Added hmsetnx command

src/redis.c

@@ -195,6 +195,7 @@ struct redisCommand redisCommandTable[] = {
     {"hsetnx",hsetnxCommand,4,"wmF",0,NULL,1,1,1,0,0},
     {"hget",hgetCommand,3,"rF",0,NULL,1,1,1,0,0},
     {"hmset",hmsetCommand,-4,"wm",0,NULL,1,1,1,0,0},
+    {"hmsetnx",hmsetnxCommand,-4,"wm",0,NULL,1,1,1,0,0},
     {"hmget",hmgetCommand,-3,"r",0,NULL,1,1,1,0,0},
     {"hincrby",hincrbyCommand,4,"wmF",0,NULL,1,1,1,0,0},
     {"hincrbyfloat",hincrbyfloatCommand,4,"wmF",0,NULL,1,1,1,0,0},

src/redis.h

@@ -1485,6 +1485,7 @@ void hsetCommand(redisClient *c);
 void hsetnxCommand(redisClient *c);
 void hgetCommand(redisClient *c);
 void hmsetCommand(redisClient *c);
+void hmsetnxCommand(redisClient *c);
 void hmgetCommand(redisClient *c);
 void hdelCommand(redisClient *c);
 void hlenCommand(redisClient *c);

src/t_hash.c

@@ -513,6 +513,40 @@ void hmsetCommand(redisClient *c) {
     server.dirty++;
 }
 
+void hmsetnxCommand(redisClient *c) {
+    int i, busykeys = 0;
+    robj *o;
+
+    if ((c->argc % 2) == 1) {
+        addReplyError(c,"wrong number of arguments for HMSETNX");
+        return;
+    }
+
+    if ((o = hashTypeLookupWriteOrCreate(c,c->argv[1])) == NULL) return;
+    hashTypeTryConversion(o,c->argv,2,c->argc-1);
+
+    /* Handle the NX flag. The HMSETNX semantic is to return zero and don't
+     * set nothing at all if at least one already key exists. */
+    for (i = 2; i < c->argc; i += 2) {
+        if (hashTypeExists(o, c->argv[i])) {
+            busykeys++;
+        }
+        if (busykeys) {
+            addReply(c, shared.czero);
+            return;
+        }
+    }
+
+    for (i = 2; i < c->argc; i += 2) {
+         hashTypeTryObjectEncoding(o,&c->argv[i], &c->argv[i+1]);
+         hashTypeSet(o,c->argv[i],c->argv[i+1]);
+    }
+    addReply(c, shared.cone);
+    signalModifiedKey(c->db,c->argv[1]);
+    notifyKeyspaceEvent(REDIS_NOTIFY_HASH,"hset",c->argv[1],c->db->id);
+    server.dirty++;
+}
+
 void hincrbyCommand(redisClient *c) {
     long long value, incr, oldvalue;
     robj *o, *current, *new;

tests/unit/type/hash.tcl

@@ -132,6 +132,22 @@ start_server {tags {"hash"}} {
         r hmset bighash {*}$args
     } {OK}
 
+    test "HMSETNX - set empty hash" {
+        r del hash
+        assert_equal 1 [r hmsetnx hash key1 value1]
+        assert_equal "value1" [r hmget hash key1]
+    }
+
+    test "HMSETNX - set existing hash" {
+        r del hash
+        assert_equal 1 [r hmsetnx hash key1 value1]
+        assert_equal 0 [r hmsetnx hash key1 newvalue1 key2 value2]
+        assert_equal "value1" [r hmget hash key1]
+        assert_equal 0 [r hexists hash key2]
+        assert_equal 1 [r hmsetnx hash key2 value2]
+        assert_equal 1 [r hexists hash key2]
+    }
+
     test {HMGET against non existing key and fields} {
         set rv {}
         lappend rv [r hmget doesntexist __123123123__ __456456456__]