Request for review of new redis-fdw module

My redis-fdw implementation supports read and write to the Redis backend, so you can do insert, update, and delete. e.g. you can define a hash table as:

) server redserver options(tabletype 'hash');

and do:
  select * from rhash where key = 'foo' and field = 'bar';

  update rhash set value = 'bahbah' where key = 'foo' and field = 'bar';
  delete from rhash where key = 'foo' and field = 'bar';

I need someone experienced with postgresql's internals for FDWs to review my code and let me know if I've done something wrong or where I can optimize it a little more. Once it has been reviewed, I'll post it up and announce it on my github account for public consumption. But for now I want to make sure that the code is correct.

There are some functions (Explain* and costs) which I know I haven't implemented properly so assistance with that is also appreciated.

Please email me if you can assist with reviewing.

thanks
Leon