/src/rt/uthash/utlist.h
C Header | 280 lines | 188 code | 20 blank | 72 comment | 80 complexity | 46e17b096ad08131da73e6a2258645de MD5 | raw file
1/* 2Copyright (c) 2007-2009, Troy D. Hanson 3All rights reserved. 4 5Redistribution and use in source and binary forms, with or without 6modification, are permitted provided that the following conditions are met: 7 8 * Redistributions of source code must retain the above copyright 9 notice, this list of conditions and the following disclaimer. 10 11THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS 12IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 13TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 14PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER 15OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 16EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 17PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 18PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 19LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 20NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 21SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 22*/ 23 24#ifndef UTLIST_H 25#define UTLIST_H 26 27#define UTLIST_VERSION 1.0 28 29/* C++ requires extra stringent casting */ 30#if defined __cplusplus 31#define LTYPEOF(x) (typeof(x)) 32#else 33#define LTYPEOF(x) 34#endif 35/* 36 * This file contains macros to manipulate singly and doubly-linked lists. 37 * 38 * 1. LL_ macros: singly-linked lists. 39 * 2. DL_ macros: doubly-linked lists. 40 * 3. CDL_ macros: circular doubly-linked lists. 41 * 42 * To use singly-linked lists, your structure must have a "next" pointer. 43 * To use doubly-linked lists, your structure must "prev" and "next" pointers. 44 * Either way, the pointer to the head of the list must be initialized to NULL. 45 * 46 * ----------------.EXAMPLE ------------------------- 47 * struct item { 48 * int id; 49 * struct item *prev, *next; 50 * } 51 * 52 * struct item *list = NULL: 53 * 54 * int main() { 55 * struct item *item; 56 * ... allocate and populate item ... 57 * DL_APPEND(list, item); 58 * } 59 * -------------------------------------------------- 60 * 61 * For doubly-linked lists, the append and delete macros are O(1) 62 * For singly-linked lists, append and delete are O(n) but prepend is O(1) 63 * The sort macro is O(n log(n)) for all types of single/double/circular lists. 64 */ 65 66/****************************************************************************** 67 * The SORT macros * 68 *****************************************************************************/ 69#define LL_SORT(l,cmp) \ 70 LISTSORT(l,0,0,FIELD_OFFSET(l,next),cmp) 71#define DL_SORT(l,cmp) \ 72 LISTSORT(l,0,FIELD_OFFSET(l,prev),FIELD_OFFSET(l,next),cmp) 73#define CDL_SORT(l,cmp) \ 74 LISTSORT(l,1,FIELD_OFFSET(l,prev),FIELD_OFFSET(l,next),cmp) 75 76/* The macros can't assume or cast to the caller's list element type. So we use 77 * a couple tricks when we need to deal with those element's prev/next pointers. 78 * Basically we use char pointer arithmetic to get those field offsets. */ 79#define FIELD_OFFSET(ptr,field) ((char*)&((ptr)->field) - (char*)(ptr)) 80#define LNEXT(e,no) (*(char**)(((char*)e) + no)) 81#define LPREV(e,po) (*(char**)(((char*)e) + po)) 82/****************************************************************************** 83 * The LISTSORT macro is an adaptation of Simon Tatham's O(n log(n)) mergesort* 84 * Unwieldy variable names used here to avoid shadowing passed-in variables. * 85 *****************************************************************************/ 86#define LISTSORT(list, is_circular, po, no, cmp) \ 87do { \ 88 void *_ls_p, *_ls_q, *_ls_e, *_ls_tail, *_ls_oldhead; \ 89 int _ls_insize, _ls_nmerges, _ls_psize, _ls_qsize, _ls_i, _ls_looping; \ 90 int _ls_is_double = (po==0) ? 0 : 1; \ 91 if (list) { \ 92 _ls_insize = 1; \ 93 _ls_looping = 1; \ 94 while (_ls_looping) { \ 95 _ls_p = list; \ 96 _ls_oldhead = list; \ 97 list = NULL; \ 98 _ls_tail = NULL; \ 99 _ls_nmerges = 0; \ 100 while (_ls_p) { \ 101 _ls_nmerges++; \ 102 _ls_q = _ls_p; \ 103 _ls_psize = 0; \ 104 for (_ls_i = 0; _ls_i < _ls_insize; _ls_i++) { \ 105 _ls_psize++; \ 106 if (is_circular) { \ 107 _ls_q = ((LNEXT(_ls_q,no) == _ls_oldhead) ? NULL : LNEXT(_ls_q,no)); \ 108 } else { \ 109 _ls_q = LNEXT(_ls_q,no); \ 110 } \ 111 if (!_ls_q) break; \ 112 } \ 113 _ls_qsize = _ls_insize; \ 114 while (_ls_psize > 0 || (_ls_qsize > 0 && _ls_q)) { \ 115 if (_ls_psize == 0) { \ 116 _ls_e = _ls_q; _ls_q = LNEXT(_ls_q,no); _ls_qsize--; \ 117 if (is_circular && _ls_q == _ls_oldhead) { _ls_q = NULL; } \ 118 } else if (_ls_qsize == 0 || !_ls_q) { \ 119 _ls_e = _ls_p; _ls_p = LNEXT(_ls_p,no); _ls_psize--; \ 120 if (is_circular && (_ls_p == _ls_oldhead)) { _ls_p = NULL; } \ 121 } else if (cmp(LTYPEOF(list)_ls_p,LTYPEOF(list)_ls_q) <= 0) { \ 122 _ls_e = _ls_p; _ls_p = LNEXT(_ls_p,no); _ls_psize--; \ 123 if (is_circular && (_ls_p == _ls_oldhead)) { _ls_p = NULL; } \ 124 } else { \ 125 _ls_e = _ls_q; _ls_q = LNEXT(_ls_q,no); _ls_qsize--; \ 126 if (is_circular && (_ls_q == _ls_oldhead)) { _ls_q = NULL; } \ 127 } \ 128 if (_ls_tail) { \ 129 LNEXT(_ls_tail,no) = (char*)_ls_e; \ 130 } else { \ 131 list = LTYPEOF(list)_ls_e; \ 132 } \ 133 if (_ls_is_double) { \ 134 LPREV(_ls_e,po) = (char*)_ls_tail; \ 135 } \ 136 _ls_tail = _ls_e; \ 137 } \ 138 _ls_p = _ls_q; \ 139 } \ 140 if (is_circular) { \ 141 LNEXT(_ls_tail,no) = (char*)list; \ 142 if (_ls_is_double) { \ 143 LPREV(list,po) = (char*)_ls_tail; \ 144 } \ 145 } else { \ 146 LNEXT(_ls_tail,no) = NULL; \ 147 } \ 148 if (_ls_nmerges <= 1) { \ 149 _ls_looping=0; \ 150 } \ 151 _ls_insize *= 2; \ 152 } \ 153 } \ 154} while (0) 155 156/****************************************************************************** 157 * singly linked list macros (non-circular) * 158 *****************************************************************************/ 159#define LL_PREPEND(head,add) \ 160do { \ 161 (add)->next = head; \ 162 head = add; \ 163} while (0) 164 165#define LL_APPEND(head,add) \ 166do { \ 167 (add)->next=NULL; \ 168 if (head) { \ 169 char *_lla_el = (char*)(head); \ 170 unsigned _lla_no = FIELD_OFFSET(head,next); \ 171 while (LNEXT(_lla_el,_lla_no)) { _lla_el = LNEXT(_lla_el,_lla_no); } \ 172 LNEXT(_lla_el,_lla_no)=(char*)(add); \ 173 } else { \ 174 (head)=(add); \ 175 } \ 176} while (0) 177 178#define LL_DELETE(head,del) \ 179do { \ 180 if ((head) == (del)) { \ 181 (head)=(head)->next; \ 182 } else { \ 183 char *_lld_el = (char*)(head); \ 184 unsigned _lld_no = FIELD_OFFSET(head,next); \ 185 while (LNEXT(_lld_el,_lld_no) && (LNEXT(_lld_el,_lld_no) != (char*)(del))) { \ 186 _lld_el = LNEXT(_lld_el,_lld_no); \ 187 } \ 188 if (LNEXT(_lld_el,_lld_no)) { \ 189 LNEXT(_lld_el,_lld_no) = (char*)((del)->next); \ 190 } \ 191 } \ 192} while (0) 193 194#define LL_FOREACH(head,el) \ 195 for(el=head;el;el=el->next) 196 197/****************************************************************************** 198 * doubly linked list macros (non-circular) * 199 *****************************************************************************/ 200#define DL_PREPEND(head,add) \ 201do { \ 202 (add)->next = head; \ 203 if (head) { \ 204 (add)->prev = (head)->prev; \ 205 (head)->prev = (add); \ 206 } else { \ 207 (add)->prev = (add); \ 208 } \ 209 (head) = (add); \ 210} while (0) 211 212#define DL_APPEND(head,add) \ 213do { \ 214 if (head) { \ 215 (add)->prev = (head)->prev; \ 216 (head)->prev->next = (add); \ 217 (head)->prev = (add); \ 218 (add)->next = NULL; \ 219 } else { \ 220 (head)=(add); \ 221 (head)->prev = (head); \ 222 (head)->next = NULL; \ 223 } \ 224} while (0); 225 226#define DL_DELETE(head,del) \ 227do { \ 228 if ((del)->prev == (del)) { \ 229 (head)=NULL; \ 230 } else if ((del)==(head)) { \ 231 (del)->next->prev = (del)->prev; \ 232 (head) = (del)->next; \ 233 } else { \ 234 (del)->prev->next = (del)->next; \ 235 if ((del)->next) { \ 236 (del)->next->prev = (del)->prev; \ 237 } else { \ 238 (head)->prev = (del)->prev; \ 239 } \ 240 } \ 241} while (0); 242 243 244#define DL_FOREACH(head,el) \ 245 for(el=head;el;el=el->next) 246 247/****************************************************************************** 248 * circular doubly linked list macros * 249 *****************************************************************************/ 250#define CDL_PREPEND(head,add) \ 251do { \ 252 if (head) { \ 253 (add)->prev = (head)->prev; \ 254 (add)->next = (head); \ 255 (head)->prev = (add); \ 256 (add)->prev->next = (add); \ 257 } else { \ 258 (add)->prev = (add); \ 259 (add)->next = (add); \ 260 } \ 261(head)=(add); \ 262} while (0) 263 264#define CDL_DELETE(head,del) \ 265do { \ 266 if ( ((head)==(del)) && ((head)->next == (head))) { \ 267 (head) = 0L; \ 268 } else { \ 269 (del)->next->prev = (del)->prev; \ 270 (del)->prev->next = (del)->next; \ 271 if ((del) == (head)) (head)=(del)->next; \ 272 } \ 273} while (0); 274 275#define CDL_FOREACH(head,el) \ 276 for(el=head;el;el= (el->next==head ? 0L : el->next)) 277 278 279#endif /* UTLIST_H */ 280