1/*-
2 * This file is provided under a dual BSD/GPLv2 license.  When using or
3 * redistributing this file, you may do so under either license.
4 *
5 * GPL LICENSE SUMMARY
6 *
7 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of version 2 of the GNU General Public License as
11 * published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
21 * The full GNU General Public License is included in this distribution
22 * in the file called LICENSE.GPL.
23 *
24 * BSD LICENSE
25 *
26 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
27 * All rights reserved.
28 *
29 * Redistribution and use in source and binary forms, with or without
30 * modification, are permitted provided that the following conditions
31 * are met:
32 *
33 *   * Redistributions of source code must retain the above copyright
34 *     notice, this list of conditions and the following disclaimer.
35 *   * Redistributions in binary form must reproduce the above copyright
36 *     notice, this list of conditions and the following disclaimer in
37 *     the documentation and/or other materials provided with the
38 *     distribution.
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
41 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
42 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
43 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
44 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
46 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
47 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
48 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
49 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
50 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
51 *
52 * $FreeBSD$
53 */
54#ifndef _SCI_SIMPLE_LIST_HEADER_
55#define _SCI_SIMPLE_LIST_HEADER_
56
57/**
58 * @file
59 *
60 * @brief This header file contains simple linked list manipulation macros.
61 *        These macros differ from the SCI_FAST_LIST in that deletion of
62 *        an element from the list is O(n).
63 *        The reason for using this implementation over the SCI_FAST_LIST
64 *        is
65 *           1) space savings as there is only a single link element instead
66 *              of the 2 link elements used in the SCI_FAST_LIST and
67 *           2) it is possible to detach the entire list from its anchor
68 *              element for processing.
69 *
70 * @note Do not use the SCI_SIMPLE_LIST if you need to remove elements from
71 *       random locations within the list use instead the SCI_FAST_LIST.
72 */
73
74
75//******************************************************************************
76//*
77//*     P U B L I C    M E T H O D S
78//*
79//******************************************************************************
80
81/**
82 * Initialize the singely linked list anchor.  The other macros require the
83 * list anchor to be properly initialized.
84 */
85#define sci_simple_list_init(anchor) \
86{ \
87   (anchor)->list_head = NULL; \
88   (anchor)->list_tail = NULL; \
89   (anchor)->list_count = 0; \
90}
91
92/**
93 * Initialze the singely linked list element. The other macros require the
94 * list element to be properly initialized.
95 */
96#define sci_simple_list_element_init(list_object, element) \
97{ \
98   (element)->next = NULL; \
99   (element)->object = (list_object); \
100}
101
102/**
103 * See if there are any list elements on this list.
104 */
105#define sci_simple_list_is_empty(anchor)  ((anchor)->list_head == NULL)
106
107/**
108 * Return a pointer to the list element at the head of the list.  The list
109 * element is not removed from the list.
110 */
111#define sci_simple_list_get_head(anchor) ((anchor)->list_head)
112
113/**
114 * Retuen a pointer to the lsit element at the tail of the list.  The list
115 * element is not removed from the list.
116 */
117#define sci_simple_list_get_tail(anchor) ((anchor)->list_tail)
118
119/**
120 * Return the count of the number of elements in this list.
121 */
122#define sci_simple_list_get_count(anchor) ((anchor)->list_count)
123
124/**
125 * Return a pointer to the list element following this list element.
126 * If this is the last element in the list then NULL is returned.
127 */
128#define sci_simple_list_get_next(element) ((element)->next)
129
130/**
131 * Return the object represented by the list element.
132 */
133#define sci_simple_list_get_object(element) ((element)->object)
134
135
136//******************************************************************************
137//*
138//*     T Y P E S
139//*
140//******************************************************************************
141
142/**
143 * @struct
144 *
145 * @brief This structure defines the list owner for singely linked list.
146 */
147typedef struct SCI_SIMPLE_LIST
148{
149   struct SCI_SIMPLE_LIST_ELEMENT *list_head;
150   struct SCI_SIMPLE_LIST_ELEMENT *list_tail;
151   U32                             list_count;
152} SCI_SIMPLE_LIST_T;
153
154/**
155 * @struct SCI_SIMPLE_LIST_ELEMENT
156 *
157 * @brief This structure defines what a singely linked list element contains.
158 */
159typedef struct SCI_SIMPLE_LIST_ELEMENT
160{
161   struct SCI_SIMPLE_LIST_ELEMENT *next;
162   void                           *object;
163} SCI_SIMPLE_LIST_ELEMENT_T;
164
165/**
166 * This method will insert the list element to the head of the list contained
167 * by the anchor.
168 *
169 * @note Pushing new elements onto a list is more efficient than inserting
170 *       them to the tail of the list though both are O(1) operations.
171 */
172INLINE
173static void sci_simple_list_insert_head(
174   SCI_SIMPLE_LIST_T * anchor,
175   SCI_SIMPLE_LIST_ELEMENT_T *element
176)
177{
178   if (anchor->list_tail == NULL)
179   {
180      anchor->list_tail = element;
181   }
182
183   element->next = anchor->list_head;
184   anchor->list_head = element;
185   anchor->list_count++;
186}
187
188/**
189 * This methos will insert the list element to the tail of the list contained
190 * by the anchor.
191 *
192 * @param[in, out] anchor this is the list into which the element is to be
193 *                 inserted
194 * @param[in] element this is the element which to insert into the list.
195 *
196 * @note Pushing new elements onto a list is more efficient than inserting
197 *       them to the tail of the list though both are O(1) operations.
198 */
199INLINE
200static void sci_simple_list_insert_tail(
201   SCI_SIMPLE_LIST_T * anchor,
202   SCI_SIMPLE_LIST_ELEMENT_T *element
203)
204{
205   if (anchor->list_tail == NULL)
206   {
207      anchor->list_head = element;
208   }
209   else
210   {
211      anchor->list_tail->next = element;
212   }
213
214   anchor->list_tail = element;
215   anchor->list_count++;
216}
217
218/**
219 * This method will remove the list element from the anchor and return the
220 * object pointed to by that list element.
221 *
222 * @param[in, out] anchor this is the list into which the element is to be
223 *                 inserted
224 *
225 * @return the list element at the head of the list.
226 */
227INLINE
228static void * sci_simple_list_remove_head(
229   SCI_SIMPLE_LIST_T * anchor
230)
231{
232   void * object = NULL;
233
234   if (anchor->list_head != NULL)
235   {
236      object = anchor->list_head->object;
237
238      anchor->list_head = anchor->list_head->next;
239
240      if (anchor->list_head == NULL)
241      {
242         anchor->list_tail = NULL;
243      }
244
245      anchor->list_count--;
246   }
247
248   return object;
249}
250
251/**
252 * Move all the list elements from source anchor to the dest anchor.
253 * The source anchor will have all of its elements removed making it
254 * an empty list and the dest anchor will contain all of the source
255 * and dest list elements.
256 *
257 * @param[in, out] dest_anchor this is the list into which all elements from
258 *                 the source list are to be moved.
259 * @param[in, out] source_anchor this is the list which is to be moved to the
260 *                 destination list.  This list will be empty on return.
261 *
262 * @return the list element at the head of the list.
263 * @note If the destination has list elements use the insert at head
264 *       or tail routines instead.
265 */
266INLINE
267static void sci_simple_list_move_list(
268   SCI_SIMPLE_LIST_T * dest_anchor,
269   SCI_SIMPLE_LIST_T * source_anchor
270)
271{
272   *dest_anchor = *source_anchor;
273
274   sci_simple_list_init(source_anchor);
275}
276
277/**
278 * This method will insert the list elements from the source anchor to the
279 * destination list before all previous elements on the destination list.
280 *
281 * @param[in, out] dest_anchor this is the list into which all elements from
282 *                 the source list are to be moved. The destination list will
283 *                 now contain both sets of list elements.
284 * @param[in, out] source_anchor this is the list which is to be moved to the
285 *                 destination list.  This list will be empty on return.
286 */
287INLINE
288static void sci_simple_list_insert_list_at_head(
289   SCI_SIMPLE_LIST_T * dest_anchor,
290   SCI_SIMPLE_LIST_T * source_anchor
291)
292{
293   if (!sci_simple_list_is_empty(source_anchor))
294   {
295      if (sci_simple_list_is_empty(dest_anchor))
296      {
297         // Destination is empty just copy the source on over
298         *dest_anchor = *source_anchor;
299      }
300      else
301      {
302         source_anchor->list_tail->next = dest_anchor->list_head;
303         dest_anchor->list_head = source_anchor->list_head;
304         dest_anchor->list_count += source_anchor->list_count;
305      }
306
307      // Wipe the source list to make sure the list elements can not be accessed
308      // from two seperate lists at the same time.
309      sci_simple_list_init(source_anchor);
310   }
311}
312
313/**
314 * This method will insert the list elements from the source anchor to the
315 * destination anchor after all list elements on the destination anchor.
316 *
317 * @param[in, out] dest_anchor this is the list into which all elements from
318 *                 the source list are to be moved. The destination list will
319 *                 contain both the source and destination list elements.
320 * @param[in, out] source_anchor this is the list which is to be moved to the
321 *                 destination list.  This list will be empty on return.
322 */
323INLINE
324static void sci_simple_list_insert_list_at_tail(
325   SCI_SIMPLE_LIST_T * dest_anchor,
326   SCI_SIMPLE_LIST_T * source_anchor
327)
328{
329   if (!sci_simple_list_is_empty(source_anchor))
330   {
331      if (sci_simple_list_is_empty(dest_anchor))
332      {
333         // Destination is empty just copy the source on over
334         *dest_anchor = *source_anchor;
335      }
336      else
337      {
338         // If the source list is empty the desination list is the result.
339         dest_anchor->list_tail->next = source_anchor->list_head;
340         dest_anchor->list_tail = source_anchor->list_tail;
341         dest_anchor->list_count += source_anchor->list_count;
342      }
343
344      // Wipe the source list to make sure the list elements can not be accessed
345      // from two seperate lists at the same time.
346      sci_simple_list_init(source_anchor);
347   }
348}
349
350#endif // _SCI_SIMPLE_LIST_HEADER_
351