1 /* GLIB - Library of useful routines for C programming
2 * Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007
3 * Soeren Sandmann (sandmann@daimi.au.dk)
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library 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 GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 * Boston, MA 02111-1307, USA.
23 #include "gsequence.h"
26 #include "gtestutils.h"
30 * @short_description: scalable lists
32 * The #GSequence data structure has the API of a list, but is
33 * implemented internally with a balanced binary tree. This means that
34 * it is possible to maintain a sorted list of n elements in time O(n
35 * log n). The data contained in each element can be either integer
36 * values, by using of the <link
37 * linkend="glib-Type-Conversion-Macros">Type Conversion Macros</link>,
38 * or simply pointers to any type of data.
40 * A #GSequence is accessed through <firstterm>iterators</firstterm>,
41 * represented by a #GSequenceIter. An iterator represents a position
42 * between two elements of the sequence. For example, the
43 * <firstterm>begin</firstterm> iterator represents the gap immediately
44 * before the first element of the sequence, and the
45 * <firstterm>end</firstterm> iterator represents the gap immediately
46 * after the last element. In an empty sequence, the begin and end
47 * iterators are the same.
49 * Some methods on #GSequence operate on ranges of items. For example
50 * g_sequence_foreach_range() will call a user-specified function on
51 * each element with the given range. The range is delimited by the
52 * gaps represented by the passed-in iterators, so if you pass in the
53 * begin and end iterators, the range in question is the entire
56 * The function g_sequence_get() is used with an iterator to access the
57 * element immediately following the gap that the iterator represents.
58 * The iterator is said to <firstterm>point</firstterm> to that element.
60 * Iterators are stable across most operations on a #GSequence. For
61 * example an iterator pointing to some element of a sequence will
62 * continue to point to that element even after the sequence is sorted.
63 * Even moving an element to another sequence using for example
64 * g_sequence_move_range() will not invalidate the iterators pointing
65 * to it. The only operation that will invalidate an iterator is when
66 * the element it points to is removed from any sequence.
72 * The #GSequenceIter struct is an opaque data type representing an
73 * iterator pointing into a #GSequence.
77 * GSequenceIterCompareFunc:
78 * @a: a #GSequenceIter
79 * @b: a #GSequenceIter
81 * @Returns: zero if the iterators are equal, a negative value if @a
82 * comes before @b, and a positive value if @b comes before
85 * A #GSequenceIterCompareFunc is a function used to compare iterators.
86 * It must return zero if the iterators compare equal, a negative value
87 * if @a comes before @b, and a positive value if @b comes before @a.
90 typedef struct _GSequenceNode GSequenceNode;
95 * The #GSequence struct is an opaque data type representing a
96 * <link linkend="glib-Sequences">Sequence</link> data type.
100 GSequenceNode * end_node;
101 GDestroyNotify data_destroy_notify;
102 gboolean access_prohibited;
104 /* The 'real_sequence' is used when temporary sequences are created
105 * to hold nodes that are being rearranged. The 'real_sequence' of such
106 * a temporary sequence points to the sequence that is actually being
107 * manipulated. The only reason we need this is so that when the
108 * sort/sort_changed/search_iter() functions call out to the application
109 * g_sequence_iter_get_sequence() will return the correct sequence.
111 GSequence * real_sequence;
114 struct _GSequenceNode
117 GSequenceNode * parent;
118 GSequenceNode * left;
119 GSequenceNode * right;
120 gpointer data; /* For the end node, this field points
126 * Declaration of GSequenceNode methods
128 static GSequenceNode *node_new (gpointer data);
129 static GSequenceNode *node_get_first (GSequenceNode *node);
130 static GSequenceNode *node_get_last (GSequenceNode *node);
131 static GSequenceNode *node_get_prev (GSequenceNode *node);
132 static GSequenceNode *node_get_next (GSequenceNode *node);
133 static gint node_get_pos (GSequenceNode *node);
134 static GSequenceNode *node_get_by_pos (GSequenceNode *node,
136 static GSequenceNode *node_find (GSequenceNode *haystack,
137 GSequenceNode *needle,
139 GSequenceIterCompareFunc cmp,
141 static GSequenceNode *node_find_closest (GSequenceNode *haystack,
142 GSequenceNode *needle,
144 GSequenceIterCompareFunc cmp,
146 static gint node_get_length (GSequenceNode *node);
147 static void node_free (GSequenceNode *node,
149 static void node_cut (GSequenceNode *split);
150 static void node_insert_before (GSequenceNode *node,
152 static void node_unlink (GSequenceNode *node);
153 static void node_join (GSequenceNode *left,
154 GSequenceNode *right);
155 static void node_insert_sorted (GSequenceNode *node,
158 GSequenceIterCompareFunc cmp_func,
163 * Various helper functions
166 check_seq_access (GSequence *seq)
168 if (G_UNLIKELY (seq->access_prohibited))
170 g_warning ("Accessing a sequence while it is "
171 "being sorted or searched is not allowed");
176 get_sequence (GSequenceNode *node)
178 return (GSequence *)node_get_last (node)->data;
182 check_iter_access (GSequenceIter *iter)
184 check_seq_access (get_sequence (iter));
188 is_end (GSequenceIter *iter)
198 if (iter->parent->right != iter)
201 seq = get_sequence (iter);
203 return seq->end_node == iter;
208 GCompareDataFunc cmp_func;
210 GSequenceNode *end_node;
213 /* This function compares two iters using a normal compare
214 * function and user_data passed in in a SortInfo struct
217 iter_compare (GSequenceIter *node1,
218 GSequenceIter *node2,
221 const SortInfo *info = data;
224 if (node1 == info->end_node)
227 if (node2 == info->end_node)
230 retval = info->cmp_func (node1->data, node2->data, info->cmp_data);
241 * @data_destroy: a #GDestroyNotify function, or %NULL
243 * Creates a new GSequence. The @data_destroy function, if non-%NULL will
244 * be called on all items when the sequence is destroyed and on items that
245 * are removed from the sequence.
247 * Return value: a new #GSequence
252 g_sequence_new (GDestroyNotify data_destroy)
254 GSequence *seq = g_new (GSequence, 1);
255 seq->data_destroy_notify = data_destroy;
257 seq->end_node = node_new (seq);
259 seq->access_prohibited = FALSE;
261 seq->real_sequence = seq;
270 * Frees the memory allocated for @seq. If @seq has a data destroy
271 * function associated with it, that function is called on all items in
277 g_sequence_free (GSequence *seq)
279 g_return_if_fail (seq != NULL);
281 check_seq_access (seq);
283 node_free (seq->end_node, seq);
289 * g_sequence_foreach_range:
290 * @begin: a #GSequenceIter
291 * @end: a #GSequenceIter
293 * @user_data: user data passed to @func
295 * Calls @func for each item in the range (@begin, @end) passing
296 * @user_data to the function.
301 g_sequence_foreach_range (GSequenceIter *begin,
309 g_return_if_fail (func != NULL);
310 g_return_if_fail (begin != NULL);
311 g_return_if_fail (end != NULL);
313 seq = get_sequence (begin);
315 seq->access_prohibited = TRUE;
320 GSequenceIter *next = node_get_next (iter);
322 func (iter->data, user_data);
327 seq->access_prohibited = FALSE;
331 * g_sequence_foreach:
333 * @func: the function to call for each item in @seq
334 * @user_data: user data passed to @func
336 * Calls @func for each item in the sequence passing @user_data
342 g_sequence_foreach (GSequence *seq,
346 GSequenceIter *begin, *end;
348 check_seq_access (seq);
350 begin = g_sequence_get_begin_iter (seq);
351 end = g_sequence_get_end_iter (seq);
353 g_sequence_foreach_range (begin, end, func, user_data);
357 * g_sequence_range_get_midpoint:
358 * @begin: a #GSequenceIter
359 * @end: a #GSequenceIter
361 * Finds an iterator somewhere in the range (@begin, @end). This
362 * iterator will be close to the middle of the range, but is not
363 * guaranteed to be <emphasis>exactly</emphasis> in the middle.
365 * The @begin and @end iterators must both point to the same sequence and
366 * @begin must come before or be equal to @end in the sequence.
368 * Return value: A #GSequenceIter pointing somewhere in the
369 * (@begin, @end) range.
374 g_sequence_range_get_midpoint (GSequenceIter *begin,
377 int begin_pos, end_pos, mid_pos;
379 g_return_val_if_fail (begin != NULL, NULL);
380 g_return_val_if_fail (end != NULL, NULL);
381 g_return_val_if_fail (get_sequence (begin) == get_sequence (end), NULL);
383 begin_pos = node_get_pos (begin);
384 end_pos = node_get_pos (end);
386 g_return_val_if_fail (end_pos >= begin_pos, NULL);
388 mid_pos = begin_pos + (end_pos - begin_pos) / 2;
390 return node_get_by_pos (begin, mid_pos);
394 * g_sequence_iter_compare:
395 * @a: a #GSequenceIter
396 * @b: a #GSequenceIter
398 * Returns a negative number if @a comes before @b, 0 if they are equal,
399 * and a positive number if @a comes after @b.
401 * The @a and @b iterators must point into the same sequence.
403 * Return value: A negative number if @a comes before @b, 0 if they are
404 * equal, and a positive number if @a comes after @b.
409 g_sequence_iter_compare (GSequenceIter *a,
414 g_return_val_if_fail (a != NULL, 0);
415 g_return_val_if_fail (b != NULL, 0);
416 g_return_val_if_fail (get_sequence (a) == get_sequence (b), 0);
418 check_iter_access (a);
419 check_iter_access (b);
421 a_pos = node_get_pos (a);
422 b_pos = node_get_pos (b);
426 else if (a_pos > b_pos)
434 * @seq: a #GSequencePointer
435 * @data: the data for the new item
437 * Adds a new item to the end of @seq.
439 * Return value: an iterator pointing to the new item
444 g_sequence_append (GSequence *seq,
449 g_return_val_if_fail (seq != NULL, NULL);
451 check_seq_access (seq);
453 node = node_new (data);
454 node_insert_before (seq->end_node, node);
460 * g_sequence_prepend:
462 * @data: the data for the new item
464 * Adds a new item to the front of @seq
466 * Return value: an iterator pointing to the new item
471 g_sequence_prepend (GSequence *seq,
474 GSequenceNode *node, *first;
476 g_return_val_if_fail (seq != NULL, NULL);
478 check_seq_access (seq);
480 node = node_new (data);
481 first = node_get_first (seq->end_node);
483 node_insert_before (first, node);
489 * g_sequence_insert_before:
490 * @iter: a #GSequenceIter
491 * @data: the data for the new item
493 * Inserts a new item just before the item pointed to by @iter.
495 * Return value: an iterator pointing to the new item
500 g_sequence_insert_before (GSequenceIter *iter,
505 g_return_val_if_fail (iter != NULL, NULL);
507 check_iter_access (iter);
509 node = node_new (data);
511 node_insert_before (iter, node);
518 * @iter: a #GSequenceIter
520 * Removes the item pointed to by @iter. It is an error to pass the
521 * end iterator to this function.
523 * If the sequnce has a data destroy function associated with it, this
524 * function is called on the data for the removed item.
529 g_sequence_remove (GSequenceIter *iter)
533 g_return_if_fail (iter != NULL);
534 g_return_if_fail (!is_end (iter));
536 check_iter_access (iter);
538 seq = get_sequence (iter);
541 node_free (iter, seq);
545 * g_sequence_remove_range:
546 * @begin: a #GSequenceIter
547 * @end: a #GSequenceIter
549 * Removes all items in the (@begin, @end) range.
551 * If the sequence has a data destroy function associated with it, this
552 * function is called on the data for the removed items.
557 g_sequence_remove_range (GSequenceIter *begin,
560 g_return_if_fail (get_sequence (begin) == get_sequence (end));
562 check_iter_access (begin);
563 check_iter_access (end);
565 g_sequence_move_range (NULL, begin, end);
569 * g_sequence_move_range:
570 * @dest: a #GSequenceIter
571 * @begin: a #GSequenceIter
572 * @end: a #GSequenceIter
574 * Inserts the (@begin, @end) range at the destination pointed to by ptr.
575 * The @begin and @end iters must point into the same sequence. It is
576 * allowed for @dest to point to a different sequence than the one pointed
577 * into by @begin and @end.
579 * If @dest is NULL, the range indicated by @begin and @end is
580 * removed from the sequence. If @dest iter points to a place within
581 * the (@begin, @end) range, the range does not move.
586 g_sequence_move_range (GSequenceIter *dest,
587 GSequenceIter *begin,
591 GSequenceNode *first;
593 g_return_if_fail (begin != NULL);
594 g_return_if_fail (end != NULL);
596 check_iter_access (begin);
597 check_iter_access (end);
599 check_iter_access (dest);
601 src_seq = get_sequence (begin);
603 g_return_if_fail (src_seq == get_sequence (end));
605 /* Dest points to begin or end? */
606 if (dest == begin || dest == end)
609 /* begin comes after end? */
610 if (g_sequence_iter_compare (begin, end) >= 0)
613 /* dest points somewhere in the (begin, end) range? */
614 if (dest && get_sequence (dest) == src_seq &&
615 g_sequence_iter_compare (dest, begin) > 0 &&
616 g_sequence_iter_compare (dest, end) < 0)
621 src_seq = get_sequence (begin);
623 first = node_get_first (begin);
630 node_join (first, end);
634 first = node_get_first (dest);
638 node_join (begin, dest);
641 node_join (first, begin);
645 node_free (begin, src_seq);
652 * @cmp_func: the #GCompareDataFunc used to sort @seq. This function is
653 * passed two items of @seq and should return 0 if they are equal,
654 * a negative value if the first comes before the second, and a
655 * positive value if the second comes before the first.
656 * @cmp_data: user data passed to @cmp_func
658 * Sorts @seq using @cmp_func.
663 g_sequence_sort (GSequence *seq,
664 GCompareDataFunc cmp_func,
669 info.cmp_func = cmp_func;
670 info.cmp_data = cmp_data;
671 info.end_node = seq->end_node;
673 check_seq_access (seq);
675 g_sequence_sort_iter (seq, iter_compare, &info);
679 * g_sequence_insert_sorted:
681 * @data: the data to insert
682 * @cmp_func: the #GCompareDataFunc used to compare items in the sequence. It
683 * is called with two items of the @seq and @user_data. It should
684 * return 0 if the items are equal, a negative value if the first
685 * item comes before the second, and a positive value if the second
686 * item comes before the first.
687 * @cmp_data: user data passed to @cmp_func.
689 * Inserts @data into @sequence using @func to determine the new position.
690 * The sequence must already be sorted according to @cmp_func; otherwise the
691 * new position of @data is undefined.
693 * Return value: a #GSequenceIter pointing to the new item.
698 g_sequence_insert_sorted (GSequence *seq,
700 GCompareDataFunc cmp_func,
705 g_return_val_if_fail (seq != NULL, NULL);
706 g_return_val_if_fail (cmp_func != NULL, NULL);
708 info.cmp_func = cmp_func;
709 info.cmp_data = cmp_data;
710 info.end_node = seq->end_node;
711 check_seq_access (seq);
713 return g_sequence_insert_sorted_iter (seq, data, iter_compare, &info);
717 * g_sequence_sort_changed:
718 * @iter: A #GSequenceIter
719 * @cmp_func: the #GCompareDataFunc used to compare items in the sequence. It
720 * is called with two items of the @seq and @user_data. It should
721 * return 0 if the items are equal, a negative value if the first
722 * item comes before the second, and a positive value if the second
723 * item comes before the first.
724 * @cmp_data: user data passed to @cmp_func.
726 * Moves the data pointed to a new position as indicated by @cmp_func. This
727 * function should be called for items in a sequence already sorted according
728 * to @cmp_func whenever some aspect of an item changes so that @cmp_func
729 * may return different values for that item.
734 g_sequence_sort_changed (GSequenceIter *iter,
735 GCompareDataFunc cmp_func,
740 g_return_if_fail (!is_end (iter));
742 info.cmp_func = cmp_func;
743 info.cmp_data = cmp_data;
744 info.end_node = get_sequence (iter)->end_node;
745 check_iter_access (iter);
747 g_sequence_sort_changed_iter (iter, iter_compare, &info);
753 * @data: data for the new item
754 * @cmp_func: the function used to compare items in the sequence
755 * @cmp_data: user data passed to @cmp_func.
757 * Returns an iterator pointing to the position where @data would
758 * be inserted according to @cmp_func and @cmp_data.
760 * @cmp_func is called with two items of the @seq and @user_data.
761 * It should return 0 if the items are equal, a negative value if
762 * the first item comes before the second, and a positive value if
763 * the second item comes before the first.
765 * If you are simply searching for an existing element of the sequence,
766 * consider using g_sequence_lookup().
768 * Return value: an #GSequenceIter pointing to the position where @data
769 * would have been inserted according to @cmp_func and @cmp_data.
774 g_sequence_search (GSequence *seq,
776 GCompareDataFunc cmp_func,
781 g_return_val_if_fail (seq != NULL, NULL);
783 info.cmp_func = cmp_func;
784 info.cmp_data = cmp_data;
785 info.end_node = seq->end_node;
786 check_seq_access (seq);
788 return g_sequence_search_iter (seq, data, iter_compare, &info);
794 * @data: data to lookup
795 * @cmp_func: the function used to compare items in the sequence
796 * @cmp_data: user data passed to @cmp_func.
798 * Returns an iterator pointing to the position of the first item found
799 * equal to @data according to @cmp_func and @cmp_data. If more than one
800 * item is equal, it is not guaranteed that it is the first which is
801 * returned. In that case, you can use g_sequence_iter_next() and
802 * g_sequence_iter_prev() to get others.
804 * @cmp_func is called with two items of the @seq and @user_data.
805 * It should return 0 if the items are equal, a negative value if
806 * the first item comes before the second, and a positive value if
807 * the second item comes before the first.
809 * Return value: an #GSequenceIter pointing to the position of the
810 * first item found equal to @data according to @cmp_func and @cmp_data.
815 g_sequence_lookup (GSequence *seq,
817 GCompareDataFunc cmp_func,
822 g_return_val_if_fail (seq != NULL, NULL);
824 info.cmp_func = cmp_func;
825 info.cmp_data = cmp_data;
826 info.end_node = seq->end_node;
827 check_seq_access (seq);
829 return g_sequence_lookup_iter (seq, data, iter_compare, &info);
833 * g_sequence_sort_iter:
835 * @cmp_func: the function used to compare iterators in the sequence
836 * @cmp_data: user data passed to @cmp_func
838 * Like g_sequence_sort(), but uses a #GSequenceIterCompareFunc instead
839 * of a GCompareDataFunc as the compare function
841 * @cmp_func is called with two iterators pointing into @seq. It should
842 * return 0 if the iterators are equal, a negative value if the first
843 * iterator comes before the second, and a positive value if the second
844 * iterator comes before the first.
849 g_sequence_sort_iter (GSequence *seq,
850 GSequenceIterCompareFunc cmp_func,
854 GSequenceNode *begin, *end;
856 g_return_if_fail (seq != NULL);
857 g_return_if_fail (cmp_func != NULL);
859 check_seq_access (seq);
861 begin = g_sequence_get_begin_iter (seq);
862 end = g_sequence_get_end_iter (seq);
864 tmp = g_sequence_new (NULL);
865 tmp->real_sequence = seq;
867 g_sequence_move_range (g_sequence_get_begin_iter (tmp), begin, end);
869 seq->access_prohibited = TRUE;
870 tmp->access_prohibited = TRUE;
872 while (g_sequence_get_length (tmp) > 0)
874 GSequenceNode *node = g_sequence_get_begin_iter (tmp);
876 node_insert_sorted (seq->end_node, node, seq->end_node,
880 tmp->access_prohibited = FALSE;
881 seq->access_prohibited = FALSE;
883 g_sequence_free (tmp);
887 * g_sequence_sort_changed_iter:
888 * @iter: a #GSequenceIter
889 * @iter_cmp: the #GSequenceItercompare used to compare iterators in the
890 * sequence. It is called with two iterators pointing into @seq. It should
891 * return 0 if the iterators are equal, a negative value if the first
892 * iterator comes before the second, and a positive value if the second
893 * iterator comes before the first.
894 * @cmp_data: user data passed to @cmp_func
896 * Like g_sequence_sort_changed(), but uses
897 * a #GSequenceIterCompareFunc instead of a #GCompareDataFunc as
898 * the compare function.
903 g_sequence_sort_changed_iter (GSequenceIter *iter,
904 GSequenceIterCompareFunc iter_cmp,
907 GSequence *seq, *tmp_seq;
908 GSequenceIter *next, *prev;
910 g_return_if_fail (iter != NULL);
911 g_return_if_fail (!is_end (iter));
912 g_return_if_fail (iter_cmp != NULL);
913 check_iter_access (iter);
915 /* If one of the neighbours is equal to iter, then
916 * don't move it. This ensures that sort_changed() is
917 * a stable operation.
920 next = node_get_next (iter);
921 prev = node_get_prev (iter);
923 if (prev != iter && iter_cmp (prev, iter, cmp_data) == 0)
926 if (!is_end (next) && iter_cmp (next, iter, cmp_data) == 0)
929 seq = get_sequence (iter);
931 seq->access_prohibited = TRUE;
933 tmp_seq = g_sequence_new (NULL);
934 tmp_seq->real_sequence = seq;
937 node_insert_before (tmp_seq->end_node, iter);
939 node_insert_sorted (seq->end_node, iter, seq->end_node,
942 g_sequence_free (tmp_seq);
944 seq->access_prohibited = FALSE;
948 * g_sequence_insert_sorted_iter:
950 * @data: data for the new item
951 * @iter_cmp: the #GSequenceItercompare used to compare iterators in the
952 * sequence. It is called with two iterators pointing into @seq. It should
953 * return 0 if the iterators are equal, a negative value if the first
954 * iterator comes before the second, and a positive value if the second
955 * iterator comes before the first.
956 * @cmp_data: user data passed to @cmp_func
958 * Like g_sequence_insert_sorted(), but uses
959 * a #GSequenceIterCompareFunc instead of a #GCompareDataFunc as
960 * the compare function.
962 * Return value: a #GSequenceIter pointing to the new item
967 g_sequence_insert_sorted_iter (GSequence *seq,
969 GSequenceIterCompareFunc iter_cmp,
972 GSequenceNode *new_node;
975 g_return_val_if_fail (seq != NULL, NULL);
976 g_return_val_if_fail (iter_cmp != NULL, NULL);
978 check_seq_access (seq);
980 seq->access_prohibited = TRUE;
982 /* Create a new temporary sequence and put the new node into
983 * that. The reason for this is that the user compare function
984 * will be called with the new node, and if it dereferences,
985 * "is_end" will be called on it. But that will crash if the
986 * node is not actually in a sequence.
988 * node_insert_sorted() makes sure the node is unlinked before
991 * The reason we need the "iter" versions at all is that that
992 * is the only kind of compare functions GtkTreeView can use.
994 tmp_seq = g_sequence_new (NULL);
995 tmp_seq->real_sequence = seq;
997 new_node = g_sequence_append (tmp_seq, data);
999 node_insert_sorted (seq->end_node, new_node,
1000 seq->end_node, iter_cmp, cmp_data);
1002 g_sequence_free (tmp_seq);
1004 seq->access_prohibited = FALSE;
1010 * g_sequence_search_iter:
1011 * @seq: a #GSequence
1012 * @data: data for the new item
1013 * @iter_cmp: the #GSequenceIterCompare function used to compare iterators
1014 * in the sequence. It is called with two iterators pointing into @seq.
1015 * It should return 0 if the iterators are equal, a negative value if the
1016 * first iterator comes before the second, and a positive value if the
1017 * second iterator comes before the first.
1018 * @cmp_data: user data passed to @iter_cmp
1020 * Like g_sequence_search(), but uses
1021 * a #GSequenceIterCompareFunc instead of a #GCompareDataFunc as
1022 * the compare function.
1024 * If you are simply searching for an existing element of the sequence,
1025 * consider using g_sequence_lookup_iter().
1027 * Return value: a #GSequenceIter pointing to the position in @seq
1028 * where @data would have been inserted according to @iter_cmp and @cmp_data.
1033 g_sequence_search_iter (GSequence *seq,
1035 GSequenceIterCompareFunc iter_cmp,
1038 GSequenceNode *node;
1039 GSequenceNode *dummy;
1042 g_return_val_if_fail (seq != NULL, NULL);
1044 check_seq_access (seq);
1046 seq->access_prohibited = TRUE;
1048 tmp_seq = g_sequence_new (NULL);
1049 tmp_seq->real_sequence = seq;
1051 dummy = g_sequence_append (tmp_seq, data);
1053 node = node_find_closest (seq->end_node, dummy,
1054 seq->end_node, iter_cmp, cmp_data);
1056 g_sequence_free (tmp_seq);
1058 seq->access_prohibited = FALSE;
1064 * g_sequence_lookup_iter:
1065 * @seq: a #GSequence
1066 * @data: data to lookup
1067 * @iter_cmp: the #GSequenceIterCompare function used to compare iterators
1068 * in the sequence. It is called with two iterators pointing into @seq.
1069 * It should return 0 if the iterators are equal, a negative value if the
1070 * first iterator comes before the second, and a positive value if the
1071 * second iterator comes before the first.
1072 * @cmp_data: user data passed to @iter_cmp
1074 * Like g_sequence_lookup(), but uses
1075 * a #GSequenceIterCompareFunc instead of a #GCompareDataFunc as
1076 * the compare function.
1078 * Return value: an #GSequenceIter pointing to the position of the first item
1079 * found equal to @data according to @cmp_func and @cmp_data.
1084 g_sequence_lookup_iter (GSequence *seq,
1086 GSequenceIterCompareFunc iter_cmp,
1089 GSequenceNode *node;
1090 GSequenceNode *dummy;
1093 g_return_val_if_fail (seq != NULL, NULL);
1095 check_seq_access (seq);
1097 seq->access_prohibited = TRUE;
1099 tmp_seq = g_sequence_new (NULL);
1100 tmp_seq->real_sequence = seq;
1102 dummy = g_sequence_append (tmp_seq, data);
1104 node = node_find (seq->end_node, dummy,
1105 seq->end_node, iter_cmp, cmp_data);
1107 g_sequence_free (tmp_seq);
1109 seq->access_prohibited = FALSE;
1115 * g_sequence_iter_get_sequence:
1116 * @iter: a #GSequenceIter
1118 * Returns the #GSequence that @iter points into.
1120 * Return value: the #GSequence that @iter points into.
1125 g_sequence_iter_get_sequence (GSequenceIter *iter)
1129 g_return_val_if_fail (iter != NULL, NULL);
1131 seq = get_sequence (iter);
1133 /* For temporary sequences, this points to the sequence that
1134 * is actually being manipulated
1136 return seq->real_sequence;
1141 * @iter: a #GSequenceIter
1143 * Returns the data that @iter points to.
1145 * Return value: the data that @iter points to
1150 g_sequence_get (GSequenceIter *iter)
1152 g_return_val_if_fail (iter != NULL, NULL);
1153 g_return_val_if_fail (!is_end (iter), NULL);
1160 * @iter: a #GSequenceIter
1161 * @data: new data for the item
1163 * Changes the data for the item pointed to by @iter to be @data. If
1164 * the sequence has a data destroy function associated with it, that
1165 * function is called on the existing data that @iter pointed to.
1170 g_sequence_set (GSequenceIter *iter,
1175 g_return_if_fail (iter != NULL);
1176 g_return_if_fail (!is_end (iter));
1178 seq = get_sequence (iter);
1180 /* If @data is identical to iter->data, it is destroyed
1181 * here. This will work right in case of ref-counted objects. Also
1182 * it is similar to what ghashtables do.
1184 * For non-refcounted data it's a little less convenient, but
1185 * code relying on self-setting not destroying would be
1186 * pretty dubious anyway ...
1189 if (seq->data_destroy_notify)
1190 seq->data_destroy_notify (iter->data);
1196 * g_sequence_get_length:
1197 * @seq: a #GSequence
1199 * Returns the length of @seq
1201 * Return value: the length of @seq
1206 g_sequence_get_length (GSequence *seq)
1208 return node_get_length (seq->end_node) - 1;
1212 * g_sequence_get_end_iter:
1213 * @seq: a #GSequence
1215 * Returns the end iterator for @seg
1217 * Return value: the end iterator for @seq
1222 g_sequence_get_end_iter (GSequence *seq)
1224 g_return_val_if_fail (seq != NULL, NULL);
1226 return seq->end_node;
1230 * g_sequence_get_begin_iter:
1231 * @seq: a #GSequence
1233 * Returns the begin iterator for @seq.
1235 * Return value: the begin iterator for @seq.
1240 g_sequence_get_begin_iter (GSequence *seq)
1242 g_return_val_if_fail (seq != NULL, NULL);
1244 return node_get_first (seq->end_node);
1248 clamp_position (GSequence *seq,
1251 gint len = g_sequence_get_length (seq);
1253 if (pos > len || pos < 0)
1260 * if pos > number of items or -1, will return end pointer
1263 * g_sequence_get_iter_at_pos:
1264 * @seq: a #GSequence
1265 * @pos: a position in @seq, or -1 for the end.
1267 * Returns the iterator at position @pos. If @pos is negative or larger
1268 * than the number of items in @seq, the end iterator is returned.
1270 * Return value: The #GSequenceIter at position @pos
1275 g_sequence_get_iter_at_pos (GSequence *seq,
1278 g_return_val_if_fail (seq != NULL, NULL);
1280 pos = clamp_position (seq, pos);
1282 return node_get_by_pos (seq->end_node, pos);
1287 * @src: a #GSequenceIter pointing to the item to move
1288 * @dest: a #GSequenceIter pointing to the position to which
1289 * the item is moved.
1291 * Moves the item pointed to by @src to the position indicated by @dest.
1292 * After calling this function @dest will point to the position immediately
1293 * after @src. It is allowed for @src and @dest to point into different
1299 g_sequence_move (GSequenceIter *src,
1300 GSequenceIter *dest)
1302 g_return_if_fail (src != NULL);
1303 g_return_if_fail (dest != NULL);
1304 g_return_if_fail (!is_end (src));
1310 node_insert_before (dest, src);
1316 * g_sequence_iter_is_end:
1317 * @iter: a #GSequenceIter
1319 * Returns whether @iter is the end iterator
1321 * Return value: Whether @iter is the end iterator.
1326 g_sequence_iter_is_end (GSequenceIter *iter)
1328 g_return_val_if_fail (iter != NULL, FALSE);
1330 return is_end (iter);
1334 * g_sequence_iter_is_begin:
1335 * @iter: a #GSequenceIter
1337 * Returns whether @iter is the begin iterator
1339 * Return value: whether @iter is the begin iterator
1344 g_sequence_iter_is_begin (GSequenceIter *iter)
1346 g_return_val_if_fail (iter != NULL, FALSE);
1348 return (node_get_prev (iter) == iter);
1352 * g_sequence_iter_get_position:
1353 * @iter: a #GSequenceIter
1355 * Returns the position of @iter
1357 * Return value: the position of @iter
1362 g_sequence_iter_get_position (GSequenceIter *iter)
1364 g_return_val_if_fail (iter != NULL, -1);
1366 return node_get_pos (iter);
1370 * g_sequence_iter_next:
1371 * @iter: a #GSequenceIter
1373 * Returns an iterator pointing to the next position after @iter. If
1374 * @iter is the end iterator, the end iterator is returned.
1376 * Return value: a #GSequenceIter pointing to the next position after @iter.
1381 g_sequence_iter_next (GSequenceIter *iter)
1383 g_return_val_if_fail (iter != NULL, NULL);
1385 return node_get_next (iter);
1389 * g_sequence_iter_prev:
1390 * @iter: a #GSequenceIter
1392 * Returns an iterator pointing to the previous position before @iter. If
1393 * @iter is the begin iterator, the begin iterator is returned.
1395 * Return value: a #GSequenceIter pointing to the previous position before
1401 g_sequence_iter_prev (GSequenceIter *iter)
1403 g_return_val_if_fail (iter != NULL, NULL);
1405 return node_get_prev (iter);
1409 * g_sequence_iter_move:
1410 * @iter: a #GSequenceIter
1411 * @delta: A positive or negative number indicating how many positions away
1412 * from @iter the returned #GSequenceIter will be.
1414 * Returns the #GSequenceIter which is @delta positions away from @iter.
1415 * If @iter is closer than -@delta positions to the beginning of the sequence,
1416 * the begin iterator is returned. If @iter is closer than @delta positions
1417 * to the end of the sequence, the end iterator is returned.
1419 * Return value: a #GSequenceIter which is @delta positions away from @iter.
1424 g_sequence_iter_move (GSequenceIter *iter,
1430 g_return_val_if_fail (iter != NULL, NULL);
1432 len = g_sequence_get_length (get_sequence (iter));
1434 new_pos = node_get_pos (iter) + delta;
1438 else if (new_pos > len)
1441 return node_get_by_pos (iter, new_pos);
1446 * @a: a #GSequenceIter
1447 * @b: a #GSequenceIter
1449 * Swaps the items pointed to by @a and @b. It is allowed for @a and @b
1450 * to point into difference sequences.
1455 g_sequence_swap (GSequenceIter *a,
1458 GSequenceNode *leftmost, *rightmost, *rightmost_next;
1461 g_return_if_fail (!g_sequence_iter_is_end (a));
1462 g_return_if_fail (!g_sequence_iter_is_end (b));
1467 a_pos = g_sequence_iter_get_position (a);
1468 b_pos = g_sequence_iter_get_position (b);
1481 rightmost_next = node_get_next (rightmost);
1483 /* The situation is now like this:
1485 * ..., leftmost, ......., rightmost, rightmost_next, ...
1488 g_sequence_move (rightmost, leftmost);
1489 g_sequence_move (leftmost, rightmost_next);
1493 * Implementation of a treap
1498 get_priority (GSequenceNode *node)
1500 guint key = GPOINTER_TO_UINT (node);
1502 /* This hash function is based on one found on Thomas Wang's
1505 * http://www.concentric.net/~Ttwang/tech/inthash.htm
1508 key = (key << 15) - key - 1;
1509 key = key ^ (key >> 12);
1510 key = key + (key << 2);
1511 key = key ^ (key >> 4);
1512 key = key + (key << 3) + (key << 11);
1513 key = key ^ (key >> 16);
1515 /* We rely on 0 being less than all other priorities */
1516 return key? key : 1;
1519 static GSequenceNode *
1520 find_root (GSequenceNode *node)
1522 while (node->parent)
1523 node = node->parent;
1528 static GSequenceNode *
1529 node_new (gpointer data)
1531 GSequenceNode *node = g_slice_new0 (GSequenceNode);
1537 node->parent = NULL;
1542 static GSequenceNode *
1543 node_get_first (GSequenceNode *node)
1545 node = find_root (node);
1553 static GSequenceNode *
1554 node_get_last (GSequenceNode *node)
1556 node = find_root (node);
1564 #define NODE_LEFT_CHILD(n) (((n)->parent) && ((n)->parent->left) == (n))
1565 #define NODE_RIGHT_CHILD(n) (((n)->parent) && ((n)->parent->right) == (n))
1567 static GSequenceNode *
1568 node_get_next (GSequenceNode *node)
1570 GSequenceNode *n = node;
1580 while (NODE_RIGHT_CHILD (n))
1592 static GSequenceNode *
1593 node_get_prev (GSequenceNode *node)
1595 GSequenceNode *n = node;
1605 while (NODE_LEFT_CHILD (n))
1617 #define N_NODES(n) ((n)? (n)->n_nodes : 0)
1620 node_get_pos (GSequenceNode *node)
1625 n_smaller = node->left->n_nodes;
1629 if (NODE_RIGHT_CHILD (node))
1630 n_smaller += N_NODES (node->parent->left) + 1;
1632 node = node->parent;
1638 static GSequenceNode *
1639 node_get_by_pos (GSequenceNode *node,
1644 node = find_root (node);
1646 while ((i = N_NODES (node->left)) != pos)
1662 static GSequenceNode *
1663 node_find (GSequenceNode *haystack,
1664 GSequenceNode *needle,
1666 GSequenceIterCompareFunc iter_cmp,
1671 haystack = find_root (haystack);
1675 /* iter_cmp can't be passed the end node, since the function may
1678 if (haystack == end)
1681 c = iter_cmp (haystack, needle, cmp_data);
1687 haystack = haystack->left;
1689 haystack = haystack->right;
1691 while (haystack != NULL);
1696 static GSequenceNode *
1697 node_find_closest (GSequenceNode *haystack,
1698 GSequenceNode *needle,
1700 GSequenceIterCompareFunc iter_cmp,
1703 GSequenceNode *best;
1706 haystack = find_root (haystack);
1712 /* iter_cmp can't be passed the end node, since the function may
1715 if (haystack == end)
1718 c = iter_cmp (haystack, needle, cmp_data);
1720 /* In the following we don't break even if c == 0. Instead we go on
1721 * searching along the 'bigger' nodes, so that we find the last one
1722 * that is equal to the needle.
1725 haystack = haystack->left;
1727 haystack = haystack->right;
1729 while (haystack != NULL);
1731 /* If the best node is smaller or equal to the data, then move one step
1732 * to the right to make sure the best one is strictly bigger than the data
1734 if (best != end && c <= 0)
1735 best = node_get_next (best);
1741 node_get_length (GSequenceNode *node)
1743 node = find_root (node);
1745 return node->n_nodes;
1749 real_node_free (GSequenceNode *node,
1754 real_node_free (node->left, seq);
1755 real_node_free (node->right, seq);
1757 if (seq && seq->data_destroy_notify && node != seq->end_node)
1758 seq->data_destroy_notify (node->data);
1760 g_slice_free (GSequenceNode, node);
1765 node_free (GSequenceNode *node,
1768 node = find_root (node);
1770 real_node_free (node, seq);
1774 node_update_fields (GSequenceNode *node)
1778 n_nodes += N_NODES (node->left);
1779 n_nodes += N_NODES (node->right);
1781 node->n_nodes = n_nodes;
1785 node_rotate (GSequenceNode *node)
1787 GSequenceNode *tmp, *old;
1789 g_assert (node->parent);
1790 g_assert (node->parent != node);
1792 if (NODE_LEFT_CHILD (node))
1797 node->right = node->parent;
1798 node->parent = node->parent->parent;
1801 if (node->parent->left == node->right)
1802 node->parent->left = node;
1804 node->parent->right = node;
1807 g_assert (node->right);
1809 node->right->parent = node;
1810 node->right->left = tmp;
1812 if (node->right->left)
1813 node->right->left->parent = node->right;
1822 node->left = node->parent;
1823 node->parent = node->parent->parent;
1826 if (node->parent->right == node->left)
1827 node->parent->right = node;
1829 node->parent->left = node;
1832 g_assert (node->left);
1834 node->left->parent = node;
1835 node->left->right = tmp;
1837 if (node->left->right)
1838 node->left->right->parent = node->left;
1843 node_update_fields (old);
1844 node_update_fields (node);
1848 node_update_fields_deep (GSequenceNode *node)
1852 node_update_fields (node);
1854 node_update_fields_deep (node->parent);
1859 rotate_down (GSequenceNode *node,
1864 left = node->left ? get_priority (node->left) : 0;
1865 right = node->right ? get_priority (node->right) : 0;
1867 while (priority < left || priority < right)
1870 node_rotate (node->left);
1872 node_rotate (node->right);
1874 left = node->left ? get_priority (node->left) : 0;
1875 right = node->right ? get_priority (node->right) : 0;
1880 node_cut (GSequenceNode *node)
1882 while (node->parent)
1886 node->left->parent = NULL;
1889 node_update_fields (node);
1891 rotate_down (node, get_priority (node));
1895 node_join (GSequenceNode *left,
1896 GSequenceNode *right)
1898 GSequenceNode *fake = node_new (NULL);
1900 fake->left = find_root (left);
1901 fake->right = find_root (right);
1902 fake->left->parent = fake;
1903 fake->right->parent = fake;
1905 node_update_fields (fake);
1909 node_free (fake, NULL);
1913 node_insert_before (GSequenceNode *node,
1916 new->left = node->left;
1918 new->left->parent = new;
1923 node_update_fields_deep (new);
1925 while (new->parent && get_priority (new) > get_priority (new->parent))
1928 rotate_down (new, get_priority (new));
1932 node_unlink (GSequenceNode *node)
1934 rotate_down (node, 0);
1936 if (NODE_RIGHT_CHILD (node))
1937 node->parent->right = NULL;
1938 else if (NODE_LEFT_CHILD (node))
1939 node->parent->left = NULL;
1942 node_update_fields_deep (node->parent);
1944 node->parent = NULL;
1948 node_insert_sorted (GSequenceNode *node,
1951 GSequenceIterCompareFunc iter_cmp,
1954 GSequenceNode *closest;
1956 closest = node_find_closest (node, new, end, iter_cmp, cmp_data);
1960 node_insert_before (closest, new);