redis/TODO

Redis TODO
----------

WARNING: are you a possible Redis contributor?
         Before implementing what is listed what is listed in this file
         please drop a message in the Redis google group or chat with
         antirez or pietern on irc.freenode.org #redis to check if the work
         is already in progress and if the feature is still interesting for
         us, and *how* exactly this can be implemented to have good changes
         of a merge. Otherwise it is probably wasted work! Thank you

DISKSTORE TODO
==============

* Check that 00/00 and ff/ff exist at startup, otherwise exit with error.
* Implement sync flush option, where data is written synchronously on disk when a command is executed.
* Implement MULTI/EXEC as transaction abstract API to diskstore.c, with transaction_start, transaction_end, and a journal to recover.
* Stop BGSAVE thread on shutdown and any other condition where the child is killed during normal bgsave.
* Use a mutex to log on the file, so that we don't get overlapping messages, or even better make sure to use a single write against it.

REPLICATION
===========

* PING between master and slave from time to time, so we can subject the
master-slave link to timeout, and detect when the connection is gone even
if the socket is still up.

OPTIMIZATIONS
=============

* SORT: Don't copy the list into a vector when BY argument is constant.
* Write the hash table size of every db in the dump, so that Redis can resize the hash table just one time when loading a big DB.
* Read-only mode for slaves.

KNOWN BUGS
==========

* What happens in the following scenario:
    1) We are reading an AOF file.
    2) SETEX FOO 5 BAR
    3) APPEND FOO ZAP
    What happens if between 1 and 2 for some reason (system under huge load
    or alike) too many time passes? We should prevent expires while the
    AOF is loading.