js/src/jsclist.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   2  * vim: set ts=8 sts=4 et sw=4 tw=99:
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef jsclist_h
   8 #define jsclist_h
   9
  10 #include "jstypes.h"
  11
  12 /*
  13 ** Circular linked list
  14 */
  15 typedef struct JSCListStr {
  16     struct JSCListStr* next;
  17     struct JSCListStr* prev;
  18 } JSCList;
  19
  20 /*
  21 ** Insert element "_e" into the list, before "_l".
  22 */
  23 #define JS_INSERT_BEFORE(_e,_l)  \
  24     JS_BEGIN_MACRO               \
  25         (_e)->next = (_l);       \
  26         (_e)->prev = (_l)->prev; \
  27         (_l)->prev->next = (_e); \
  28         (_l)->prev = (_e);       \
  29     JS_END_MACRO
  30
  31 /*
  32 ** Insert element "_e" into the list, after "_l".
  33 */
  34 #define JS_INSERT_AFTER(_e,_l)   \
  35     JS_BEGIN_MACRO               \
  36         (_e)->next = (_l)->next; \
  37         (_e)->prev = (_l);       \
  38         (_l)->next->prev = (_e); \
  39         (_l)->next = (_e);       \
  40     JS_END_MACRO
  41
  42 /*
  43 ** Return the element following element "_e"
  44 */
  45 #define JS_NEXT_LINK(_e)         \
  46         ((_e)->next)
  47 /*
  48 ** Return the element preceding element "_e"
  49 */
  50 #define JS_PREV_LINK(_e)         \
  51         ((_e)->prev)
  52
  53 /*
  54 ** Append an element "_e" to the end of the list "_l"
  55 */
  56 #define JS_APPEND_LINK(_e,_l) JS_INSERT_BEFORE(_e,_l)
  57
  58 /*
  59 ** Insert an element "_e" at the head of the list "_l"
  60 */
  61 #define JS_INSERT_LINK(_e,_l) JS_INSERT_AFTER(_e,_l)
  62
  63 /* Return the head/tail of the list */
  64 #define JS_LIST_HEAD(_l) (_l)->next
  65 #define JS_LIST_TAIL(_l) (_l)->prev
  66
  67 /*
  68 ** Remove the element "_e" from it's circular list.
  69 */
  70 #define JS_REMOVE_LINK(_e)             \
  71     JS_BEGIN_MACRO                     \
  72         (_e)->prev->next = (_e)->next; \
  73         (_e)->next->prev = (_e)->prev; \
  74     JS_END_MACRO
  75
  76 /*
  77 ** Remove the element "_e" from it's circular list. Also initializes the
  78 ** linkage.
  79 */
  80 #define JS_REMOVE_AND_INIT_LINK(_e)    \
  81     JS_BEGIN_MACRO                     \
  82         (_e)->prev->next = (_e)->next; \
  83         (_e)->next->prev = (_e)->prev; \
  84         (_e)->next = (_e);             \
  85         (_e)->prev = (_e);             \
  86     JS_END_MACRO
  87
  88 /*
  89 ** Return non-zero if the given circular list "_l" is empty, zero if the
  90 ** circular list is not empty
  91 */
  92 #define JS_CLIST_IS_EMPTY(_l) \
  93     bool((_l)->next == (_l))
  94
  95 /*
  96 ** Initialize a circular list
  97 */
  98 #define JS_INIT_CLIST(_l)  \
  99     JS_BEGIN_MACRO         \
 100         (_l)->next = (_l); \
 101         (_l)->prev = (_l); \
 102     JS_END_MACRO
 103
 104 #define JS_INIT_STATIC_CLIST(_l) \
 105     {(_l), (_l)}
 106
 107 #endif /* jsclist_h */