Add the KEYDB.MEXISTS command, see issue Snapchat#203

Author: JohnSully

src/db.cpp

@@ -683,6 +683,13 @@ void existsCommand(client *c) {
     addReplyLongLong(c,count);
 }
 
+void mexistsCommand(client *c) {
+    addReplyArrayLen(c, c->argc - 1);
+    for (int j = 1; j < c->argc; ++j) {
+        addReplyBool(c, lookupKeyRead(c->db, c->argv[j]));
+    }
+}
+
 void selectCommand(client *c) {
     long id;
 

src/help.h

@@ -1325,7 +1325,12 @@ struct commandHelp {
     "Rename a hash key, copying the value.",
     4,
     "6.5.3"
-    }
+    },
+    { "KEYDB.MEXISTS",
+    "key [key ...]",
+    "Determine if a key exists",
+    0,
+    "6.5.12" },
 };
 
 #endif

src/server.cpp

@@ -247,6 +247,10 @@ struct redisCommand redisCommandTable[] = {
      "read-only fast @keyspace",
      0,NULL,1,-1,1,0,0,0},
 
+    {"keydb.mexists",mexistsCommand,-2,
+     "read-only fast @keyspace",
+     0,NULL,1,-1,1,0,0,0},
+
     {"setbit",setbitCommand,4,
      "write use-memory @bitmap",
      0,NULL,1,1,1,0,0,0},

src/server.h

@@ -2822,6 +2822,7 @@ void getCommand(client *c);
 void delCommand(client *c);
 void unlinkCommand(client *c);
 void existsCommand(client *c);
+void mexistsCommand(client *c);
 void setbitCommand(client *c);
 void getbitCommand(client *c);
 void bitfieldCommand(client *c);