view mercurial/lock.py @ 405:99470ae6b424

Check if repository exists

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Check if repository exists

From: Goffredo Baroncelli <[e-mail]>
Subject: Re: Trivial: in remoterepository.__init__ check if the repository
        exist

I hope that this is correct :-)

Another typo, another patch, tank to Peter Stamfest and Radoslaw Szkodzinski.

The patch is trivial: adds a check in the body of the init method of the
+remoterepository
class. Before if the path didn't exist, hg would not raise any error.

Test manually performed after the patch has been merged:

test:                                                     result
create a new repository from another local repository     OK ( no problem )
create an empty repository                                OK ( no problem )
pull from a not existent repositary                       OK ( raise an error )

(error message tweaked by mpm)

manifest hash: ac7f625a8d87c693b61718b9fc5604d28b882bbd
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.0 (GNU/Linux)

iD8DBQFCuM0gywK+sNU5EO8RAsnGAJ42HE3m01tlGqrIR3GVfuhvCjEJkgCfffvp
bEhfvjaiAdBV50HMULq8N00=
=QDHW
-----END PGP SIGNATURE-----

# lock.py - simple locking scheme for mercurial
#
# Copyright 2005 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.

import os, time

class LockHeld(Exception):
    pass

class lock:
    def __init__(self, file, wait = 1):
        self.f = file
        self.held = 0
        self.wait = wait
        self.lock()

    def __del__(self):
        self.release()

    def lock(self):
        while 1:
            try:
                self.trylock()
                return 1
            except LockHeld, inst:
                if self.wait:
                    time.sleep(1)
                    continue
                raise inst
        
    def trylock(self):
        pid = os.getpid()
        try:
            os.symlink(str(pid), self.f)
            self.held = 1
        except:
            raise LockHeld(os.readlink(self.f))

    def release(self):
        if self.held:
            self.held = 0
            os.unlink(self.f)