aboutsummaryrefslogtreecommitdiffstats
path: root/menuselect/mxml/mxml-index.c
blob: aebb3d8d5d5602617646b5b96f1ad4805ab931cc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
/*
 * "$Id: mxml-index.c 22267 2006-04-24 17:11:45Z kpfleming $"
 *
 * Index support code for Mini-XML, a small XML-like file parsing library.
 *
 * Copyright 2003-2005 by Michael Sweet.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * Contents:
 *
 *   mxmlIndexDelete()   - Delete an index.
 *   mxmlIndexEnum()     - Return the next node in the index.
 *   mxmlIndexFind()     - Find the next matching node.
 *   mxmlIndexNew()      - Create a new index.
 *   mxmlIndexReset()    - Reset the enumeration/find pointer in the index and
 *                         return the first node in the index.
 *   index_compare()     - Compare two nodes.
 *   index_find()        - Compare a node with index values.
 *   index_sort()        - Sort the nodes in the index...
 */

/*
 * Include necessary headers...
 */

#include "config.h"
#include "mxml.h"


/*
 * Sort functions...
 */

static int	index_compare(mxml_index_t *ind, mxml_node_t *first,
		              mxml_node_t *second);
static int	index_find(mxml_index_t *ind, const char *element,
		           const char *value, mxml_node_t *node);
static void	index_sort(mxml_index_t *ind, int left, int right);


/*
 * 'mxmlIndexDelete()' - Delete an index.
 */

void
mxmlIndexDelete(mxml_index_t *ind)	/* I - Index to delete */
{
 /*
  * Range check input..
  */

  if (!ind)
    return;

 /*
  * Free memory...
  */

  if (ind->attr)
    free(ind->attr);

  if (ind->alloc_nodes)
    free(ind->nodes);

  free(ind);
}


/*
 * 'mxmlIndexEnum()' - Return the next node in the index.
 *
 * Nodes are returned in the sorted order of the index.
 */

mxml_node_t *				/* O - Next node or NULL if there is none */
mxmlIndexEnum(mxml_index_t *ind)	/* I - Index to enumerate */
{
 /*
  * Range check input...
  */

  if (!ind)
    return (NULL);

 /*
  * Return the next node...
  */

  if (ind->cur_node < ind->num_nodes)
    return (ind->nodes[ind->cur_node ++]);
  else
    return (NULL);
}


/*
 * 'mxmlIndexFind()' - Find the next matching node.
 *
 * You should call mxmlIndexReset() prior to using this function for
 * the first time with a particular set of "element" and "value"
 * strings. Passing NULL for both "element" and "value" is equivalent
 * to calling mxmlIndexEnum().
 */

mxml_node_t *				/* O - Node or NULL if none found */
mxmlIndexFind(mxml_index_t *ind,	/* I - Index to search */
              const char   *element,	/* I - Element name to find, if any */
	      const char   *value)	/* I - Attribute value, if any */
{
  int		diff,			/* Difference between names */
		current,		/* Current entity in search */
		first,			/* First entity in search */
		last;			/* Last entity in search */


#ifdef DEBUG
  printf("mxmlIndexFind(ind=%p, element=\"%s\", value=\"%s\")\n",
         ind, element ? element : "(null)", value ? value : "(null)");
#endif /* DEBUG */

 /*
  * Range check input...
  */

  if (!ind || (!ind->attr && value))
  {
#ifdef DEBUG
    puts("    returning NULL...");
    printf("    ind->attr=\"%s\"\n", ind->attr ? ind->attr : "(null)");
#endif /* DEBUG */

    return (NULL);
  }

 /*
  * If both element and value are NULL, just enumerate the nodes in the
  * index...
  */

  if (!element && !value)
    return (mxmlIndexEnum(ind));

 /*
  * If there are no nodes in the index, return NULL...
  */

  if (!ind->num_nodes)
  {
#ifdef DEBUG
    puts("    returning NULL...");
    puts("    no nodes!");
#endif /* DEBUG */

    return (NULL);
  }

 /*
  * If cur_node == 0, then find the first matching node...
  */

  if (ind->cur_node == 0)
  {
   /*
    * Find the first node using a modified binary search algorithm...
    */

    first = 0;
    last  = ind->num_nodes - 1;

#ifdef DEBUG
    printf("    find first time, num_nodes=%d...\n", ind->num_nodes);
#endif /* DEBUG */

    while ((last - first) > 1)
    {
      current = (first + last) / 2;

#ifdef DEBUG
      printf("    first=%d, last=%d, current=%d\n", first, last, current);
#endif /* DEBUG */

      if ((diff = index_find(ind, element, value, ind->nodes[current])) == 0)
      {
       /*
        * Found a match, move back to find the first...
	*/

#ifdef DEBUG
        puts("    match!");
#endif /* DEBUG */

        while (current > 0 &&
	       !index_find(ind, element, value, ind->nodes[current - 1]))
	  current --;

#ifdef DEBUG
        printf("    returning first match=%d\n", current);
#endif /* DEBUG */

       /*
        * Return the first match and save the index to the next...
	*/

        ind->cur_node = current + 1;

	return (ind->nodes[current]);
      }
      else if (diff < 0)
	last = current;
      else
	first = current;

#ifdef DEBUG
      printf("    diff=%d\n", diff);
#endif /* DEBUG */
    }

   /*
    * If we get this far, then we found exactly 0 or 1 matches...
    */

    for (current = first; current <= last; current ++)
      if (!index_find(ind, element, value, ind->nodes[current]))
      {
       /*
	* Found exactly one (or possibly two) match...
	*/

#ifdef DEBUG
	printf("    returning only match %d...\n", current);
#endif /* DEBUG */

	ind->cur_node = current + 1;

	return (ind->nodes[current]);
      }

   /*
    * No matches...
    */

    ind->cur_node = ind->num_nodes;

#ifdef DEBUG
    puts("    returning NULL...");
#endif /* DEBUG */

    return (NULL);
  }
  else if (ind->cur_node < ind->num_nodes &&
           !index_find(ind, element, value, ind->nodes[ind->cur_node]))
  {
   /*
    * Return the next matching node...
    */

#ifdef DEBUG
    printf("    returning next match %d...\n", ind->cur_node);
#endif /* DEBUG */

    return (ind->nodes[ind->cur_node ++]);
  }

 /*
  * If we get this far, then we have no matches...
  */

  ind->cur_node = ind->num_nodes;

#ifdef DEBUG
  puts("    returning NULL...");
#endif /* DEBUG */

  return (NULL);
}


/*
 * 'mxmlIndexNew()' - Create a new index.
 *
 * The index will contain all nodes that contain the named element and/or
 * attribute. If both "element" and "attr" are NULL, then the index will
 * contain a sorted list of the elements in the node tree.  Nodes are
 * sorted by element name and optionally by attribute value if the "attr"
 * argument is not NULL.
 */

mxml_index_t *				/* O - New index */
mxmlIndexNew(mxml_node_t *node,		/* I - XML node tree */
             const char  *element,	/* I - Element to index or NULL for all */
             const char  *attr)		/* I - Attribute to index or NULL for none */
{
  mxml_index_t	*ind;			/* New index */
  mxml_node_t	*current,		/* Current node in index */
  		**temp;			/* Temporary node pointer array */


 /*
  * Range check input...
  */

#ifdef DEBUG
  printf("mxmlIndexNew(node=%p, element=\"%s\", attr=\"%s\")\n",
         node, element ? element : "(null)", attr ? attr : "(null)");
#endif /* DEBUG */

  if (!node)
    return (NULL);

 /*
  * Create a new index...
  */

  if ((ind = calloc(1, sizeof(mxml_index_t))) == NULL)
  {
    mxml_error("Unable to allocate %d bytes for index - %s",
               sizeof(mxml_index_t), strerror(errno));
    return (NULL);
  }

  if (attr)
    ind->attr = strdup(attr);

  if (!element && !attr)
    current = node;
  else
    current = mxmlFindElement(node, node, element, attr, NULL, MXML_DESCEND);

  while (current)
  {
    if (ind->num_nodes >= ind->alloc_nodes)
    {
      if (!ind->alloc_nodes)
        temp = malloc(64 * sizeof(mxml_node_t *));
      else
        temp = realloc(ind->nodes, (ind->alloc_nodes + 64) * sizeof(mxml_node_t *));

      if (!temp)
      {
       /*
        * Unable to allocate memory for the index, so abort...
	*/

        mxml_error("Unable to allocate %d bytes for index: %s",
	           (ind->alloc_nodes + 64) * sizeof(mxml_node_t *),
		   strerror(errno));

        mxmlIndexDelete(ind);
	return (NULL);
      }

      ind->nodes       = temp;
      ind->alloc_nodes += 64;
    }

    ind->nodes[ind->num_nodes ++] = current;

    current = mxmlFindElement(current, node, element, attr, NULL, MXML_DESCEND);
  }

 /*
  * Sort nodes based upon the search criteria...
  */

#ifdef DEBUG
  {
    int i;				/* Looping var */


    printf("%d node(s) in index.\n\n", ind->num_nodes);

    if (attr)
    {
      printf("Node      Address   Element         %s\n", attr);
      puts("--------  --------  --------------  ------------------------------");

      for (i = 0; i < ind->num_nodes; i ++)
	printf("%8d  %-8p  %-14.14s  %s\n", i, ind->nodes[i],
	       ind->nodes[i]->value.element.name,
	       mxmlElementGetAttr(ind->nodes[i], attr));
    }
    else
    {
      puts("Node      Address   Element");
      puts("--------  --------  --------------");

      for (i = 0; i < ind->num_nodes; i ++)
	printf("%8d  %-8p  %s\n", i, ind->nodes[i],
	       ind->nodes[i]->value.element.name);
    }

    putchar('\n');
  }
#endif /* DEBUG */

  if (ind->num_nodes > 1)
    index_sort(ind, 0, ind->num_nodes - 1);

#ifdef DEBUG
  {
    int i;				/* Looping var */


    puts("After sorting:\n");

    if (attr)
    {
      printf("Node      Address   Element         %s\n", attr);
      puts("--------  --------  --------------  ------------------------------");

      for (i = 0; i < ind->num_nodes; i ++)
	printf("%8d  %-8p  %-14.14s  %s\n", i, ind->nodes[i],
	       ind->nodes[i]->value.element.name,
	       mxmlElementGetAttr(ind->nodes[i], attr));
    }
    else
    {
      puts("Node      Address   Element");
      puts("--------  --------  --------------");

      for (i = 0; i < ind->num_nodes; i ++)
	printf("%8d  %-8p  %s\n", i, ind->nodes[i],
	       ind->nodes[i]->value.element.name);
    }

    putchar('\n');
  }
#endif /* DEBUG */

 /*
  * Return the new index...
  */

  return (ind);
}


/*
 * 'mxmlIndexReset()' - Reset the enumeration/find pointer in the index and
 *                      return the first node in the index.
 *
 * This function should be called prior to using mxmlIndexEnum() or
 * mxmlIndexFind() for the first time.
 */

mxml_node_t *				/* O - First node or NULL if there is none */
mxmlIndexReset(mxml_index_t *ind)	/* I - Index to reset */
{
#ifdef DEBUG
  printf("mxmlIndexReset(ind=%p)\n", ind);
#endif /* DEBUG */

 /*
  * Range check input...
  */

  if (!ind)
    return (NULL);

 /*
  * Set the index to the first element...
  */

  ind->cur_node = 0;

 /*
  * Return the first node...
  */

  if (ind->num_nodes)
    return (ind->nodes[0]);
  else
    return (NULL);
}


/*
 * 'index_compare()' - Compare two nodes.
 */

static int				/* O - Result of comparison */
index_compare(mxml_index_t *ind,	/* I - Index */
              mxml_node_t  *first,	/* I - First node */
              mxml_node_t  *second)	/* I - Second node */
{
  int	diff;				/* Difference */


 /*
  * Check the element name...
  */

  if ((diff = strcmp(first->value.element.name,
                     second->value.element.name)) != 0)
    return (diff);

 /*
  * Check the attribute value...
  */

  if (ind->attr)
  {
    if ((diff = strcmp(mxmlElementGetAttr(first, ind->attr),
                       mxmlElementGetAttr(second, ind->attr))) != 0)
      return (diff);
  }

 /*
  * No difference, return 0...
  */

  return (0);
}


/*
 * 'index_find()' - Compare a node with index values.
 */

static int				/* O - Result of comparison */
index_find(mxml_index_t *ind,		/* I - Index */
           const char   *element,	/* I - Element name or NULL */
	   const char   *value,		/* I - Attribute value or NULL */
           mxml_node_t  *node)		/* I - Node */
{
  int	diff;				/* Difference */


 /*
  * Check the element name...
  */

  if (element)
  {
    if ((diff = strcmp(element, node->value.element.name)) != 0)
      return (diff);
  }

 /*
  * Check the attribute value...
  */

  if (value)
  {
    if ((diff = strcmp(value, mxmlElementGetAttr(node, ind->attr))) != 0)
      return (diff);
  }

 /*
  * No difference, return 0...
  */

  return (0);
}


/*
 * 'index_sort()' - Sort the nodes in the index...
 *
 * This function implements the classic quicksort algorithm...
 */

static void
index_sort(mxml_index_t *ind,		/* I - Index to sort */
           int          left,		/* I - Left node in partition */
	   int          right)		/* I - Right node in partition */
{
  mxml_node_t	*pivot,			/* Pivot node */
		*temp;			/* Swap node */
  int		templ,			/* Temporary left node */
		tempr;			/* Temporary right node */


 /*
  * Loop until we have sorted all the way to the right...
  */

  do
  {
   /*
    * Sort the pivot in the current partition...
    */

    pivot = ind->nodes[left];

    for (templ = left, tempr = right; templ < tempr;)
    {
     /*
      * Move left while left node <= pivot node...
      */

      while ((templ < right) &&
             index_compare(ind, ind->nodes[templ], pivot) <= 0)
	templ ++;

     /*
      * Move right while right node > pivot node...
      */

      while ((tempr > left) &&
             index_compare(ind, ind->nodes[tempr], pivot) > 0)
	tempr --;

     /*
      * Swap nodes if needed...
      */

      if (templ < tempr)
      {
	temp              = ind->nodes[templ];
	ind->nodes[templ] = ind->nodes[tempr];
	ind->nodes[tempr] = temp;
      }
    }

   /*
    * When we get here, the right (tempr) node is the new position for the
    * pivot node...
    */

    if (index_compare(ind, pivot, ind->nodes[tempr]) > 0)
    {
      ind->nodes[left]  = ind->nodes[tempr];
      ind->nodes[tempr] = pivot;
    }

   /*
    * Recursively sort the left partition as needed...
    */

    if (left < (tempr - 1))
      index_sort(ind, left, tempr - 1);
  }
  while (right > (left = tempr + 1));
}


/*
 * End of "$Id: mxml-index.c 22267 2006-04-24 17:11:45Z kpfleming $".
 */