1 /* Ordered set data type implemented by an array.
2 Copyright (C) 2006-2007, 2009-2011 Free Software Foundation, Inc.
3 Written by Bruno Haible <bruno@clisp.org>, 2006.
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "gl_array_oset.h"
25 /* Checked size_t computations. */
28 /* -------------------------- gl_oset_t Data Type -------------------------- */
30 /* Concrete gl_oset_impl type, valid for this file only. */
33 struct gl_oset_impl_base base;
34 /* An array of ALLOCATED elements, of which the first COUNT are used.
35 0 <= COUNT <= ALLOCATED. */
36 const void **elements;
42 gl_array_nx_create_empty (gl_oset_implementation_t implementation,
43 gl_setelement_compar_fn compar_fn,
44 gl_setelement_dispose_fn dispose_fn)
46 struct gl_oset_impl *set =
47 (struct gl_oset_impl *) malloc (sizeof (struct gl_oset_impl));
52 set->base.vtable = implementation;
53 set->base.compar_fn = compar_fn;
54 set->base.dispose_fn = dispose_fn;
63 gl_array_size (gl_oset_t set)
69 gl_array_indexof (gl_oset_t set, const void *elt)
71 size_t count = set->count;
75 gl_setelement_compar_fn compar = set->base.compar_fn;
79 /* At each loop iteration, low < high; for indices < low the values
80 are smaller than ELT; for indices >= high the values are greater
81 than ELT. So, if the element occurs in the list, it is at
82 low <= position < high. */
85 size_t mid = low + (high - low) / 2; /* low <= mid < high */
86 int cmp = (compar != NULL
87 ? compar (set->elements[mid], elt)
88 : (set->elements[mid] > elt ? 1 :
89 set->elements[mid] < elt ? -1 : 0));
96 /* We have an element equal to ELT at index MID. */
105 gl_array_search (gl_oset_t set, const void *elt)
107 return gl_array_indexof (set, elt) != (size_t)(-1);
111 gl_array_search_atleast (gl_oset_t set,
112 gl_setelement_threshold_fn threshold_fn,
113 const void *threshold,
116 size_t count = set->count;
123 /* At each loop iteration, low < high; for indices < low the values are
124 smaller than THRESHOLD; for indices >= high the values are nonexistent.
125 So, if an element >= THRESHOLD occurs in the list, it is at
126 low <= position < high. */
129 size_t mid = low + (high - low) / 2; /* low <= mid < high */
131 if (! threshold_fn (set->elements[mid], threshold))
135 /* We have an element >= THRESHOLD at index MID. But we need the
136 minimal such index. */
138 /* At each loop iteration, low <= high and
139 compar (list->elements[high], value) >= 0,
140 and we know that the first occurrence of the element is at
141 low <= position <= high. */
144 size_t mid2 = low + (high - low) / 2; /* low <= mid2 < high */
146 if (! threshold_fn (set->elements[mid2], threshold))
151 *eltp = set->elements[low];
160 /* Ensure that set->allocated > set->count.
161 Return 0 upon success, -1 upon out-of-memory. */
165 size_t new_allocated;
169 new_allocated = xtimes (set->allocated, 2);
170 new_allocated = xsum (new_allocated, 1);
171 memory_size = xtimes (new_allocated, sizeof (const void *));
172 if (size_overflow_p (memory_size))
173 /* Overflow, would lead to out of memory. */
175 memory = (const void **) realloc (set->elements, memory_size);
179 set->elements = memory;
180 set->allocated = new_allocated;
184 /* Add the given element ELT at the given position,
185 0 <= position <= gl_oset_size (set).
186 Return 1 upon success, -1 upon out-of-memory. */
188 gl_array_nx_add_at (gl_oset_t set, size_t position, const void *elt)
190 size_t count = set->count;
191 const void **elements;
194 if (count == set->allocated)
197 elements = set->elements;
198 for (i = count; i > position; i--)
199 elements[i] = elements[i - 1];
200 elements[position] = elt;
201 set->count = count + 1;
205 /* Remove the element at the given position,
206 0 <= position < gl_oset_size (set). */
208 gl_array_remove_at (gl_oset_t set, size_t position)
210 size_t count = set->count;
211 const void **elements;
214 elements = set->elements;
215 if (set->base.dispose_fn != NULL)
216 set->base.dispose_fn (elements[position]);
217 for (i = position + 1; i < count; i++)
218 elements[i - 1] = elements[i];
219 set->count = count - 1;
223 gl_array_nx_add (gl_oset_t set, const void *elt)
225 size_t count = set->count;
230 gl_setelement_compar_fn compar = set->base.compar_fn;
233 /* At each loop iteration, low < high; for indices < low the values
234 are smaller than ELT; for indices >= high the values are greater
235 than ELT. So, if the element occurs in the list, it is at
236 low <= position < high. */
239 size_t mid = low + (high - low) / 2; /* low <= mid < high */
240 int cmp = (compar != NULL
241 ? compar (set->elements[mid], elt)
242 : (set->elements[mid] > elt ? 1 :
243 set->elements[mid] < elt ? -1 : 0));
254 return gl_array_nx_add_at (set, low, elt);
258 gl_array_remove (gl_oset_t set, const void *elt)
260 size_t index = gl_array_indexof (set, elt);
261 if (index != (size_t)(-1))
263 gl_array_remove_at (set, index);
271 gl_array_free (gl_oset_t set)
273 if (set->elements != NULL)
275 if (set->base.dispose_fn != NULL)
277 size_t count = set->count;
281 gl_setelement_dispose_fn dispose = set->base.dispose_fn;
282 const void **elements = set->elements;
285 dispose (*elements++);
289 free (set->elements);
294 /* --------------------- gl_oset_iterator_t Data Type --------------------- */
296 static gl_oset_iterator_t
297 gl_array_iterator (gl_oset_t set)
299 gl_oset_iterator_t result;
301 result.vtable = set->base.vtable;
303 result.count = set->count;
304 result.p = set->elements + 0;
305 result.q = set->elements + set->count;
315 gl_array_iterator_next (gl_oset_iterator_t *iterator, const void **eltp)
317 gl_oset_t set = iterator->set;
318 if (iterator->count != set->count)
320 if (iterator->count != set->count + 1)
321 /* Concurrent modifications were done on the set. */
323 /* The last returned element was removed. */
325 iterator->p = (const void **) iterator->p - 1;
326 iterator->q = (const void **) iterator->q - 1;
328 if (iterator->p < iterator->q)
330 const void **p = (const void **) iterator->p;
340 gl_array_iterator_free (gl_oset_iterator_t *iterator)
345 const struct gl_oset_implementation gl_array_oset_implementation =
347 gl_array_nx_create_empty,
350 gl_array_search_atleast,
355 gl_array_iterator_next,
356 gl_array_iterator_free