nilfs2: reduce repetitive calculation of max number of child nodes
The current btree implementation repeats the same calculation on the
maximum number of child nodes. This is because a few low level
routines use the calculation for index addressing in a btree node
block.
This reduces the calculation by explicitly passing the maximum number
of child nodes (ncmax) through their argument.
This changes parameter passing of the following functions:
- nilfs_btree_node_dptrs
- nilfs_btree_node_get_ptr
- nilfs_btree_node_set_ptr
- nilfs_btree_node_init
- nilfs_btree_node_move_left
- nilfs_btree_node_move_right
- nilfs_btree_node_insert
- nilfs_btree_node_delete, and
- nilfs_btree_get_node
The following functions are removed:
- nilfs_btree_node_nchildren_min
- nilfs_btree_node_nchildren_max
Most middle level btree operations are rewritten to pass a proper
ncmax value depending on whether each occurrence of node is "root" or
not.
A constant NILFS_BTREE_ROOT_NCHILDREN_MAX is used for the root node,
whereas nilfs_btree_nchildren_per_block() function is used for
non-root nodes. If a node could be either root or a non-root node, an
output argument of nilfs_btree_get_node() is used to set up ncmax.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
1 file changed