120 lines
3.4 KiB
C
120 lines
3.4 KiB
C
// Copyright(c) 2006 to 2020 ZettaScale Technology and others
|
|
//
|
|
// This program and the accompanying materials are made available under the
|
|
// terms of the Eclipse Public License v. 2.0 which is available at
|
|
// http://www.eclipse.org/legal/epl-2.0, or the Eclipse Distribution License
|
|
// v. 1.0 which is available at
|
|
// http://www.eclipse.org/org/documents/edl-v10.php.
|
|
//
|
|
// SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
|
|
|
|
#ifndef DDSRT_CIRCLIST_H
|
|
#define DDSRT_CIRCLIST_H
|
|
|
|
/**
|
|
* @file circlist.h
|
|
*
|
|
* Circular doubly linked list implementation.
|
|
*/
|
|
|
|
#include <stdbool.h>
|
|
#include <stdint.h>
|
|
#include "dds/export.h"
|
|
|
|
#if defined (__cplusplus)
|
|
extern "C" {
|
|
#endif
|
|
|
|
/**
|
|
* @brief Macro to get the pointer to the user node, see @ref ddsrt_circlist_elem for an example.
|
|
*/
|
|
#define DDSRT_FROM_CIRCLIST(typ_, member_, cle_) ((typ_ *) ((char *) (cle_) - offsetof (typ_, member_)))
|
|
|
|
/** @brief the circular doubly linked list */
|
|
struct ddsrt_circlist {
|
|
struct ddsrt_circlist_elem *latest; /**< pointer to latest inserted element */
|
|
};
|
|
|
|
/// @brief The circlist element is the basic element of circular doubly linked list structure.
|
|
///
|
|
/// To store user data in the list, the element must be embedded in a user element, which is a struct containing the user data.
|
|
/// All API calls with an element as input or output, deal with the circlist element. Example:
|
|
/// @code{.c}
|
|
/// typedef struct num_s{ // user element
|
|
/// uint64_t val; // user data
|
|
/// ddsrt_circlist_elem elem;
|
|
/// }num_t;
|
|
/// @endcode
|
|
///
|
|
/// For functions like @ref ddsrt_circlist_latest, this means that to get a pointer to the user element, you can use the macro @ref DDSRT_FROM_CIRCLIST :
|
|
/// @code{.c}
|
|
/// num_t* num = DDSRT_FROM_CIRCLIST(num_t, elem, ddsrt_circlist_latest(listptr));
|
|
/// @endcode
|
|
struct ddsrt_circlist_elem {
|
|
struct ddsrt_circlist_elem *next;
|
|
struct ddsrt_circlist_elem *prev;
|
|
};
|
|
|
|
/**
|
|
* @brief initialize the list
|
|
*
|
|
* @param[out] list the circular list
|
|
*/
|
|
void ddsrt_circlist_init (struct ddsrt_circlist *list);
|
|
|
|
/**
|
|
* @brief check whether the list is empty
|
|
*
|
|
* @param[in] list the circular list
|
|
* @return true if empty, false if not empty
|
|
*/
|
|
bool ddsrt_circlist_isempty (const struct ddsrt_circlist *list);
|
|
|
|
/**
|
|
* @brief append an element to the list
|
|
*
|
|
* @param[in,out] list the circular list
|
|
* @param[in] elem the element to append
|
|
*
|
|
* See @ref ddsrt_circlist_remove
|
|
*/
|
|
void ddsrt_circlist_append (struct ddsrt_circlist *list, struct ddsrt_circlist_elem *elem);
|
|
|
|
/**
|
|
* @brief remove an element from the list
|
|
*
|
|
* The user is still responsible for freeing the memory associated with the element.
|
|
*
|
|
* @param[in,out] list the circular list
|
|
* @param[in] elem the element to append
|
|
*
|
|
* See @ref ddsrt_circlist_append
|
|
*/
|
|
void ddsrt_circlist_remove (struct ddsrt_circlist *list, struct ddsrt_circlist_elem *elem);
|
|
|
|
/**
|
|
* @brief get the oldest (earliest appended) element
|
|
*
|
|
* @param[in] list the circular list
|
|
* @return pointer to the oldest element
|
|
*
|
|
* See @ref ddsrt_circlist_latest, @ref ddsrt_circlist_elem
|
|
*/
|
|
struct ddsrt_circlist_elem *ddsrt_circlist_oldest (const struct ddsrt_circlist *list);
|
|
|
|
/**
|
|
* @brief get the latest (most recently appended) element
|
|
*
|
|
* @param[in] list the circular list
|
|
* @return pointer to the latest element
|
|
*
|
|
* See @ref ddsrt_circlist_oldest, @ref ddsrt_circlist_elem
|
|
*/
|
|
struct ddsrt_circlist_elem *ddsrt_circlist_latest (const struct ddsrt_circlist *list);
|
|
|
|
#if defined(__cplusplus)
|
|
}
|
|
#endif
|
|
|
|
#endif /* DDSRT_CIRCLIST_H */
|