This patch optimized the code by previously getpos function call. Therefore, It's takes the convenience to understand logic of code.
Signed-off-by: Leno Hou <[email protected]> --- lib/btree.c | 41 +++++++++++++++++------------------------ 1 file changed, 17 insertions(+), 24 deletions(-) diff --git a/lib/btree.c b/lib/btree.c index f93a945..87d690f 100644 --- a/lib/btree.c +++ b/lib/btree.c @@ -238,6 +238,19 @@ static int keyzero(struct btree_geo *geo, unsigned long *key) return 1; } +static int getpos(struct btree_geo *geo, unsigned long *node, + unsigned long *key) +{ + int i; + + for (i = 0; i < geo->no_pairs; i++) { + if (keycmp(geo, node, i, key) <= 0) + break; + } + return i; +} + + void *btree_lookup(struct btree_head *head, struct btree_geo *geo, unsigned long *key) { @@ -248,9 +261,7 @@ void *btree_lookup(struct btree_head *head, struct btree_geo *geo, return NULL; for ( ; height > 1; height--) { - for (i = 0; i < geo->no_pairs; i++) - if (keycmp(geo, node, i, key) <= 0) - break; + i = getpos(geo, node, key); if (i == geo->no_pairs) return NULL; node = bval(geo, node, i); @@ -278,9 +289,7 @@ int btree_update(struct btree_head *head, struct btree_geo *geo, return -ENOENT; for ( ; height > 1; height--) { - for (i = 0; i < geo->no_pairs; i++) - if (keycmp(geo, node, i, key) <= 0) - break; + i = getpos(geo, node, key); if (i == geo->no_pairs) return -ENOENT; node = bval(geo, node, i); @@ -326,9 +335,7 @@ void *btree_get_prev(struct btree_head *head, struct btree_geo *geo, node = head->node; for (height = head->height ; height > 1; height--) { - for (i = 0; i < geo->no_pairs; i++) - if (keycmp(geo, node, i, key) <= 0) - break; + i = getpos(geo, node, key); if (i == geo->no_pairs) goto miss; oldnode = node; @@ -360,18 +367,6 @@ void *btree_get_prev(struct btree_head *head, struct btree_geo *geo, } EXPORT_SYMBOL_GPL(btree_get_prev); -static int getpos(struct btree_geo *geo, unsigned long *node, - unsigned long *key) -{ - int i; - - for (i = 0; i < geo->no_pairs; i++) { - if (keycmp(geo, node, i, key) <= 0) - break; - } - return i; -} - static int getfill(struct btree_geo *geo, unsigned long *node, int start) { int i; @@ -392,9 +387,7 @@ static unsigned long *find_level(struct btree_head *head, struct btree_geo *geo, int i, height; for (height = head->height; height > level; height--) { - for (i = 0; i < geo->no_pairs; i++) - if (keycmp(geo, node, i, key) <= 0) - break; + i = getpos(geo, node, key); if ((i == geo->no_pairs) || !bval(geo, node, i)) { /* right-most key is too large, update it */ -- 1.8.3.1
