src/LinkedList.cc

   1 // LinkedList.cc for Blackbox - an X11 Window manager
   2 // Copyright (c) 1997 - 2000 Brad Hughes (bhughes@tcac.net)
   3 //
   4 // Permission is hereby granted, free of charge, to any person obtaining a
   5 // copy of this software and associated documentation files (the "Software"),
   6 // to deal in the Software without restriction, including without limitation
   7 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8 // and/or sell copies of the Software, and to permit persons to whom the
   9 // Software is furnished to do so, subject to the following conditions:
  10 //
  11 // The above copyright notice and this permission notice shall be included in
  12 // all copies or substantial portions of the Software.
  13 //
  14 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17 // THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  19 // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  20 // DEALINGS IN THE SOFTWARE.
  21 //
  22 // $Id$
  23
  24 // stupid macros needed to access some functions in version 2 of the GNU C
  25 // library
  26 #ifndef   _GNU_SOURCE
  27 #define   _GNU_SOURCE
  28 #endif // _GNU_SOURCE
  29
  30 #include "LinkedList.hh"
  31
  32 #ifdef    HAVE_CONFIG_H
  33 #  include "../config.h"
  34 #endif // HAVE_CONFIG_H
  35
  36 #ifdef    HAVE_STDIO_H
  37 #  include <stdio.h>
  38 #endif // HAVE_STDIO_H
  39
  40
  41 __llist_iterator::__llist_iterator(__llist *l) {
  42   // initialize the iterator...
  43   list = l;
  44
  45   if (list) {
  46     if (! list->iterators)
  47       list->iterators = new __llist;
  48
  49     list->iterators->insert(this);
  50   }
  51
  52   reset();
  53 }
  54
  55
  56 __llist_iterator::~__llist_iterator(void) {
  57   if (list && list->iterators)
  58     list->iterators->remove(this);
  59 }
  60
  61
  62 void *__llist_iterator::current(void) {
  63   // return the current node data... if any
  64   return ((node) ? node->getData() : 0);
  65 }
  66
  67
  68 void __llist_iterator::reset(void) {
  69   // update the iterator's current node to the first node in the linked list
  70   if (list)
  71     node = list->_first;
  72 }
  73
  74
  75 const int __llist_iterator::set(const int index) {
  76   // set the current node to index
  77   if (list) {
  78     if (index < list->elements && index >= 0 && list->_first) {
  79       node = list->_first;
  80
  81       for (register int i = 0; i < index; i++)
  82         node = node->getNext();
  83
  84       return 1;
  85     }
  86   }
  87
  88   node = (__llist_node *) 0;
  89   return 0;
  90 }
  91
  92
  93 void __llist_iterator::operator++(void) {
  94   // iterate to the next node in the list...
  95   node = ((node) ? node->getNext() : 0);
  96 }
  97
  98
  99 void __llist_iterator::operator++(int) {
 100   // iterate to the next node in the list...
 101   node = ((node) ? node->getNext() : 0);
 102 }
 103
 104
 105 __llist::__llist(void *d) {
 106   // initialize the linked list...
 107   _first = (__llist_node *) 0;
 108   _last = (__llist_node *) 0;
 109   iterators = (__llist *) 0;
 110   elements = 0;
 111
 112   if (d) insert(d);
 113 }
 114
 115
 116 __llist::~__llist(void) {
 117   // remove all the items in the list...
 118   for (register int i = 0, r = elements; i < r; i++)
 119     remove(0);
 120
 121   if (iterators) {
 122     __llist_node *n = iterators->_first;
 123
 124     while (n) {
 125       ((__llist_iterator *) n->getData())->list = (__llist *) 0;
 126       ((__llist_iterator *) n->getData())->node = (__llist_node *) 0;
 127
 128       n = n->getNext();
 129     }
 130
 131     delete iterators;
 132   }
 133 }
 134
 135
 136 const int __llist::insert(void *d, int index) {
 137   // insert item into linked list at specified index...
 138
 139   if ((! _first) || (! _last)) {
 140     // list is empty... insert the item as the first item, regardless of the
 141     // index given
 142     _first = new __llist_node;
 143     _first->setData(d);
 144     _first->setNext((__llist_node *) 0);
 145     _last = _first;
 146   } else {
 147     if (index == 0) {
 148       // if index is 0... prepend the data on the list
 149       __llist_node *nnode = new __llist_node;
 150
 151       nnode->setData(d);
 152       nnode->setNext(_first);
 153
 154       _first = nnode;
 155     } else if ((index == -1) || (index == elements)) {
 156       // if index is -1... append the data on the list
 157       __llist_node *nnode = new __llist_node;
 158
 159       nnode->setData(d);
 160       nnode->setNext((__llist_node *) 0);
 161       _last->setNext(nnode);
 162
 163       _last = nnode;
 164     } else if (index < elements) {
 165       // otherwise... insert the item at the position specified by index
 166       __llist_node *nnode = new __llist_node, *inode = _first;
 167
 168       if (! nnode)
 169         return -1;
 170
 171       nnode->setData(d);
 172
 173       for (register int i = 1; i < index; i++)
 174         if (inode)
 175           inode = inode->getNext();
 176         else {
 177           delete nnode;
 178           return -1;
 179         }
 180
 181       if ((! inode) || inode == _last) {
 182         nnode->setNext((__llist_node *) 0);
 183         _last->setNext(nnode);
 184
 185         _last = nnode;
 186       } else {
 187         nnode->setNext(inode->getNext());
 188         inode->setNext(nnode);
 189       }
 190     }
 191   }
 192
 193   return ++elements;
 194 }
 195
 196
 197 const int __llist::remove(void *d) {
 198   // remove list item whose data pointer address matches the pointer address
 199   // given
 200
 201   if ((! _first) || (! _last))
 202     return -1;
 203   else if (_first->getData() == d) {
 204     // remove the first item in the list...
 205     __llist_node *node = _first;
 206     _first = _first->getNext();
 207
 208     if (iterators && iterators->_first) {
 209       __llist_node *n = iterators->_first;
 210       while (n) {
 211         ((__llist_iterator *) n->getData())->reset();
 212         n = n->getNext();
 213       }
 214     }
 215
 216     --elements;
 217     delete node;
 218     return 0;
 219   } else {
 220     // iterate through the list and remove the first occurance of the item
 221
 222     // NOTE: we don't validate _first in this assignment, because it is checked
 223     // for validity above...
 224     __llist_node *rnode = _first->getNext(), *prev = _first;
 225
 226     for (register int i = 1; i < elements; i++)
 227       if (rnode)
 228         if (rnode->getData() == d) {
 229           // we found the item... update the previous node and delete the
 230           // now useless rnode...
 231           prev->setNext(rnode->getNext());
 232
 233           if (rnode == _last)
 234             _last = prev;
 235
 236           if (iterators && iterators->_first) {
 237             __llist_node *n = iterators->_first;
 238             while (n) {
 239               ((__llist_iterator *) n->getData())->reset();
 240               n = n->getNext();
 241             }
 242           }
 243
 244           --elements;
 245           delete rnode;
 246           return i;
 247         } else {
 248           prev = rnode;
 249           rnode = rnode->getNext();
 250         }
 251
 252     return -1;
 253   }
 254 }
 255
 256
 257 void *__llist::remove(const int index) {
 258   if (index >= elements || index < 0 || (! _first) || (! _last))
 259     return (void *) 0;
 260
 261   // remove list item at specified index within the list
 262   if (index == 0) {
 263     // remove the first item in the list...
 264     __llist_node *node = _first;
 265     void *data_return = _first->getData();
 266
 267     _first = _first->getNext();
 268
 269     if (iterators && iterators->_first) {
 270       __llist_node *n = iterators->_first;
 271       while (n) {
 272         ((__llist_iterator *) n->getData())->reset();
 273         n = n->getNext();
 274       }
 275     }
 276
 277     --elements;
 278     delete node;
 279
 280     return data_return;
 281   } else {
 282     __llist_node *rnode = _first->getNext(), *prev = _first;
 283     void *data_return = (void *) 0;
 284
 285     for (register int i = 1; i < index; i++)
 286       if (rnode) {
 287         prev = rnode;
 288         rnode = rnode->getNext();
 289       } else
 290         return (void *) 0;
 291
 292     if (! rnode) return (void *) 0;
 293
 294     prev->setNext(rnode->getNext());
 295     data_return = rnode->getData();
 296
 297     if (rnode == _last)
 298       _last = prev;
 299
 300     if (iterators && iterators->_first) {
 301       __llist_node *n = iterators->_first;
 302       while (n) {
 303         ((__llist_iterator *) n->getData())->reset();
 304         n = n->getNext();
 305       }
 306     }
 307
 308     --elements;
 309     data_return = rnode->getData();
 310     delete rnode;
 311     return data_return;
 312   }
 313
 314   return (void *) 0;
 315 }
 316
 317
 318 void *__llist::find(const int index) {
 319   if (index >= elements || index < 0 || (! _first) || (! _last))
 320     return (void *) 0;
 321
 322   if (index == 0) {
 323     // return the first item
 324     return first();
 325   } else if (index == (elements - 1)) {
 326     // return the last item
 327     return last();
 328   } else {
 329     __llist_node *fnode = _first->getNext();
 330
 331     for (register int i = 1; i < index; i++)
 332       if (fnode)
 333         fnode = fnode->getNext();
 334       else
 335         return (void *) 0;
 336
 337     return fnode->getData();
 338   }
 339
 340   return (void *) 0;
 341 }
 342
 343
 344 void *__llist::first(void) {
 345   if (_first)
 346     return _first->getData();
 347
 348   return (void *) 0;
 349 }
 350
 351
 352 void *__llist::last(void) {
 353   if (_last)
 354     return _last->getData();
 355
 356   return (void *) 0;
 357 }