Function processCommand

src/server.cpp:4789–5129

If this function gets called we already read a whole * command, arguments are in the client argv/argc fields. * processCommand() execute the command or prepare the * server for a bulk read from the client. * * If C_OK is returned the client is still alive and valid and * other operations can be performed by the caller. Otherwise * if C_ERR is returned the client was destroyed (i.e. after QU

 * other operations can be performed by the caller. Otherwise
 * if C_ERR is returned the client was destroyed (i.e. after QUIT). */
int processCommand(client *c, int callFlags) {
    AssertCorrectThread(c);
    serverAssert((callFlags & CMD_CALL_ASYNC) || GlobalLocksAcquired());
    if (!g_pserver->lua_timedout) {
        /* Both EXEC and EVAL call call() directly so there should be
         * no way in_exec or in_eval or propagate_in_transaction is 1.
         * That is unless lua_timedout, in which case client may run
         * some commands. Also possible that some other thread set
         * propagate_in_transaction if this is an async command. */
        serverAssert(!serverTL->propagate_in_transaction);
        serverAssert(!serverTL->in_exec);
        serverAssert(!serverTL->in_eval);
    }

    if (moduleHasCommandFilters())
    {
        moduleCallCommandFilters(c);
    }

    /* The QUIT command is handled separately. Normal command procs will
     * go through checking for replication and QUIT will cause trouble
     * when FORCE_REPLICATION is enabled and would be implemented in
     * a regular command proc. */
    if (!strcasecmp((const char*)ptrFromObj(c->argv[0]),"quit")) {
        addReply(c,shared.ok);
        c->flags |= CLIENT_CLOSE_AFTER_REPLY;
        return C_ERR;
    }

    /* Now lookup the command and check ASAP about trivial error conditions
     * such as wrong arity, bad command name and so forth. */
    c->cmd = c->lastcmd = lookupCommand((sds)ptrFromObj(c->argv[0]));
    if (!c->cmd) {
        sds args = sdsempty();
        int i;
        for (i=1; i < c->argc && sdslen(args) < 128; i++)
            args = sdscatprintf(args, "`%.*s`, ", 128-(int)sdslen(args), (char*)ptrFromObj(c->argv[i]));
        rejectCommandFormat(c,"unknown command `%s`, with args beginning with: %s",
            (char*)ptrFromObj(c->argv[0]), args);
        sdsfree(args);
        return C_OK;
    } else if ((c->cmd->arity > 0 && c->cmd->arity != c->argc) ||
               (c->argc < -c->cmd->arity)) {
        rejectCommandFormat(c,"wrong number of arguments for '%s' command",
            c->cmd->name);
        return C_OK;
    }

    int is_read_command = (c->cmd->flags & CMD_READONLY) ||
                           (c->cmd->proc == execCommand && (c->mstate.cmd_flags & CMD_READONLY));
    int is_write_command = (c->cmd->flags & CMD_WRITE) ||
                           (c->cmd->proc == execCommand && (c->mstate.cmd_flags & CMD_WRITE));
    int is_denyoom_command = (c->cmd->flags & CMD_DENYOOM) ||
                             (c->cmd->proc == execCommand && (c->mstate.cmd_flags & CMD_DENYOOM));
    int is_denystale_command = !(c->cmd->flags & CMD_STALE) ||
                               (c->cmd->proc == execCommand && (c->mstate.cmd_inv_flags & CMD_STALE));
    int is_denyloading_command = !(c->cmd->flags & CMD_LOADING) ||
                                 (c->cmd->proc == execCommand && (c->mstate.cmd_inv_flags & CMD_LOADING));