From 3b6e35f5126957174a5271e41d9d27b155fb64d2 Mon Sep 17 00:00:00 2001
From: Nikita <abracham.mitchell@gmail.com>
Date: Wed, 30 Dec 2015 14:48:12 +0300
Subject: [PATCH] RMap.putIfAbsent optimization

---
 src/main/java/org/redisson/RedissonMap.java | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/main/java/org/redisson/RedissonMap.java b/src/main/java/org/redisson/RedissonMap.java
index ac7b0b0f6..25ccf0161 100644
--- a/src/main/java/org/redisson/RedissonMap.java
+++ b/src/main/java/org/redisson/RedissonMap.java
@@ -194,8 +194,7 @@ public class RedissonMap<K, V> extends RedissonExpirable implements RMap<K, V> {
     @Override
     public Future<V> putIfAbsentAsync(K key, V value) {
         return commandExecutor.evalWriteAsync(getName(), codec, EVAL_PUT,
-                "if redis.call('hexists', KEYS[1], ARGV[1]) == 0 then "
-                    + "redis.call('hset', KEYS[1], ARGV[1], ARGV[2]); "
+                 "if redis.call('hsetnx', KEYS[1], ARGV[1], ARGV[2]) == 1 then "
                     + "return nil "
                 + "else "
                     + "return redis.call('hget', KEYS[1], ARGV[1]) "