[PATCH] libsepol: hashtab: save one comparison on hit

[Christian Göttsche <cgoettsche@xxxxxxxxxxxxx>]

From: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>

When the comparison function returns 0, avoid a repeated call to it.

Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
---
 libsepol/src/hashtab.c | 53 +++++++++++++++++++++++++-----------------
 1 file changed, 32 insertions(+), 21 deletions(-)

diff --git a/libsepol/src/hashtab.c b/libsepol/src/hashtab.c
index 2af3a9bf..399582b1 100644
--- a/libsepol/src/hashtab.c
+++ b/libsepol/src/hashtab.c
@@ -112,15 +112,17 @@ int hashtab_insert(hashtab_t h, hashtab_key_t key, hashtab_datum_t datum)
 	hashtab_check_resize(h);
 
 	hvalue = h->hash_value(h, key);
-	prev = NULL;
-	cur = h->htable[hvalue];
-	while (cur && h->keycmp(h, key, cur->key) > 0) {
-		prev = cur;
-		cur = cur->next;
-	}
 
-	if (cur && (h->keycmp(h, key, cur->key) == 0))
-		return SEPOL_EEXIST;
+	for (prev = NULL, cur = h->htable[hvalue]; cur; prev = cur, cur = cur->next) {
+		int cmp;
+
+		cmp = h->keycmp(h, key, cur->key);
+		if (cmp > 0)
+			continue;
+		if (cmp == 0)
+			return SEPOL_EEXIST;
+		break;
+	}
 
 	newnode = (hashtab_ptr_t) malloc(sizeof(hashtab_node_t));
 	if (newnode == NULL)
@@ -151,14 +153,19 @@ int hashtab_remove(hashtab_t h, hashtab_key_t key,
 		return SEPOL_ENOENT;
 
 	hvalue = h->hash_value(h, key);
-	last = NULL;
-	cur = h->htable[hvalue];
-	while (cur != NULL && h->keycmp(h, key, cur->key) > 0) {
-		last = cur;
-		cur = cur->next;
+
+	for (last = NULL, cur = h->htable[hvalue]; cur; last = cur, cur = cur->next) {
+		int cmp;
+
+		cmp = h->keycmp(h, key, cur->key);
+		if (cmp > 0)
+			continue;
+		if (cmp == 0)
+			break;
+		return SEPOL_ENOENT;
 	}
 
-	if (cur == NULL || (h->keycmp(h, key, cur->key) != 0))
+	if (cur == NULL)
 		return SEPOL_ENOENT;
 
 	if (last == NULL)
@@ -183,14 +190,18 @@ hashtab_datum_t hashtab_search(hashtab_t h, const_hashtab_key_t key)
 		return NULL;
 
 	hvalue = h->hash_value(h, key);
-	cur = h->htable[hvalue];
-	while (cur != NULL && h->keycmp(h, key, cur->key) > 0)
-		cur = cur->next;
-
-	if (cur == NULL || (h->keycmp(h, key, cur->key) != 0))
-		return NULL;
+	for (cur = h->htable[hvalue]; cur; cur = cur->next) {
+		int cmp;
+
+		cmp = h->keycmp(h, key, cur->key);
+		if (cmp > 0)
+			continue;
+		if (cmp == 0)
+			return cur->datum;
+		break;
+	}
 
-	return cur->datum;
+	return NULL;
 }
 
 void hashtab_destroy(hashtab_t h)
-- 
2.45.1