libavutil/tree.c File Reference

#include "common.h"
#include "log.h"
#include "tree.h"

Go to the source code of this file.

Data Structures

struct AVTreeNode

Functions

void * av_tree_find (const AVTreeNode *t, void *key, int(*cmp)(void *key, const void *b), void *next[2])

void * av_tree_insert (AVTreeNode **tp, void *key, int(*cmp)(void *key, const void *b), AVTreeNode **next)

Inserts or removes an element.

void av_tree_destroy (AVTreeNode *t)

Variables

const int av_tree_node_size = sizeof(AVTreeNode)

Function Documentation

void av_tree_destroy ( AVTreeNode * t )

Definition at line 130 of file tree.c.

Referenced by av_tree_destroy().

void* av_tree_find ( const AVTreeNode * t,

void * key,

int(*)(void *key, const void *b) cmp,

void * next[2]

)

Definition at line 33 of file tree.c.

Referenced by av_tree_insert(), read_seek(), and write_packet().

void* av_tree_insert ( struct AVTreeNode ** rootp,

void * key,

int(*)(void *key, const void *b) cmp,

struct AVTreeNode ** next

)

Inserts or removes 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 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.

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 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: 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); } void *tree_remove(struct AVTreeNode **rootp, void *key, int (*cmp)(void *key, const void *b, AVTreeNode **next)){ if(*next) av_freep(next); return av_tree_insert(rootp, key, cmp, next); }

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 50 of file tree.c.

Referenced by av_tree_insert(), and ff_nut_add_sp().

Variable Documentation

const int av_tree_node_size = sizeof(AVTreeNode)

Definition at line 31 of file tree.c.

Referenced by ff_nut_add_sp().

Generated on Fri Oct 26 02:35:46 2012 for FFmpeg by doxygen 1.5.8