From 923041cb0ab7c1795e74fa1ce4b38a6114727a3c Mon Sep 17 00:00:00 2001

From: Michal Schmidt <mschmidt@redhat.com>

Date: Sun, 10 Aug 2014 23:35:27 +0200

Subject: [PATCH] hashmap: minor hashmap_replace optimization

When hashmap_replace detects no such key exists yet, it calls hashmap_put that

performs the same check again. Avoid that by splitting the core of hashmap_put

into a separate function.

---

 src/shared/hashmap.c | 34 +++++++++++++++++++++-------------

 1 file changed, 21 insertions(+), 13 deletions(-)

diff --git a/src/shared/hashmap.c b/src/shared/hashmap.c

index 1eadeced5c..4c517059f6 100644

--- a/src/shared/hashmap.c

+++ b/src/shared/hashmap.c

@@ -488,19 +488,10 @@ static bool resize_buckets(Hashmap *h) {

         return true;

 }

-int hashmap_put(Hashmap *h, const void *key, void *value) {

-        struct hashmap_entry *e;

-        unsigned hash;

-

-        assert(h);

+static int __hashmap_put(Hashmap *h, const void *key, void *value, unsigned hash) {

+        /* For when we know no such entry exists yet */

-        hash = bucket_hash(h, key);

-        e = hash_scan(h, hash, key);

-        if (e) {

-                if (e->value == value)

-                        return 0;

-                return -EEXIST;

-        }

+        struct hashmap_entry *e;

         if (resize_buckets(h))

                 hash = bucket_hash(h, key);

@@ -521,6 +512,23 @@ int hashmap_put(Hashmap *h, const void *key, void *value) {

         return 1;

 }

+int hashmap_put(Hashmap *h, const void *key, void *value) {

+        struct hashmap_entry *e;

+        unsigned hash;

+

+        assert(h);

+

+        hash = bucket_hash(h, key);

+        e = hash_scan(h, hash, key);

+        if (e) {

+                if (e->value == value)

+                        return 0;

+                return -EEXIST;

+        }

+

+        return __hashmap_put(h, key, value, hash);

+}

+

 int hashmap_replace(Hashmap *h, const void *key, void *value) {

         struct hashmap_entry *e;

         unsigned hash;

@@ -535,7 +543,7 @@ int hashmap_replace(Hashmap *h, const void *key, void *value) {

                 return 0;

         }

-        return hashmap_put(h, key, value);

+        return __hashmap_put(h, key, value, hash);

 }

 int hashmap_update(Hashmap *h, const void *key, void *value) {