From f35368dd1cef11cdd310b07c74d74f45e3469c64 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Fri, 23 Mar 2012 15:02:15 -0700 Subject: prio_tree: cleanup prio_tree_left()/prio_tree_right() Introduce iter_walk_down()/iter_walk_up() to remove the common code between prio_tree_left() and prio_tree_right(). Signed-off-by: Xiao Guangrong Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/prio_tree.c | 78 +++++++++++++++++++++++++++------------------------------ 1 file changed, 37 insertions(+), 41 deletions(-) diff --git a/lib/prio_tree.c b/lib/prio_tree.c index 423eba80478..888e8b3a97e 100644 --- a/lib/prio_tree.c +++ b/lib/prio_tree.c @@ -304,6 +304,40 @@ void prio_tree_remove(struct prio_tree_root *root, struct prio_tree_node *node) cur = prio_tree_replace(root, cur->parent, cur); } +static void iter_walk_down(struct prio_tree_iter *iter) +{ + iter->mask >>= 1; + if (iter->mask) { + if (iter->size_level) + iter->size_level++; + return; + } + + if (iter->size_level) { + BUG_ON(!prio_tree_left_empty(iter->cur)); + BUG_ON(!prio_tree_right_empty(iter->cur)); + iter->size_level++; + iter->mask = ULONG_MAX; + } else { + iter->size_level = 1; + iter->mask = 1UL << (BITS_PER_LONG - 1); + } +} + +static void iter_walk_up(struct prio_tree_iter *iter) +{ + if (iter->mask == ULONG_MAX) + iter->mask = 1UL; + else if (iter->size_level == 1) + iter->mask = 1UL; + else + iter->mask <<= 1; + if (iter->size_level) + iter->size_level--; + if (!iter->size_level && (iter->value & iter->mask)) + iter->value ^= iter->mask; +} + /* * Following functions help to enumerate all prio_tree_nodes in the tree that * overlap with the input interval X [radix_index, heap_index]. The enumeration @@ -322,21 +356,7 @@ static struct prio_tree_node *prio_tree_left(struct prio_tree_iter *iter, if (iter->r_index <= *h_index) { iter->cur = iter->cur->left; - iter->mask >>= 1; - if (iter->mask) { - if (iter->size_level) - iter->size_level++; - } else { - if (iter->size_level) { - BUG_ON(!prio_tree_left_empty(iter->cur)); - BUG_ON(!prio_tree_right_empty(iter->cur)); - iter->size_level++; - iter->mask = ULONG_MAX; - } else { - iter->size_level = 1; - iter->mask = 1UL << (BITS_PER_LONG - 1); - } - } + iter_walk_down(iter); return iter->cur; } @@ -363,22 +383,7 @@ static struct prio_tree_node *prio_tree_right(struct prio_tree_iter *iter, if (iter->r_index <= *h_index) { iter->cur = iter->cur->right; - iter->mask >>= 1; - iter->value = value; - if (iter->mask) { - if (iter->size_level) - iter->size_level++; - } else { - if (iter->size_level) { - BUG_ON(!prio_tree_left_empty(iter->cur)); - BUG_ON(!prio_tree_right_empty(iter->cur)); - iter->size_level++; - iter->mask = ULONG_MAX; - } else { - iter->size_level = 1; - iter->mask = 1UL << (BITS_PER_LONG - 1); - } - } + iter_walk_down(iter); return iter->cur; } @@ -388,16 +393,7 @@ static struct prio_tree_node *prio_tree_right(struct prio_tree_iter *iter, static struct prio_tree_node *prio_tree_parent(struct prio_tree_iter *iter) { iter->cur = iter->cur->parent; - if (iter->mask == ULONG_MAX) - iter->mask = 1UL; - else if (iter->size_level == 1) - iter->mask = 1UL; - else - iter->mask <<= 1; - if (iter->size_level) - iter->size_level--; - if (!iter->size_level && (iter->value & iter->mask)) - iter->value ^= iter->mask; + iter_walk_up(iter); return iter->cur; } -- cgit v1.2.3-18-g5258