Re: [Gnu-arch-users] Re: Questions from a Subversion user

[Tom Lord]

    > From: John Goerzen <address@hidden>

    > > arch supports a bunch of transports: ftp, sftp, http, and others.  arch
    > > implements its own locking scheme.  I am not sure what you mean by
    > > "insure integrity."

    > What I'm talking about is multiple users writing to the repository at
    > once.  FTP (and SFTP, and HTTP) doesn't implement anything like
    > flock() -- and the best that one normally can do is creating
    > lockfiles, which have inherent race conditions and are thus
    > unreliable.  It'd be really easy to have two people running a STOR on
    > the same file at once -- with likely disastrous results.

The locking mechnanisms in arch do not have race conditions and are
robust for multi-user concurrent access.   They rely only on some
least-common-denominator properties of `mkdir' and `rename' -- safe,
even, on NFS.

-t