view mercurial/lock.py @ 611:48c3eb2bf844

* clean up error handling when user requests to use a non file object
# HG changeset patch
# User [e-mail]
# Node ID 1ae21732349f5b6dba2941609a044d9c365a6fb2
# Parent  94744f6fe0e7c19b10fab7eb24249f3eeaa5489a
* clean up error handling when user requests to use a non file object
  - use os.path.exists() to verify the item exists
  - use os.path.isfile() to check whether the item is a file or not

diff -r 94744f6fe0e7 -r 1ae21732349f mercurial/hg.py

# 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
import util

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:
            util.makelock(str(pid), self.f)
            self.held = 1
        except:
            raise LockHeld(util.readlock(self.f))

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