view mercurial/httprangereader.py @ 2138:f5046cab9e2e

Fix revlog-ng interaction with old-http.

revlog.py wasn't trying to detect the version of a revlog file that
doesn't exist on the filesystem (as is the case with old-http).

Additionally, there was an off-by-one error in httprangereader.read
(ranges in HTTP Range headers are inclusive), making it get more data
than what was asked for.  This made a struct.unpack complain that
"unpack str size does not match format".

Finally, with the two fixes above, test-static-http fails, since
BaseHTTPServer doesn't understand ranges and returns too much data.
Work around that by reading only the specified amount.

# 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 - 1
        req.add_header('Range', 'bytes=%d-%s' % (self.pos, end))
        f = urllib2.urlopen(req)
        return f.read(bytes)