Functions
Insert or remove an element.
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Apply enu(opaque, &elem) to all the elements in the tree in a given range.
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Variables
Detailed Description
Low-complexity tree container
Insertion, removal, finding equal, largest which is smaller than and smallest which is larger than, all have O(log n) worst-case complexity.
Function Documentation
◆ av_tree_node_alloc()
◆ av_tree_find()
void* av_tree_find
(
const struct
AVTreeNode *
root,
void *
key,
int(*)(const void *
key, const void *
b)
cmp,
void *
next[2]
)
Find an element.
- Parameters
-
root a pointer to the root node of the tree
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.
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).
- Returns
- An element with cmp(key, elem) == 0 or NULL if no such element exists in the tree.
◆ av_tree_insert()
void* av_tree_insert
(
struct
AVTreeNode **
rootp,
void *
key,
int(*)(const void *
key, const void *
b)
cmp,
)
Insert or remove an element.
If *next is NULL, then the supplied element will be removed if it exists. If *next is non-NULL, then the supplied element will be inserted, unless it already exists in the tree.
- Parameters
-
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.
key pointer to the element key to insert in the tree
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_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. You might want to define a function like:
int (*
cmp)(
void *
key,
const void *
b),
{
if (!*next)
}
{
}
cmp compare function used to compare elements in the tree, API identical to that of Standard C's qsort
- Returns
- 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.
Definition at line 59 of file tree.c.
Referenced by add_entry(), alloc_and_insert_node(), av_tree_insert(), dts2pts_filter(), ff_nut_add_sp(), and main().
◆ av_tree_destroy()
◆ av_tree_enumerate()
void *
opaque,
int(*)(void *opaque, void *elem)
cmp,
int(*)(void *opaque, void *elem)
enu
)
Apply enu(opaque, &elem) to all the elements in the tree in a given range.
- Parameters
-
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 tree.
Definition at line 155 of file tree.c.
Referenced by av_tree_enumerate(), cache_close(), command(), dts2pts_flush(), ff_nut_free_sp(), h264_filter(), h264_queue_frame(), hevc_queue_frame(), and uninit().
Variable Documentation
◆ av_tree_node_size
const int av_tree_node_size
void * av_tree_insert(AVTreeNode **tp, void *key, int(*cmp)(const void *key, const void *b), AVTreeNode **next)
Insert or remove an element.
const int av_tree_node_size
static av_always_inline int cmp(MPVEncContext *const s, const int x, const int y, const int subx, const int suby, const int size, const int h, int ref_index, int src_index, me_cmp_func cmp_func, me_cmp_func chroma_cmp_func, const int flags)
compares a block (either a full macroblock or a partition thereof) against a proposed motion-compensa...
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
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