Scripting: redis.NIL to return nil bulk replies.

[redis.git] / src / scripting.c

diff --git a/src/scripting.c b/src/scripting.c
index 8c89c923c0ce4331b7136dc453141b578b870758..fd1733f6553a283b756114764d4d426669c342e5 100644 (file)
--- a/src/scripting.c
+++ b/src/scripting.c
@@ -167,6 +167,13 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) {
     redisClient *c = server.lua_client;
     sds reply;
 
+    /* Require at least one argument */
+    if (argc == 0) {
+        luaPushError(lua,
+            "Please specify at least one argument for redis.call()");
+        return 1;
+    }
+
     /* Build the arguments vector */
     argv = zmalloc(sizeof(robj*)*argc);
     for (j = 0; j < argc; j++) {
@@ -275,11 +282,10 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) {
      * reply as expected. */
     if ((cmd->flags & REDIS_CMD_SORT_FOR_SCRIPT) &&
         (reply[0] == '*' && reply[1] != '-')) {
-        /* Skip this step if command is SORT but output was already sorted */
-        if (cmd->proc != sortCommand || server.sort_dontsort)
             luaSortArray(lua);
     }
     sdsfree(reply);
+    c->reply_bytes = 0;
 
 cleanup:
     /* Clean up. Command code may have changed argv/argc so we use the
@@ -510,6 +516,14 @@ void scriptingInit(void) {
     lua_pushcfunction(lua, luaRedisSha1hexCommand);
     lua_settable(lua, -3);
 
+    /* redis.NIL */
+    lua_pushstring(lua, "NIL");
+    lua_newtable(lua);
+    lua_pushstring(lua, "nilbulk");
+    lua_pushboolean(lua, 1);
+    lua_settable(lua, -3);
+    lua_settable(lua, -3);
+
     /* Finally set the table as 'redis' global var. */
     lua_setglobal(lua,"redis");
 
@@ -604,9 +618,30 @@ void luaReplyToRedisReply(redisClient *c, lua_State *lua) {
         addReplyLongLong(c,(long long)lua_tonumber(lua,-1));
         break;
     case LUA_TTABLE:
-        /* We need to check if it is an array, an error, or a status reply.
-         * Error are returned as a single element table with 'err' field.
-         * Status replies are returned as single elment table with 'ok' field */
+        /* The table can be an array or it may be in a special format that
+         * Lua uses to return special Redis protocol data types.
+         *
+         * 1) Errors are retuned as a single element table with 'err' field.
+         * 2) Status reply are returned as a single element table with 'ok'
+         *    field.
+         * 3) A Redis nil bulk reply is returned as a single element table
+         *    with 'nilbulk' field set to true.
+         *
+         * All the rest is considered just an array and is translated into
+         * a Redis multi bulk reply. */
+
+        /* Nil bulk reply */
+        lua_pushstring(lua,"nilbulk");
+        lua_gettable(lua,-2);
+        t = lua_type(lua,-1);
+        if (t == LUA_TBOOLEAN) {
+            addReply(c,shared.nullbulk);
+            lua_pop(lua,2);
+            return;
+        }
+        lua_pop(lua,1);
+
+        /* Error reply */
         lua_pushstring(lua,"err");
         lua_gettable(lua,-2);
         t = lua_type(lua,-1);
@@ -618,8 +653,9 @@ void luaReplyToRedisReply(redisClient *c, lua_State *lua) {
             lua_pop(lua,2);
             return;
         }
-
         lua_pop(lua,1);
+
+        /* Status reply */
         lua_pushstring(lua,"ok");
         lua_gettable(lua,-2);
         t = lua_type(lua,-1);
@@ -630,6 +666,7 @@ void luaReplyToRedisReply(redisClient *c, lua_State *lua) {
             sdsfree(ok);
             lua_pop(lua,1);
         } else {
+            /* Multi bulk reply. */
             void *replylen = addDeferredMultiBulkLength(c);
             int j = 1, mbulklen = 0;