js/src/jsclist.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
   7  * the License. You may obtain a copy of the License at
   8  * http://www.mozilla.org/MPL/
   9  *
  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
  13  * License.
  14  *
  15  * The Original Code is Mozilla Communicator client code, released
  16  * March 31, 1998.
  17  *
  18  * The Initial Developer of the Original Code is
  19  * Netscape Communications Corporation.
  20  * Portions created by the Initial Developer are Copyright (C) 1998
  21  * the Initial Developer. All Rights Reserved.
  22  *
  23  * Contributor(s):
  24  *
  25  * Alternatively, the contents of this file may be used under the terms of
  26  * either of the GNU General Public License Version 2 or later (the "GPL"),
  27  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  28  * in which case the provisions of the GPL or the LGPL are applicable instead
  29  * of those above. If you wish to allow use of your version of this file only
  30  * under the terms of either the GPL or the LGPL, and not to allow others to
  31  * use your version of this file under the terms of the MPL, indicate your
  32  * decision by deleting the provisions above and replace them with the notice
  33  * and other provisions required by the GPL or the LGPL. If you do not delete
  34  * the provisions above, a recipient may use your version of this file under
  35  * the terms of any one of the MPL, the GPL or the LGPL.
  36  *
  37  * ***** END LICENSE BLOCK ***** */
  38
  39 #ifndef jsclist_h___
  40 #define jsclist_h___
  41
  42 #include "jstypes.h"
  43
  44 /*
  45 ** Circular linked list
  46 */
  47 typedef struct JSCListStr {
  48     struct JSCListStr *next;
  49     struct JSCListStr *prev;
  50 } JSCList;
  51
  52 /*
  53 ** Insert element "_e" into the list, before "_l".
  54 */
  55 #define JS_INSERT_BEFORE(_e,_l)  \
  56     JS_BEGIN_MACRO               \
  57         (_e)->next = (_l);       \
  58         (_e)->prev = (_l)->prev; \
  59         (_l)->prev->next = (_e); \
  60         (_l)->prev = (_e);       \
  61     JS_END_MACRO
  62
  63 /*
  64 ** Insert element "_e" into the list, after "_l".
  65 */
  66 #define JS_INSERT_AFTER(_e,_l)   \
  67     JS_BEGIN_MACRO               \
  68         (_e)->next = (_l)->next; \
  69         (_e)->prev = (_l);       \
  70         (_l)->next->prev = (_e); \
  71         (_l)->next = (_e);       \
  72     JS_END_MACRO
  73
  74 /*
  75 ** Return the element following element "_e"
  76 */
  77 #define JS_NEXT_LINK(_e)         \
  78         ((_e)->next)
  79 /*
  80 ** Return the element preceding element "_e"
  81 */
  82 #define JS_PREV_LINK(_e)         \
  83         ((_e)->prev)
  84
  85 /*
  86 ** Append an element "_e" to the end of the list "_l"
  87 */
  88 #define JS_APPEND_LINK(_e,_l) JS_INSERT_BEFORE(_e,_l)
  89
  90 /*
  91 ** Insert an element "_e" at the head of the list "_l"
  92 */
  93 #define JS_INSERT_LINK(_e,_l) JS_INSERT_AFTER(_e,_l)
  94
  95 /* Return the head/tail of the list */
  96 #define JS_LIST_HEAD(_l) (_l)->next
  97 #define JS_LIST_TAIL(_l) (_l)->prev
  98
  99 /*
 100 ** Remove the element "_e" from it's circular list.
 101 */
 102 #define JS_REMOVE_LINK(_e)             \
 103     JS_BEGIN_MACRO                     \
 104         (_e)->prev->next = (_e)->next; \
 105         (_e)->next->prev = (_e)->prev; \
 106     JS_END_MACRO
 107
 108 /*
 109 ** Remove the element "_e" from it's circular list. Also initializes the
 110 ** linkage.
 111 */
 112 #define JS_REMOVE_AND_INIT_LINK(_e)    \
 113     JS_BEGIN_MACRO                     \
 114         (_e)->prev->next = (_e)->next; \
 115         (_e)->next->prev = (_e)->prev; \
 116         (_e)->next = (_e);             \
 117         (_e)->prev = (_e);             \
 118     JS_END_MACRO
 119
 120 /*
 121 ** Return non-zero if the given circular list "_l" is empty, zero if the
 122 ** circular list is not empty
 123 */
 124 #define JS_CLIST_IS_EMPTY(_l) \
 125     ((_l)->next == (_l))
 126
 127 /*
 128 ** Initialize a circular list
 129 */
 130 #define JS_INIT_CLIST(_l)  \
 131     JS_BEGIN_MACRO         \
 132         (_l)->next = (_l); \
 133         (_l)->prev = (_l); \
 134     JS_END_MACRO
 135
 136 #define JS_INIT_STATIC_CLIST(_l) \
 137     {(_l), (_l)}
 138
 139 #endif /* jsclist_h___ */