Re: [PATCH v3] Allow applying filters to summary consecutively

[Richard Stallman <rms@gnu.org>]

[[[ To any NSA and FBI agents reading my email: please consider    ]]]
[[[ whether defending the US Constitution against all enemies,     ]]]
[[[ foreign or domestic, requires you to follow Snowden's example. ]]]

  > 1. Mbox files do not scale.  It is not uncommon to have mail folders that 
  > are several Gb large, and opening a 50 Kb email in say a 2 Gb folder means 
  > reading the whole 2 Gb file.

Even my RMAIL file is not a whole GB in size.

How does a mail agent find a specific message in a maildir?
Does it have to read thousands of files one by one?

  > 2. Mbox files are fragile.  If for whatever reason a program crashes while 
  > updating an mbox file, the whole mbox file can be corrupted, or even lost.

Rmail does not have that problem.  Emacs writes the new file under
another name, then renames it into place.  That is atomic.

  > 3. Mbox files are slow.  For example, when an email in the middle of a 
  > mail folder is deleted, or moved to another mail folder, the whole mbox 
  > file must be written again.

Rmail does not try to save the mbox every time you change it.  It
saves when you say to save.  For my 300 meg Rmail file, that is
not painful.

  > 4. Mbox files cannot be accessed concurrently by two programs, e.g. the 
  > mail delivery agent and the mail user agent, or two mail user agents.

That is the case for the incoming mbox.  We have interlocking for
that.  Also, you don't ever leave the mail in the incoming mbox.  You
copy it into the RMAIL file.

What it comes down to is that your mail user agant is designed to be
convenient and easy with maildirs, and Rmail is designed to be
convenient and easy with mboxes.  If you suppose that Rmail works
like a user agent that was designed for maildirs, you will expect
some operations to be problematical, which in fact are not.



-- 
Dr Richard Stallman (https://stallman.org)
Chief GNUisance of the GNU Project (https://gnu.org)
Founder, Free Software Foundation (https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)