range locks vs. section locks

I agree with Larry that it makes more sense in most cases to talk about
section locks for the scenario of multiple authors wanting to manipulate
different parts of the document. If your locks are on byte ranges, then the
semantics (as I understand them) seem pretty unpleasant:

1. In the simplest approach, you can't change the size of the locked range
unless you lock from the start of the range to the end of the document
(thus effectively locking most of the document if what you're modifying is
near the beginning of the document).

2. In a more complex approach, you can't safely re-lock a range using the
same start & end points once you release the lock, because the actual byte
numbering of that content in the document may have changed as others have
inserted or deleted bytes from their ranges.  Section locking also has this
problem, but in a milder form: the problem arises as sections are added and
removed, which one would expect to be much less common than adding and
removing bytes.

People who have more experience with byte-locking systems should feel free
to correct me on these points if I have misunderstood.

--Mark

Received on Friday, 21 February 1997 12:00:41 UTC