int luaRedisGenericCommand(lua_State *lua, int raise_error) {
    int j, argc = lua_gettop(lua);
    struct redisCommand *cmd;
    client *c = server.lua_client;
    sds reply;

    /* Cached across calls. */
    static robj **argv = NULL;
    static int argv_size = 0;
    static robj *cached_objects[LUA_CMD_OBJCACHE_SIZE];
    static size_t cached_objects_len[LUA_CMD_OBJCACHE_SIZE];
    static int inuse = 0;   /* Recursive calls detection. */

    /* By using Lua debug hooks it is possible to trigger a recursive call
     * to luaRedisGenericCommand(), which normally should never happen.
     * To make this function reentrant is futile and makes it slower, but
     * we should at least detect such a misuse, and abort. */
    if (inuse) {
        char *recursion_warning =
            "luaRedisGenericCommand() recursive call detected. "
            "Are you doing funny stuff with Lua debug hooks?";
        serverLog(LL_WARNING,"%s",recursion_warning);
        luaPushError(lua,recursion_warning);
        return 1;
    }
    inuse++;

    /* Require at least one argument */
    if (argc == 0) {
        luaPushError(lua,
            "Please specify at least one argument for redis.call()");
        inuse--;
        return raise_error ? luaRaiseError(lua) : 1;
    }

    /* Build the arguments vector */
    if (argv_size < argc) {
        argv = zrealloc(argv,sizeof(robj*)*argc);
        argv_size = argc;
    }

    for (j = 0; j < argc; j++) {
        char *obj_s;
        size_t obj_len;
        char dbuf[64];

        if (lua_type(lua,j+1) == LUA_TNUMBER) {
            /* We can't use lua_tolstring() for number -> string conversion
             * since Lua uses a format specifier that loses precision. */
            lua_Number num = lua_tonumber(lua,j+1);

            obj_len = snprintf(dbuf,sizeof(dbuf),"%.17g",(double)num);
            obj_s = dbuf;
        } else {
            obj_s = (char*)lua_tolstring(lua,j+1,&obj_len);
            if (obj_s == NULL) break; /* Not a string. */
        }

        /* Try to use a cached object. */
        if (j < LUA_CMD_OBJCACHE_SIZE && cached_objects[j] &&
            cached_objects_len[j] >= obj_len)
        {
            sds s = cached_objects[j]->ptr;
            argv[j] = cached_objects[j];
            cached_objects[j] = NULL;
            memcpy(s,obj_s,obj_len+1);
            sdssetlen(s, obj_len);
        } else {
            argv[j] = createStringObject(obj_s, obj_len);
        }
    }

    /* Check if one of the arguments passed by the Lua script
     * is not a string or an integer (lua_isstring() return true for
     * integers as well). */
    if (j != argc) {
        j--;
        while (j >= 0) {
            decrRefCount(argv[j]);
            j--;
        }
        luaPushError(lua,
            "Lua redis() command arguments must be strings or integers");
        inuse--;
        return raise_error ? luaRaiseError(lua) : 1;
    }

    /* Setup our fake client for command execution */
    c->argv = argv;
    c->argc = argc;
    c->user = server.lua_caller->user;

    /* Process module hooks */
    moduleCallCommandFilters(c);
    argv = c->argv;
    argc = c->argc;

    /* Log the command if debugging is active. */
    if (ldb.active && ldb.step) {
        sds cmdlog = sdsnew("<redis>");
        for (j = 0; j < c->argc; j++) {
            if (j == 10) {
                cmdlog = sdscatprintf(cmdlog," ... (%d more)",
                    c->argc-j-1);
                break;
            } else {
                cmdlog = sdscatlen(cmdlog," ",1);
                cmdlog = sdscatsds(cmdlog,c->argv[j]->ptr);
            }
        }
        ldbLog(cmdlog);
    }

    /* Command lookup */
    cmd = lookupCommand(argv[0]->ptr);
    if (!cmd || ((cmd->arity > 0 && cmd->arity != argc) ||
                   (argc < -cmd->arity)))
    {
        if (cmd)
            luaPushError(lua,
                "Wrong number of args calling Redis command From Lua script");
        else
            luaPushError(lua,"Unknown Redis command called from Lua script");
        goto cleanup;
    }
    c->cmd = c->lastcmd = cmd;

    /* There are commands that are not allowed inside scripts. */
    if (cmd->flags & CMD_NOSCRIPT) {
        luaPushError(lua, "This Redis command is not allowed from scripts");
        goto cleanup;
    }

    /* Check the ACLs. */
    int acl_keypos;
    int acl_retval = ACLCheckCommandPerm(c,&acl_keypos);
    if (acl_retval != ACL_OK) {
        addACLLogEntry(c,acl_retval,acl_keypos,NULL);
        if (acl_retval == ACL_DENIED_CMD)
            luaPushError(lua, "The user executing the script can't run this "
                              "command or subcommand");
        else
            luaPushError(lua, "The user executing the script can't access "
                              "at least one of the keys mentioned in the "
                              "command arguments");
        goto cleanup;
    }

    /* Write commands are forbidden against read-only slaves, or if a
     * command marked as non-deterministic was already called in the context
     * of this script. */
    if (cmd->flags & CMD_WRITE) {
        int deny_write_type = writeCommandsDeniedByDiskError();
        if (server.lua_random_dirty && !server.lua_replicate_commands) {
            luaPushError(lua,
                "Write commands not allowed after non deterministic commands. Call redis.replicate_commands() at the start of your script in order to switch to single commands replication mode.");
            goto cleanup;
        } else if (server.masterhost && server.repl_slave_ro &&
                   !server.loading &&
                   !(server.lua_caller->flags & CLIENT_MASTER))
        {
            luaPushError(lua, shared.roslaveerr->ptr);
            goto cleanup;
        } else if (deny_write_type != DISK_ERROR_TYPE_NONE) {
            if (deny_write_type == DISK_ERROR_TYPE_RDB) {
                luaPushError(lua, shared.bgsaveerr->ptr);
            } else {
                sds aof_write_err = sdscatfmt(sdsempty(),
                    "-MISCONF Errors writing to the AOF file: %s\r\n",
                    strerror(server.aof_last_write_errno));
                luaPushError(lua, aof_write_err);
                sdsfree(aof_write_err);
            }
            goto cleanup;
        }
    }

    /* If we reached the memory limit configured via maxmemory, commands that
     * could enlarge the memory usage are not allowed, but only if this is the
     * first write in the context of this script, otherwise we can't stop
     * in the middle. */
    if (server.maxmemory &&             /* Maxmemory is actually enabled. */
        !server.loading &&              /* Don't care about mem if loading. */
        !server.masterhost &&           /* Slave must execute the script. */
        server.lua_write_dirty == 0 &&  /* Script had no side effects so far. */
        server.lua_oom &&               /* Detected OOM when script start. */
        (cmd->flags & CMD_DENYOOM))
    {
        luaPushError(lua, shared.oomerr->ptr);
        goto cleanup;
    }

    if (cmd->flags & CMD_RANDOM) server.lua_random_dirty = 1;
    if (cmd->flags & CMD_WRITE) server.lua_write_dirty = 1;

    /* If this is a Redis Cluster node, we need to make sure Lua is not
     * trying to access non-local keys, with the exception of commands
     * received from our master or when loading the AOF back in memory. */
    if (server.cluster_enabled && !server.loading &&
        !(server.lua_caller->flags & CLIENT_MASTER))
    {
        int error_code;
        /* Duplicate relevant flags in the lua client. */
        c->flags &= ~(CLIENT_READONLY|CLIENT_ASKING);
        c->flags |= server.lua_caller->flags & (CLIENT_READONLY|CLIENT_ASKING);
        if (getNodeByQuery(c,c->cmd,c->argv,c->argc,NULL,&error_code) !=
                           server.cluster->myself)
        {
            if (error_code == CLUSTER_REDIR_DOWN_RO_STATE) { 
                luaPushError(lua,
                    "Lua script attempted to execute a write command while the "
                    "cluster is down and readonly");
            } else if (error_code == CLUSTER_REDIR_DOWN_STATE) { 
                luaPushError(lua,
                    "Lua script attempted to execute a command while the "
                    "cluster is down");
            } else {
                luaPushError(lua,
                    "Lua script attempted to access a non local key in a "
                    "cluster node");
            }

            goto cleanup;
        }
    }

    /* If we are using single commands replication, we need to wrap what
     * we propagate into a MULTI/EXEC block, so that it will be atomic like
     * a Lua script in the context of AOF and slaves. */
    if (server.lua_replicate_commands &&
        !server.lua_multi_emitted &&
        !(server.lua_caller->flags & CLIENT_MULTI) &&
        server.lua_write_dirty &&
        server.lua_repl != PROPAGATE_NONE)
    {
        execCommandPropagateMulti(server.lua_caller);
        server.lua_multi_emitted = 1;
        /* Now we are in the MULTI context, the lua_client should be
         * flag as CLIENT_MULTI. */
        c->flags |= CLIENT_MULTI;
    }

    /* Run the command */
    int call_flags = CMD_CALL_SLOWLOG | CMD_CALL_STATS;
    if (server.lua_replicate_commands) {
        /* Set flags according to redis.set_repl() settings. */
        if (server.lua_repl & PROPAGATE_AOF)
            call_flags |= CMD_CALL_PROPAGATE_AOF;
        if (server.lua_repl & PROPAGATE_REPL)
            call_flags |= CMD_CALL_PROPAGATE_REPL;
    }
    call(c,call_flags);

    /* Convert the result of the Redis command into a suitable Lua type.
     * The first thing we need is to create a single string from the client
     * output buffers. */
    if (listLength(c->reply) == 0 && c->bufpos < PROTO_REPLY_CHUNK_BYTES) {
        /* This is a fast path for the common case of a reply inside the
         * client static buffer. Don't create an SDS string but just use
         * the client buffer directly. */
        c->buf[c->bufpos] = '\0';
        reply = c->buf;
        c->bufpos = 0;
    } else {
        reply = sdsnewlen(c->buf,c->bufpos);
        c->bufpos = 0;
        while(listLength(c->reply)) {
            clientReplyBlock *o = listNodeValue(listFirst(c->reply));

            reply = sdscatlen(reply,o->buf,o->used);
            listDelNode(c->reply,listFirst(c->reply));
        }
    }
    if (raise_error && reply[0] != '-') raise_error = 0;
    redisProtocolToLuaType(lua,reply);

    /* If the debugger is active, log the reply from Redis. */
    if (ldb.active && ldb.step)
        ldbLogRedisReply(reply);

    /* Sort the output array if needed, assuming it is a non-null multi bulk
     * reply as expected. */
    if ((cmd->flags & CMD_SORT_FOR_SCRIPT) &&
        (server.lua_replicate_commands == 0) &&
        (reply[0] == '*' && reply[1] != '-')) {
            luaSortArray(lua);
    }
    if (reply != c->buf) sdsfree(reply);
    c->reply_bytes = 0;

cleanup:
    /* Clean up. Command code may have changed argv/argc so we use the
     * argv/argc of the client instead of the local variables. */
    for (j = 0; j < c->argc; j++) {
        robj *o = c->argv[j];

        /* Try to cache the object in the cached_objects array.
         * The object must be small, SDS-encoded, and with refcount = 1
         * (we must be the only owner) for us to cache it. */
        if (j < LUA_CMD_OBJCACHE_SIZE &&
            o->refcount == 1 &&
            (o->encoding == OBJ_ENCODING_RAW ||
             o->encoding == OBJ_ENCODING_EMBSTR) &&
            sdslen(o->ptr) <= LUA_CMD_OBJCACHE_MAX_LEN)
        {
            sds s = o->ptr;
            if (cached_objects[j]) decrRefCount(cached_objects[j]);
            cached_objects[j] = o;
            cached_objects_len[j] = sdsalloc(s);
        } else {
            decrRefCount(o);
        }
    }

    if (c->argv != argv) {
        zfree(c->argv);
        argv = NULL;
        argv_size = 0;
    }

    c->user = NULL;

    if (raise_error) {
        /* If we are here we should have an error in the stack, in the
         * form of a table with an "err" field. Extract the string to
         * return the plain error. */
        inuse--;
        return luaRaiseError(lua);
    }
    inuse--;
    return 1;
}
int luaRedisGenericCommand(lua_State *lua, int raise_error) {
    int j, argc = lua_gettop(lua);
    struct redisCommand *cmd;
    client *c = server.lua_client;
    sds reply;

     
    static robj **argv = NULL;
    static int argv_size = 0;
    static robj *cached_objects[LUA_CMD_OBJCACHE_SIZE];
    static size_t cached_objects_len[LUA_CMD_OBJCACHE_SIZE];
    static int inuse = 0;    

     
    if (inuse) {
        char *recursion_warning =
            "luaRedisGenericCommand() recursive call detected. "
            "Are you doing funny stuff with Lua debug hooks?";
        serverLog(LL_WARNING,"%s",recursion_warning);
        luaPushError(lua,recursion_warning);
        return 1;
    }
    inuse++;

     
    if (argc == 0) {
        luaPushError(lua,
            "Please specify at least one argument for redis.call()");
        inuse--;
        return raise_error ? luaRaiseError(lua) : 1;
    }

     
    if (argv_size < argc) {
        argv = zrealloc(argv,sizeof(robj*)*argc);
        argv_size = argc;
    }

    for (j = 0; j < argc; j++) {
        char *obj_s;
        size_t obj_len;
        char dbuf[64];

        if (lua_type(lua,j+1) == LUA_TNUMBER) {
             
            lua_Number num = lua_tonumber(lua,j+1);

            obj_len = snprintf(dbuf,sizeof(dbuf),"%.17g",(double)num);
            obj_s = dbuf;
        } else {
            obj_s = (char*)lua_tolstring(lua,j+1,&obj_len);
            if (obj_s == NULL) break;  
        }

         
        if (j < LUA_CMD_OBJCACHE_SIZE && cached_objects[j] &&
            cached_objects_len[j] >= obj_len)
        {
            sds s = cached_objects[j]->ptr;
            argv[j] = cached_objects[j];
            cached_objects[j] = NULL;
            memcpy(s,obj_s,obj_len+1);
            sdssetlen(s, obj_len);
        } else {
            argv[j] = createStringObject(obj_s, obj_len);
        }
    }

     
    if (j != argc) {
        j--;
        while (j >= 0) {
            decrRefCount(argv[j]);
            j--;
        }
        luaPushError(lua,
            "Lua redis() command arguments must be strings or integers");
        inuse--;
        return raise_error ? luaRaiseError(lua) : 1;
    }

     
    c->argv = argv;
    c->argc = argc;
    c->user = server.lua_caller->user;

     
    moduleCallCommandFilters(c);
    argv = c->argv;
    argc = c->argc;

     
    if (ldb.active && ldb.step) {
        sds cmdlog = sdsnew("<redis>");
        for (j = 0; j < c->argc; j++) {
            if (j == 10) {
                cmdlog = sdscatprintf(cmdlog," ... (%d more)",
                    c->argc-j-1);
                break;
            } else {
                cmdlog = sdscatlen(cmdlog," ",1);
                cmdlog = sdscatsds(cmdlog,c->argv[j]->ptr);
            }
        }
        ldbLog(cmdlog);
    }

     
    cmd = lookupCommand(argv[0]->ptr);
    if (!cmd || ((cmd->arity > 0 && cmd->arity != argc) ||
                   (argc < -cmd->arity)))
    {
        if (cmd)
            luaPushError(lua,
                "Wrong number of args calling Redis command From Lua script");
        else
            luaPushError(lua,"Unknown Redis command called from Lua script");
        goto cleanup;
    }
    c->cmd = c->lastcmd = cmd;

     
    if (cmd->flags & CMD_NOSCRIPT) {
        luaPushError(lua, "This Redis command is not allowed from scripts");
        goto cleanup;
    }

     
    int acl_keypos;
    int acl_retval = ACLCheckCommandPerm(c,&acl_keypos);
    if (acl_retval != ACL_OK) {
        addACLLogEntry(c,acl_retval,acl_keypos,NULL);
        if (acl_retval == ACL_DENIED_CMD)
            luaPushError(lua, "The user executing the script can't run this "
                              "command or subcommand");
        else
            luaPushError(lua, "The user executing the script can't access "
                              "at least one of the keys mentioned in the "
                              "command arguments");
        goto cleanup;
    }

     
    if (cmd->flags & CMD_WRITE) {
        int deny_write_type = writeCommandsDeniedByDiskError();
        if (server.lua_random_dirty && !server.lua_replicate_commands) {
            luaPushError(lua,
                "Write commands not allowed after non deterministic commands. Call redis.replicate_commands() at the start of your script in order to switch to single commands replication mode.");
            goto cleanup;
        } else if (server.masterhost && server.repl_slave_ro &&
                   !server.loading &&
                   !(server.lua_caller->flags & CLIENT_MASTER))
        {
            luaPushError(lua, shared.roslaveerr->ptr);
            goto cleanup;
        } else if (deny_write_type != DISK_ERROR_TYPE_NONE) {
            if (deny_write_type == DISK_ERROR_TYPE_RDB) {
                luaPushError(lua, shared.bgsaveerr->ptr);
            } else {
                sds aof_write_err = sdscatfmt(sdsempty(),
                    "-MISCONF Errors writing to the AOF file: %s\r\n",
                    strerror(server.aof_last_write_errno));
                luaPushError(lua, aof_write_err);
                sdsfree(aof_write_err);
            }
            goto cleanup;
        }
    }

     
    if (server.maxmemory &&              
        !server.loading &&               
        !server.masterhost &&            
        server.lua_write_dirty == 0 &&   
        server.lua_oom &&                
        (cmd->flags & CMD_DENYOOM))
    {
        luaPushError(lua, shared.oomerr->ptr);
        goto cleanup;
    }

    if (cmd->flags & CMD_RANDOM) server.lua_random_dirty = 1;
    if (cmd->flags & CMD_WRITE) server.lua_write_dirty = 1;

     
    if (server.cluster_enabled && !server.loading &&
        !(server.lua_caller->flags & CLIENT_MASTER))
    {
        int error_code;
         
        c->flags &= ~(CLIENT_READONLY|CLIENT_ASKING);
        c->flags |= server.lua_caller->flags & (CLIENT_READONLY|CLIENT_ASKING);
        if (getNodeByQuery(c,c->cmd,c->argv,c->argc,NULL,&error_code) !=
                           server.cluster->myself)
        {
            if (error_code == CLUSTER_REDIR_DOWN_RO_STATE) { 
                luaPushError(lua,
                    "Lua script attempted to execute a write command while the "
                    "cluster is down and readonly");
            } else if (error_code == CLUSTER_REDIR_DOWN_STATE) { 
                luaPushError(lua,
                    "Lua script attempted to execute a command while the "
                    "cluster is down");
            } else {
                luaPushError(lua,
                    "Lua script attempted to access a non local key in a "
                    "cluster node");
            }

            goto cleanup;
        }
    }

     
    if (server.lua_replicate_commands &&
        !server.lua_multi_emitted &&
        !(server.lua_caller->flags & CLIENT_MULTI) &&
        server.lua_write_dirty &&
        server.lua_repl != PROPAGATE_NONE)
    {
        execCommandPropagateMulti(server.lua_caller);
        server.lua_multi_emitted = 1;
         
        c->flags |= CLIENT_MULTI;
    }

     
    int call_flags = CMD_CALL_SLOWLOG | CMD_CALL_STATS;
    if (server.lua_replicate_commands) {
         
        if (server.lua_repl & PROPAGATE_AOF)
            call_flags |= CMD_CALL_PROPAGATE_AOF;
        if (server.lua_repl & PROPAGATE_REPL)
            call_flags |= CMD_CALL_PROPAGATE_REPL;
    }
    call(c,call_flags);

     
    if (listLength(c->reply) == 0 && c->bufpos < PROTO_REPLY_CHUNK_BYTES) {
         
        c->buf[c->bufpos] = '\0';
        reply = c->buf;
        c->bufpos = 0;
    } else {
        reply = sdsnewlen(c->buf,c->bufpos);
        c->bufpos = 0;
        while(listLength(c->reply)) {
            clientReplyBlock *o = listNodeValue(listFirst(c->reply));

            reply = sdscatlen(reply,o->buf,o->used);
            listDelNode(c->reply,listFirst(c->reply));
        }
    }
    if (raise_error && reply[0] != '-') raise_error = 0;
    redisProtocolToLuaType(lua,reply);

     
    if (ldb.active && ldb.step)
        ldbLogRedisReply(reply);

     
    if ((cmd->flags & CMD_SORT_FOR_SCRIPT) &&
        (server.lua_replicate_commands == 0) &&
        (reply[0] == '*' && reply[1] != '-')) {
            luaSortArray(lua);
    }
    if (reply != c->buf) sdsfree(reply);
    c->reply_bytes = 0;

cleanup:
     
    for (j = 0; j < c->argc; j++) {
        robj *o = c->argv[j];

         
        if (j < LUA_CMD_OBJCACHE_SIZE &&
            o->refcount == 1 &&
            (o->encoding == OBJ_ENCODING_RAW ||
             o->encoding == OBJ_ENCODING_EMBSTR) &&
            sdslen(o->ptr) <= LUA_CMD_OBJCACHE_MAX_LEN)
        {
            sds s = o->ptr;
            if (cached_objects[j]) decrRefCount(cached_objects[j]);
            cached_objects[j] = o;
            cached_objects_len[j] = sdsalloc(s);
        } else {
            decrRefCount(o);
        }
    }

    if (c->argv != argv) {
        zfree(c->argv);
        argv = NULL;
        argv_size = 0;
    }

    c->user = NULL;

    if (raise_error) {
         
        inuse--;
        return luaRaiseError(lua);
    }
    inuse--;
    return 1;
}