diff options
Diffstat (limited to 'libavutil/tree.h')
| -rw-r--r-- | libavutil/tree.h | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/libavutil/tree.h b/libavutil/tree.h index 146d35d56e..d801a4e028 100644 --- a/libavutil/tree.h +++ b/libavutil/tree.h @@ -28,6 +28,7 @@ #define FFMPEG_TREE_H struct AVTreeNode; +extern const int av_tree_node_size; /** * Finds an element. @@ -46,13 +47,22 @@ void *av_tree_find(const struct AVTreeNode *root, void *key, int (*cmp)(void *ke * @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 next AVTreeNode used for the inserted element, must be allocated and + * zeroed by the user. And will be set to NULL if used by + * av_tree_insert(). This allows the use of flat arrays, which have + * lower overhead compared to many malloced elements. + * You might want to define a function like: + * void *tree_insert(struct AVTreeNode **rootp, void *key, int (*cmp)(void *key, const void *b), AVTreeNode **next){ + * if(!*next) *next= av_mallocz(av_tree_node_size); + * return av_tree_insert(rootp, key, cmp, next); + * } * * @return If no insertion happened, the found element. * If an insertion 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)); +void *av_tree_insert(struct AVTreeNode **rootp, void *key, int (*cmp)(void *key, const void *b), struct AVTreeNode **next); void av_tree_destroy(struct AVTreeNode *t); #endif /* FFMPEG_TREE_H */ |