Article Caching
===============

   If you have an *extremely* slow NNTP connection, you may consider
turning article caching on.  Each article will then be stored locally
under your home directory.  As you may surmise, this could potentially
use *huge* amounts of disk space, as well as eat up all your inodes so
fast it will make your head swim.  In vodka.

   Used carefully, though, it could be just an easier way to save
articles.

   To turn caching on, set `gnus-use-cache' to `t'.  By default, all
articles that are ticked or marked as dormant will then be copied over
to your local cache (`gnus-cache-directory').  Whether this cache is
flat or hierarchal is controlled by the `gnus-use-long-file-name'
variable, as usual.

   When re-select a ticked or dormant article, it will be fetched from
the cache instead of from the server.  As articles in your cache will
never expire, this might serve as a method of saving articles while
still keeping them where they belong.  Just mark all articles you want
to save as dormant, and don't worry.

   When an article is marked as read, is it removed from the cache.

   The entering/removal of articles from the cache is controlled by the
`gnus-cache-enter-articles' and `gnus-cache-remove-articles' variables.
Both are lists of symbols.  The first is `(ticked dormant)' by
default, meaning that ticked and dormant articles will be put in the
cache.  The latter is `(read)' by default, meaning that articles that
are marked as read are removed from the cache.  Possibly symbols in
these two lists are `ticked', `dormant', `unread' and `read'.

   So where does the massive article-fetching and storing come into the
picture?  The `gnus-jog-cache' command will go through all subscribed
newsgroups, request all unread articles, and store them in the cache.
You should only ever, ever ever ever, use this command if 1) your
connection to the NNTP server is really, really, really slow and 2) you
have a really, really, really huge disk.  Seriously.

   It is likely that you do not want caching on some groups.  For
instance, if your `nnml' mail is located under your home directory, it
makes no sense to cache it somewhere else under your home directory.
Unless you feel that it's neat to use twice as much space.  To limit
the caching, you could set the `gnus-uncacheable-groups' regexp to
`^nnml', for instance.  This variable is `nil' by default.

   The cache stores information on what articles it contains in its
active file (`gnus-cache-active-file').  If this file (or any other
parts of the cache) becomes all messed up for some reason or other, Gnus
offers two functions that will try to set things right.  `M-x
gnus-cache-generate-nov-databases' will (re)build all the NOV files,
and `gnus-cache-generate-active' will (re)generate the active file.