Delivery-Date: Fri Nov 21 20:36:22 2008
Message-Id: <200811220434.mAM4Y5Zv005614@bourbon.usc.edu>
To: cs551@merlot.usc.edu
Subject: Re: Doubt regarding file storages
Date: Fri, 21 Nov 2008 20:34:05 -0800
From: Bill Cheng <william@bourbon.usc.edu>

Someone wrote:

  > I have a few questions regarding the storage of files:
  > 
  > 1) Whenever a store is given, we store the files in the mini-filesystem as
  > #.meta and #.data. These files are called the "cached" files right ?

You need to follow the rules to determine if they are in the
cache or in permanent storage.  We have many many postings
talking about this issue.

  > In the
  > single beacon node case, should we "always" store the file or is it also
  > dependent on the "StoreProb" ?

Please just following the protocol!  If the protocol doesn't
say anything about if a node is a beacon node, then it applies
to all nodes.

  > 2) Suppose the user enters "get 3" and it turns out that the filename is
  > "chess.jpg". This has to be stored in the CWD right ?

Please see my message with timestamp "Wed 19 Nov 10:05".

  > 3) Also, its mentioned in the spec that if the file "chess.jpg" already
  > exists, we must ask the user if he wants to replace it. Now what would
  > happen if this newer version of chess.jpg we want to store is actually a
  > different file with a different "sha1" value. Should we still over write it
  > and store it in our CWD anyway ?

If the user says yes, you should overwrite it.  (If you want
to help the user out by providing more information, you can
print the old filesize and new filesize.  But this is not
required.)
--
Bill Cheng // bill.cheng@usc.edu <URL:http://merlot.usc.edu/william/usc/>