build-sys: move source files to subdirectory

[elogind.git] / src / list.h

diff --git a/src/list.h b/src/list.h
new file mode 100644 (file)
index 0000000..012dd12
--- /dev/null
+++ b/src/list.h
@@ -0,0 +1,119 @@
+/*-*- Mode: C; c-basic-offset: 8 -*-*/
+
+#ifndef foolisthfoo
+#define foolisthfoo
+
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  systemd 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
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+/* The head of the linked list. Use this in the structure that shall
+ * contain the head of the linked list */
+#define LIST_HEAD(t,name)                                               \
+        t *name
+
+/* The pointers in the linked list's items. Use this in the item structure */
+#define LIST_FIELDS(t,name)                                             \
+        t *name##_next, *name##_prev
+
+/* Initialize the list's head */
+#define LIST_HEAD_INIT(t,head)                                          \
+        do {                                                            \
+                (head) = NULL; }                                        \
+        while(false)
+
+/* Initialize a list item */
+#define LIST_INIT(t,name,item)                                          \
+        do {                                                            \
+                t *_item = (item);                                      \
+                assert(_item);                                          \
+                _item->name##_prev = _item->name##_next = NULL;         \
+        } while(false)
+
+/* Prepend an item to the list */
+#define LIST_PREPEND(t,name,head,item)                                  \
+        do {                                                            \
+                t **_head = &(head), *_item = (item);                   \
+                assert(_item);                                          \
+                if ((_item->name##_next = *_head))                      \
+                        _item->name##_next->name##_prev = _item;        \
+                _item->name##_prev = NULL;                              \
+                *_head = _item;                                         \
+        } while(false)
+
+/* Remove an item from the list */
+#define LIST_REMOVE(t,name,head,item)                                   \
+        do {                                                            \
+                t **_head = &(head), *_item = (item);                   \
+                assert(_item);                                          \
+                if (_item->name##_next)                                 \
+                        _item->name##_next->name##_prev = _item->name##_prev; \
+                if (_item->name##_prev)                                 \
+                        _item->name##_prev->name##_next = _item->name##_next; \
+                else {                                                  \
+                        assert(*_head == _item);                        \
+                        *_head = _item->name##_next;                    \
+                }                                                       \
+                _item->name##_next = _item->name##_prev = NULL;         \
+        } while(false)
+
+/* Find the head of the list */
+#define LIST_FIND_HEAD(t,name,item,head)                                \
+        do {                                                            \
+                t *_item = (item);                                      \
+                assert(_item);                                          \
+                while ((_item->name##_prev)                             \
+                       _item = _item->name##_prev;                      \
+                (head) = _item;                                         \
+        } while (false)
+
+/* Find the head of the list */
+#define LIST_FIND_TAIL(t,name,item,tail)                                \
+        do {                                                            \
+                t *_item = (item);                                      \
+                assert(_item);                                          \
+                while (_item->name##_next)                              \
+                        _item = _item->name##_next;                     \
+                (tail) = _item;                                         \
+        } while (false)
+
+/* Insert an item after another one (a = where, b = what) */
+#define LIST_INSERT_AFTER(t,name,head,a,b)                              \
+        do {                                                            \
+                t **_head = &(head), *_a = (a), *_b = (b);              \
+                assert(_b);                                             \
+                if (!_a) {                                              \
+                        if ((_b->name##_next = *_head))                 \
+                                _b->name##_next->name##_prev = _b;      \
+                        _b->name##_prev = NULL;                         \
+                        *_head = _b;                                    \
+                } else {                                                \
+                        if ((_b->name##_next = _a->name##_next))        \
+                                _b->name##_next->name##_prev = _b;      \
+                        _b->name##_prev = _a;                           \
+                        _a->name##_next = _b;                           \
+                }                                                       \
+        } while(false)
+
+#define LIST_FOREACH(name,i,head)                                       \
+        for ((i) = (head); (i); (i) = (i)->name##_next)
+
+#define LIST_FOREACH_SAFE(name,i,n,head)                                \
+        for ((i) = (head); (i) && (((n) = (i)->name##_next), 1); (i) = (n))
+
+#endif