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authorXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>2012-03-23 15:02:15 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-03-23 16:58:36 -0700
commitf35368dd1cef11cdd310b07c74d74f45e3469c64 (patch)
treebeefa4e4759f29917749fcdfb2102adc16d48cda /lib/prio_tree.c
parentf42240d729b97a01e863b8c24177ec4e54885357 (diff)
downloadlinux-sh-f35368dd1cef11cdd310b07c74d74f45e3469c64.tar.gz
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 <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/prio_tree.c')
-rw-r--r--lib/prio_tree.c78
1 files changed, 37 insertions, 41 deletions
diff --git a/lib/prio_tree.c b/lib/prio_tree.c
index 423eba80478b..888e8b3a97ea 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;
}