view mercurial/httprangereader.py @ 1877:d314a89fa4f1

change lock format to let us detect and break stale locks.

old style: symlink to pid
new style: symlink to hostname:pid

if lock code finds new-style lock, it breaks lock if locking pid is on
same machine and pid is not alive.

otherwise, lock is left alone.  this makes locking code safe with
old-style locks and with locks on other machines.

new code makes server part of mercurial more robust in case machine
crashes, power fails, or crazy user does kill -9.

# httprangereader.py - just what it says
#
# 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 byterange, urllib2

class httprangereader(object):
    def __init__(self, url):
        self.url = url
        self.pos = 0
    def seek(self, pos):
        self.pos = pos
    def read(self, bytes=None):
        opener = urllib2.build_opener(byterange.HTTPRangeHandler())
        urllib2.install_opener(opener)
        req = urllib2.Request(self.url)
        end = ''
        if bytes: end = self.pos + bytes
        req.add_header('Range', 'bytes=%d-%s' % (self.pos, end))
        f = urllib2.urlopen(req)
        return f.read()