shared: add NMCListElem

Sometimes, we want to use CList to track a simple data item. But contrary
to GList/GSList, we need to define a structure to hold the data pointer
and the CList member.

Add a generic NMCListElem type that can be used for such simple uses.

Before you ask: why not use GList/GSList? Because even simple operations
like g_list_append() is O(n), which kinda defeats the purpose of having
a doubly linked list.

This code is added to a new header file nm-c-list.h, the reason is that
there is no other good place:
  - "nm-utils/c-list.h" is a clone of upstream, it should not deviate.
  - "nm-utils/c-list-util.h" contains our utils functions for c-list.h
    but should be plain C, independent of glib.
  - "nm-utils/nm-shared-utils.h" contains our glib related utilities,
    but it should not drag in "c-list.h".
So, "nm-c-list.h" is a utility libray that extends "c-list.h" and
requires glib.
This commit is contained in:
Thomas Haller 2017-12-19 14:27:18 +01:00
parent 4ccfa7a79a
commit 2aad517b0b
2 changed files with 75 additions and 0 deletions

View file

@ -4498,6 +4498,7 @@ EXTRA_DIST += \
shared/nm-utils/c-list-util.c \
shared/nm-utils/c-list-util.h \
shared/nm-utils/gsystem-local-alloc.h \
shared/nm-utils/nm-c-list.h \
shared/nm-utils/nm-compat.c \
shared/nm-utils/nm-compat.h \
shared/nm-utils/nm-glib.h \

View file

@ -0,0 +1,74 @@
/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */
/* NetworkManager -- Network link manager
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301 USA.
*
* (C) Copyright 2014 Red Hat, Inc.
*/
#ifndef __NM_C_LIST_H__
#define __NM_C_LIST_H__
#include "c-list.h"
/*****************************************************************************/
typedef struct {
CList lst;
void *data;
} NMCListElem;
static inline NMCListElem *
nm_c_list_elem_new_stale (void *data)
{
NMCListElem *elem;
elem = g_slice_new (NMCListElem);
elem->data = data;
return elem;
}
static inline void *
nm_c_list_elem_get (CList *lst)
{
if (!lst)
return NULL;
return c_list_entry (lst, NMCListElem, lst)->data;
}
static inline void
nm_c_list_elem_free (NMCListElem *elem)
{
if (elem) {
c_list_unlink_stale (&elem->lst);
g_slice_free (NMCListElem, elem);
}
}
static inline void
nm_c_list_elem_free_all (CList *head, GDestroyNotify free_fcn)
{
NMCListElem *elem;
while ((elem = c_list_first_entry (head, NMCListElem, lst))) {
if (free_fcn)
free_fcn (elem->data);
c_list_unlink_stale (&elem->lst);
g_slice_free (NMCListElem, elem);
}
}
#endif /* __NM_C_LIST_H__ */