diff options
Diffstat (limited to 'libavutil/tree.h')
| -rw-r--r-- | libavutil/tree.h | 31 |
1 files changed, 21 insertions, 10 deletions
diff --git a/libavutil/tree.h b/libavutil/tree.h index e2f191cdd7..d5e0aebfbd 100644 --- a/libavutil/tree.h +++ b/libavutil/tree.h @@ -1,20 +1,20 @@ /* * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> * - * This file is part of Libav. + * This file is part of FFmpeg. * - * Libav is free software; you can redistribute it and/or + * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * - * Libav is distributed in the hope that it will be useful, + * FFmpeg 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public - * License along with Libav; if not, write to the Free Software + * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ @@ -43,6 +43,7 @@ struct AVTreeNode; +extern const int av_tree_node_size; /** * Allocate an AVTreeNode. @@ -55,26 +56,34 @@ struct AVTreeNode *av_tree_node_alloc(void); * @param next If next is not NULL, then next[0] will contain the previous * element and next[1] the next element. If either does not exist, * then the corresponding entry in next is unchanged. + * @param cmp compare function used to compare elements in the tree, + * API identical to that of Standard C's qsort + * It is guaranteed that the first and only the first argument to cmp() + * will be the key parameter to av_tree_find(), thus it could if the + * user wants, be a different type (like an opaque context). * @return An element with cmp(key, elem) == 0 or NULL if no such element * exists in the tree. */ void *av_tree_find(const struct AVTreeNode *root, void *key, - int (*cmp)(void *key, const void *b), void *next[2]); + int (*cmp)(const void *key, const void *b), void *next[2]); /** * Insert or remove an element. + * * If *next is NULL, then the supplied element will be removed if it exists. - * If *next is not NULL, then the supplied element will be inserted, unless + * If *next is non-NULL, then the supplied element will be inserted, unless * it already exists in the tree. + * * @param rootp A pointer to a pointer to the root node of the tree; note that * the root node can change during insertions, this is required * to keep the tree balanced. + * @param key pointer to the element key to insert in the tree * @param next Used to allocate and free AVTreeNodes. For insertion the user * must set it to an allocated and zeroed object of at least * av_tree_node_size bytes size. av_tree_insert() will set it to * NULL if it has been consumed. * For deleting elements *next is set to NULL by the user and - * av_tree_node_size() will set it to the AVTreeNode which was + * av_tree_insert() will set it to the AVTreeNode which was * used for the removed element. * This allows the use of flat arrays, which have * lower overhead compared to many malloced elements. @@ -95,13 +104,15 @@ void *av_tree_find(const struct AVTreeNode *root, void *key, * return av_tree_insert(rootp, key, cmp, next); * } * @endcode + * @param cmp compare function used to compare elements in the tree, API identical + * to that of Standard C's qsort * @return If no insertion happened, the found element; if an insertion or * removal happened, then either key or NULL will be returned. * Which one it is depends on the tree state and the implementation. You * should make no assumptions that it's one or the other in the code. */ void *av_tree_insert(struct AVTreeNode **rootp, void *key, - int (*cmp)(void *key, const void *b), + int (*cmp)(const void *key, const void *b), struct AVTreeNode **next); void av_tree_destroy(struct AVTreeNode *t); @@ -109,8 +120,8 @@ void av_tree_destroy(struct AVTreeNode *t); /** * Apply enu(opaque, &elem) to all the elements in the tree in a given range. * - * @param cmp a comparison function that returns < 0 for a element below the - * range, > 0 for a element above the range and == 0 for a + * @param cmp a comparison function that returns < 0 for an element below the + * range, > 0 for an element above the range and == 0 for an * element inside the range * * @note The cmp function should use the same ordering used to construct the |