Traverse the entries in a tree and its subtrees in post or pre order.
The entries will be traversed in the specified order, children subtrees
will be automatically loaded as required, and the callback will be
called once per entry with the current (relative) root for the entry and
the entry data itself.
If the callback returns a positive value, the passed entry will be
skipped on the traversal (in pre mode). A negative value stops the walk.
@param tree The tree to walk
@param mode Traversal mode (pre or post-order)
@param callback Function to call on each tree entry
@param payload Opaque pointer to be passed on each callback
@return 0 or an error code
Traverse the entries in a tree and its subtrees in post or pre order.
The entries will be traversed in the specified order, children subtrees will be automatically loaded as required, and the callback will be called once per entry with the current (relative) root for the entry and the entry data itself.
If the callback returns a positive value, the passed entry will be skipped on the traversal (in pre mode). A negative value stops the walk.
@param tree The tree to walk @param mode Traversal mode (pre or post-order) @param callback Function to call on each tree entry @param payload Opaque pointer to be passed on each callback @return 0 or an error code