||||
/*
|
||||
* We start traversing from the second element.
|
||||
* The head will be visited last. We always update the list's head after
|
||||
* removal, just in case we have just removed the head.
|
||||
*/
|
||||
previous = *cl;
|
||||
this = previous->next;
|
||||
|
||||
do {
|
||||
if(this == element) {
|
||||
previous->next = this->next;
|
||||
*cl = this->next == this ? NULL : previous;
|
||||
return;
|
||||
}
|
||||
previous = this;
|
||||
this = this->next;
|
||||
} while(this != ((struct cl *)*cl)->next);
|
||||
}
|
||||
/*---------------------------------------------------------------------------*/
|
||||
void
|
||||
circular_list_add(circular_list_t cl, void *element)
|
||||
{
|
||||
struct cl *head;
|
||||
|
||||
if(element == NULL) {
|
||||
return;
|
||||
}
|
||||
|
||||
/* Don't add twice */
|
||||
circular_list_remove(cl, element);
|
||||
|
||||
head = *cl;
|
||||
|
||||
if(head == NULL) {
|
||||
/* If the list was empty, we update the new element to point to itself */
|
||||
((struct cl *)element)->next = element;
|
||||
} else {
|
||||
/* If the list exists, we add the new element between the current head and
|
||||
* the previously second element. */
|
||||
((struct cl *)element)->next = head->next;
|
||||
head->next = element;
|
||||
}
|
||||
|
||||
/* In all cases, the new element becomes the list's new head */
|
||||
*cl = element;
|
||||
}
|
||||
/*---------------------------------------------------------------------------*/
|
||||
unsigned long
|
||||
circular_list_length(circular_list_t cl)
|
||||
{
|
||||
unsigned long len = 1;
|
||||
struct cl *this;
|
||||
|
||||
if(circular_list_is_empty(cl)) {
|
||||
return 0;
|
||||
}
|
||||
|
||||
for(this = *cl; this->next != *cl; this = this->next) {
|
||||
len++;
|
||||
}
|
||||
|
||||
return len;
|
||||
}
|
||||
/*---------------------------------------------------------------------------*/
|
||||
bool
|
||||
circular_list_is_empty(circular_list_t cl)
|
||||
{
|
||||
return *cl == NULL ? true : false;
|
||||
}
|
||||
/*---------------------------------------------------------------------------*/
|
||||
/** @} */
|
||||
|
|
@ -0,0 +1,155 @@
|
|||
/*
|
||||
* Copyright (c) 2017, George Oikonomou - http://www.spd.gr
|
||||
* Copyright (c) 2017, James Pope
|
||||
* All rights reserved.
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
*
|
||||
* 1. Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* 2. Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in the
|
||||
* documentation and/or other materials provided with the distribution.
|
||||
* 3. Neither the name of the copyright holder nor the names of its
|
||||
* contributors may be used to endorse or promote products derived
|
||||
* from this software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
||||
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
||||
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
||||
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
|
||||
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
||||
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
|
||||
* OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
*/
|
||||
/*---------------------------------------------------------------------------*/
|
||||
/** \addtogroup data
|
||||
* @{
|
||||
*
|
||||
* \defgroup circular-singly-linked-list Circular, singly-linked list
|
||||
*
|
||||
* This library provides functions for the creation and manipulation of
|
||||
* circular, singly-linked lists.
|
||||
*
|
||||
* A circular, singly-linked list is declared using the CIRCULAR_LIST macro.
|
||||
* Elements must be allocated by the calling code and must be of a C struct
|
||||
* datatype. In this struct, the first field must be a pointer called \e next.
|
||||
* This field will be used by the library to maintain the list. Application
|
||||
* code must not modify this field directly.
|
||||
*
|
||||
* Functions that modify the list (add / remove) will, in the general case,
|
||||
* update the list's head and item order. If you call one of these functions
|
||||
* as part of a list traversal, it is advised to stop / restart traversing
|
||||
* after the respective function returns.
|
||||
* @{
|
||||
*/
|
||||
/*---------------------------------------------------------------------------*/
|
||||
#ifndef CIRCULAR_LIST_H_
|
||||
#define CIRCULAR_LIST_H_
|
||||
/*---------------------------------------------------------------------------*/
|
||||
#include "contiki.h"
|
||||
|
||||
#include <stdint.h>
|
||||
#include <stdbool.h>
|
||||
#include <string.h>
|
||||
/*---------------------------------------------------------------------------*/
|
||||
/**
|
||||
* \brief Define a circular, singly-linked list.
|
||||
*
|
||||
* This macro defines a circular, singly-linked list.
|
||||
*
|
||||
* The datatype for elements must be a C struct. The struct's first member must
|
||||
* be a pointer called \e next. This is used internally by the library to
|
||||
* maintain data structure integrity and must not be modified directly by
|
||||
* application code.
|
||||
*
|
||||
* \param name The name of the circular, singly-linked list.
|
||||
*/
|
||||
#define CIRCULAR_LIST(name) \
|
||||
static void *name##_circular_list = NULL; \
|
||||
static circular_list_t name = (circular_list_t)&name##_circular_list
|
||||
/*---------------------------------------------------------------------------*/
|
||||
/**
|
||||
* \brief The circular, singly-linked list datatype
|
||||
*/
|
||||
typedef void **circular_list_t;
|
||||
/*---------------------------------------------------------------------------*/
|
||||
/**
|
||||
* \brief Initialise a circular, singly-linked list.
|
||||
* \param cl The circular, singly-linked list.
|
||||
*/
|
||||
void circular_list_init(circular_list_t cl);
|
||||
|
||||
/**
|
||||
* \brief Return the tail of a circular, singly-linked list.
|
||||
* \param cl The circular, singly-linked list.
|
||||
* \return A pointer to the list's head, or NULL if the list is empty
|
||||
*/
|
||||
void *circular_list_head(circular_list_t cl);
|
||||
|
||||
/**
|
||||
* \brief Return the tail of a circular, singly-linked list.
|
||||
* \param cl The circular, singly-linked list.
|
||||
* \return A pointer to the list's tail, or NULL if the list is empty
|
||||
*/
|
||||
void *circular_list_tail(circular_list_t cl);
|
||||
|
||||
/**
|
||||
* \brief Add an element to a circular, singly-linked list.
|
||||
* \param cl The circular, singly-linked list.
|
||||
* \param element A pointer to the element to be added.
|
||||
*
|
||||
* The caller should make no assumptions as to the position in the list of the
|
||||
* new element.
|
||||
*
|
||||
* After this function returns, the list's head is not guaranteed to be the
|
||||
* same as it was before the addition.
|
||||
*
|
||||
* Calling this function will update the list's head and item order. If you
|
||||
* call this function as part of a list traversal, it is advised to stop
|
||||
* traversing after this function returns.
|
||||
*/
|
||||
void circular_list_add(circular_list_t cl, void *element);
|
||||
|
||||
/**
|
||||
* \brief Remove an element from a circular, singly-linked list.
|
||||
* \param cl The circular, singly-linked list.
|
||||
* \param element A pointer to the element to be removed.
|
||||
*
|
||||
* After this function returns, the list's head is not guaranteed to be the
|
||||
* same as it was before the addition.
|
||||
*
|
||||
* Calling this function will update the list's head and item order. If you
|
||||
* call this function as part of a list traversal, it is advised to stop
|
||||
* traversing after this function returns.
|
||||
*/
|
||||
void circular_list_remove(circular_list_t cl, void *element);
|
||||
|
||||
/**
|
||||
* \brief Get the length of a circular, singly-linked list.
|
||||
* \param cl The circular, singly-linked list.
|
||||
* \return The number of elements in the list
|
||||
*/
|
||||
unsigned long circular_list_length(circular_list_t cl);
|
||||
|
||||
/**
|
||||
* \brief Determine whether a circular, singly-linked list is empty.
|
||||
* \param cl The circular, singly-linked list.
|
||||
* \retval true The list is empty
|
||||
* \retval false The list is not empty
|
||||
*/
|
||||
bool circular_list_is_empty(circular_list_t cl);
|
||||
/*---------------------------------------------------------------------------*/
|
||||
#endif /* CIRCULAR_LIST_H_ */
|
||||
/*---------------------------------------------------------------------------*/
|
||||
/**
|
||||
* @}
|
||||
* @}
|
||||
*/
|
||||
Loading…
Reference in New Issue