summaryrefslogtreecommitdiff
path: root/lib/libalpm/alpm_list.c
blob: 0737fc89ff3da3b3b4347c0ed4c4fd7a859384c0 (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
/*
 *  alpm_list.c
 * 
 *  Copyright (c) 2002-2006 by Judd Vinet <jvinet@zeroflux.org>
 * 
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, 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.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 
 *  USA.
 */

#include "config.h"
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>

#include "alpm_list.h"
#include "util.h"

/** \defgroup alpm_list functions */
/*\@{*/

/* Allocation */

/** Allocate a new alpm_list_t
 *  @return a new alpm_list_t item, or NULL on failure
 */
alpm_list_t *alpm_list_new()
{
  alpm_list_t *list = NULL;

  list = (alpm_list_t *)malloc(sizeof(alpm_list_t));
  if(list) {
    list->data = NULL;
    list->prev = NULL;
    list->next = NULL;
  }
  return(list);
}

/** Free a list, but not the contained data
 *  @param list the list to free
 */
void SYMEXPORT alpm_list_free(alpm_list_t *list)
{
  alpm_list_t *it = list;

  while(it) {
    alpm_list_t *tmp = it->next;
    free(it);
    it = tmp;
  }
}

/** Free the internal data of a list structure
 *  @param list the list to free
 *  @param fn a free function for the internal data
 */
void SYMEXPORT alpm_list_free_inner(alpm_list_t *list, alpm_list_fn_free fn)
{
  alpm_list_t *it = list;

  while(it) {
    if(fn && it->data) {
      fn(it->data);
    }
    it = it->next;
  }
}


/* Mutators */

/** Add a new item to the list
 *  @param list the list to add to
 *  @param data the new item to be added to the list
 *  @return the resultant list, or NULL on failure
 */
alpm_list_t SYMEXPORT *alpm_list_add(alpm_list_t *list, void *data)
{
  alpm_list_t *ptr, *lp;

  ptr = list;
  if(ptr == NULL) {
    ptr = alpm_list_new();
    if(ptr == NULL) {
      return(NULL);
    }
  }

  lp = alpm_list_last(ptr);
  if(lp == ptr && lp->data == NULL) {
    /* nada */
  } else {
    lp->next = alpm_list_new();
    if(lp->next == NULL) {
      return(NULL);
    }
    lp->next->prev = lp;
    lp = lp->next;
  }

  lp->data = data;

  return(ptr);
}

/** Add items to a list in sorted order.
 *  @param list the list to add to
 *  @param data the new item to be added to the list
 *  @param fn the comparison function to use to determine order
 *  @return the resultant list, or NULL on failure
 */
alpm_list_t *alpm_list_add_sorted(alpm_list_t *list, void *data, alpm_list_fn_cmp fn)
{
  if(!fn) {
    return alpm_list_add(list, data);
  } else {
    alpm_list_t *add = NULL, *prev = NULL, *next = list;

    add = alpm_list_new();
    add->data = data;

    /* Find insertion point. */
    while(next) {
      if(fn(add->data, next->data) <= 0break;
      prev = next;
      next = next->next;
    }

    /*  Insert node before insertion point. */
    add->prev = prev;
    add->next = next;

    if(next != NULL) {
      next->prev = add;   /*  Not at end.  */
    }

    if(prev != NULL) {
      prev->next = add;       /*  In middle.  */
    } else {
      list = add; /* At beginning, or new list */
    }
    
    return(list);
  }
}

/** Merge the two sorted sublists into one sorted list
 * @param left the first list
 * @param right the second list
 * @param fn comparison function for determining merge order
 */
alpm_list_t *alpm_list_mmerge(alpm_list_t *left, alpm_list_t *right, alpm_list_fn_cmp fn)
{
  alpm_list_t *newlist, *lp;

  if (left == NULL) 
    return right;
  if (right == NULL)
    return left;

  if (fn(left->data, right->data) <= 0) {
    newlist = left;
    left = left->next;
  }
  else {
    newlist = right;
    right = right->next;
  }
  newlist->prev = NULL;
  newlist->next = NULL;
  lp = newlist;

  while ((left != NULL) && (right != NULL)) {
    if (fn(left->data, right->data) <= 0) {
      lp->next = left;
      left->prev = lp;
      left = left->next;
    } 
    else {
      lp->next = right;
      right->prev = lp;
      right = right->next;
    }
    lp = lp->next;
    lp->next = NULL;
  }
  if (left != NULL) {
    lp->next = left;
    left->prev = lp;
  }
  else if (right != NULL) {
    lp->next = right;
    right->prev = lp;
  }
  return(newlist);
}

/** Sort a list of size `n` using mergesort algorithm
 *  @param list the list to sort
 *  @param n the size of the list
 *  @param fn the comparison function for determining order
 */
alpm_list_t* alpm_list_msort(alpm_list_t *list, int n, alpm_list_fn_cmp fn)
{
  if (n > 1) {
    alpm_list_t *left = list;
    alpm_list_t *lastleft = alpm_list_nth(list, n/2 - 1);
    alpm_list_t *right = lastleft->next;
    /* terminate first list */
    lastleft->next = NULL;  

    left = alpm_list_msort(left, n/2, fn);
    right = alpm_list_msort(right, n - (n/2), fn);
    list = alpm_list_mmerge(left, right, fn);
  }
  return(list);
}

/** Remove an item from the list
 *  @param haystack the list to remove the item from
 *  @param needle the data member of the item we're removing
 *  @param fn the comparison function for searching
 *  @param data output parameter containing the data member of the item removed
 *  @return the resultant list, or NULL on failure
 */
alpm_list_t *alpm_list_remove(alpm_list_t *haystack, const void *needle, alpm_list_fn_cmp fn, void **data)
{ /* TODO I modified this to remove ALL matching items.  Do we need a remove_first? */
  alpm_list_t *i = haystack, *tmp = NULL;

  if(data) {
    *data = NULL;
  }

  while(i) {
    if(i->data == NULL) {
      continue;
    }
    tmp = i->next;
    if(fn(needle, i->data) == 0) {
      /* we found a matching item */
      if(i->next) {
        i->next->prev = i->prev;
      }
      if(i->prev) {
        i->prev->next = i->next;
      }

      if(i == haystack) {
        /* The item found is the first in the chain */
        haystack = haystack->next;
      }

      if(data) {
        *data = i->data;
      }
      i->data = NULL;
      free(i);
    }
    i = tmp;
  }

  return(haystack);
}

/** Remove the passed in node from the list that it is a part of
 *  @note this DOES NOT free the node
 *  @param node the list node we're removing
 *  @return the node which took the place of this one
 */
alpm_list_t *alpm_list_remove_node(alpm_list_t *node)
{
  if(!node) return(NULL);

  alpm_list_t *ret = NULL;

  if(node->prev) {
    node->prev->next = node->next;
    ret = node->prev;
    node->prev = NULL;
  }
  if(node->next) {
    node->next->prev = node->prev;
    ret = node->next;
    node->next = NULL;
  }

  return(ret);
}

/** Create a new list without any duplicates
 *  @note DOES NOT copy data members
 *  @param list the list to copy
 *  @return a NEW list containing non-duplicated items
 */
alpm_list_t SYMEXPORT *alpm_list_remove_dupes(alpm_list_t *list)
{ /* TODO does removing the strdup here cause invalid free's anywhere? */
  alpm_list_t *lp = list, *newlist = NULL;
  while(lp) {
    if(!alpm_list_find(newlist, lp->data)) {
      newlist = alpm_list_add(newlist, lp->data);
    }
    lp = lp->next;
  }
  return(newlist);
}

/** Copy a string list, including data
 *  @note this is gross, assumes string data members
 *  @param list the list to copy
 *  @return a copy of the original list
 */
alpm_list_t *alpm_list_strdup(alpm_list_t *list)
{
  alpm_list_t *lp = list, *newlist = NULL;
  while(lp) {
    newlist = alpm_list_add(newlist, strdup(lp->data));
    lp = lp->next;
  }
  return(newlist);
}

/** Create a new list in reverse order
 *  @param list the list to copy
 *  @return a NEW list in reverse order of the first
 */
alpm_list_t *alpm_list_reverse(alpm_list_t *list)
{ /* TODO any invalid free's from NOT duplicating data here? */
  alpm_list_t *lp, *newlist = NULL;

  lp = alpm_list_last(list);
  while(lp) {
    newlist = alpm_list_add(newlist, lp->data);
    lp = lp->prev;
  }
  return(newlist);
}

/* Accessors */

/** Get the first element of a list.
 * @param list the list
 * @return the first element in the list
 */
alpm_list_t SYMEXPORT *alpm_list_first(alpm_list_t *list)
{
  return(list);
}

/** Return nth element from list (starting with 0)
 *  @param list the list to access
 *  @param n the index of the item to find
 *  @return an alpm_list_t node for index `n`
 */
alpm_list_t *alpm_list_nth(alpm_list_t *list, int n)
{
  alpm_list_t *i = list;
  while(n--) {
    i = i->next;
  }
  return(i);
}

/** Get the next element of a list.
 * @param entry the list entry
 * @return the next element, or NULL when no more elements exist
 */
alpm_list_t SYMEXPORT *alpm_list_next(alpm_list_t *entry)
{
  return(entry->next);
}
/** Get the last item in the list.
 *  @param list the list to operate on
 *  @return the last element in the list
 */
alpm_list_t *alpm_list_last(alpm_list_t *list)
{
  alpm_list_t *i = list;
  while(i && i->next) {
    i = i->next;
  }
  return(i);
}

/** Get the data member of a list entry.
 * @param entry the list entry
 * @return the contained data, or NULL if none
 */
void SYMEXPORT *alpm_list_getdata(const alpm_list_t *entry)
{
  if(entry == NULLreturn(NULL);
  return(entry->data);
}

/* Misc */

/** Count the list items
 *  @param list the list to operate on
 *  @return the number of list items
 */
int SYMEXPORT alpm_list_count(const alpm_list_t *list)
{
  unsigned int i = 0;
  const alpm_list_t *lp = list;
  while(lp) {
    ++i;
    lp = lp->next;
  }
  return(i);
}

/** Is an item in the list
 *  @param needle the data to compare to (== comparison)
 *  @param haystack the list to search
 *  @return 1 if `needle` is found, 0 otherwise
 */
int alpm_list_find(alpm_list_t *haystack, const void *needle)
{
  alpm_list_t *lp = haystack;
  while(lp) {
    if(lp->data == needle) {
      return(1);
    }
    lp = lp->next;
  }
  return(0);
}

/* Test for existence of a string in a alpm_list_t
*/
/** Is a _string_ in the list (optimization of alpm_list_find for strings)
 *  @param needle the string to compare
 *  @param haystack the list to search
 *  @return 1 if `needle` is found, 0 otherwise
 */
int alpm_list_find_str(alpm_list_t *haystack, const char *needle)
{
  alpm_list_t *lp = haystack;
  while(lp) {
    if(lp->data && strcmp((const char *)lp->data, needle) == 0) {
      return(1);
    }
    lp = lp->next;
  }
  return(0);
}

/*
 * Calculate the items in list `lhs` that are not present in list `rhs`
 * @note Entries are not duplicated
 * @param lhs the first list
 * @param rhs the second list
 * @param fn the comparison function
 * @return a list containing all items in lhs not present in rhs
 */
alpm_list_t *alpm_list_diff(alpm_list_t *lhs, alpm_list_t *rhs, alpm_list_fn_cmp fn)
{
  alpm_list_t *i, *j, *ret = NULL;
  for(i = lhs; i; i = i->next) {
    int found = 0;
    for(j = rhs; j; j = j->next) {
      if(fn(i->data, j->data) == 0) {
        found = 1;
        break;
      }
    }
    if(!found) {
      ret = alpm_list_add(ret, i->data);
    }
  }

  return(ret);
}

/** @} */

/* vim: set ts=2 sw=2 noet: */