Protocol switch from using generators to stream-like objects.
This allows the the pull side to precisely control how much data is
read so that another encapsulation layer is not needed.
An http client gets a response with a finite size. Because ssh clients
need to keep the stream open, we must not read more data than is sent
in a response. But due to the streaming nature of the changegroup
scheme, only the piece that's parsing the data knows how far it's
allowed to read.
This means the generator scheme isn't fine-grained enough. Instead we
need file-like objects with a read(x) method. This switches everything
for push/pull over to using file-like objects rather than generators.
# httprangereader.py - just what it says
#
# Copyright 2005 Matt Mackall <mpm@selenic.com>
#
# 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:
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()