mercurial/httprangereader.py

localrepository.status: only acquire wlock if actually needed.

This speeds up the common case of not needing to update the dirstate,
and avoids the need to reload and parse the dirstate "just in case".

# httprangereader.py - just what it says
#
# Copyright 2005, 2006 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 - 1
        req.add_header('Range', 'bytes=%d-%s' % (self.pos, end))
        f = urllib2.urlopen(req)
        data = f.read()
        if bytes:
            data = data[:bytes]
        return data