wireproto: perform chunking and compression at protocol layer (API)
Currently, the "streamres" response type is populated with a generator
of chunks with compression possibly already applied. This puts the onus
on commands to perform chunking and compression. Architecturally, I
think this is the wrong place to perform this work. I think commands
should say "here is the data" and the protocol layer should take care
of encoding the final bytes to put on the wire.
Additionally, upcoming commits will improve wire protocol support for
compression. Having a central place for performing compression in the
protocol transport layer will be easier than having to deal with
compression at the commands layer.
This commit refactors the "streamres" response type to accept either
a generator or an object with "read." Additionally, the type now
accepts a flag indicating whether the response is a "version 1
compressible" response. This basically identifies all commands
currently performing compression. I could have used a special type
for this, but a flag works just as well. The argument name
foreshadows the introduction of wire protocol changes, hence the "v1."
The code for chunking and compressing has been moved to the output
generation function for each protocol transport. Some code has been
inlined, resulting in the deletion of now unused methods.
#
# Copyright 21 May 2005 - (c) 2005 Jake Edge <jake@edge2.net>
# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
import cgi
from .common import (
HTTP_OK,
)
from .. import (
util,
wireproto,
)
stringio = util.stringio
urlerr = util.urlerr
urlreq = util.urlreq
HGTYPE = 'application/mercurial-0.1'
HGERRTYPE = 'application/hg-error'
class webproto(wireproto.abstractserverproto):
def __init__(self, req, ui):
self.req = req
self.response = ''
self.ui = ui
def getargs(self, args):
knownargs = self._args()
data = {}
keys = args.split()
for k in keys:
if k == '*':
star = {}
for key in knownargs.keys():
if key != 'cmd' and key not in keys:
star[key] = knownargs[key][0]
data['*'] = star
else:
data[k] = knownargs[k][0]
return [data[k] for k in keys]
def _args(self):
args = self.req.form.copy()
postlen = int(self.req.env.get('HTTP_X_HGARGS_POST', 0))
if postlen:
args.update(cgi.parse_qs(
self.req.read(postlen), keep_blank_values=True))
return args
chunks = []
i = 1
while True:
h = self.req.env.get('HTTP_X_HGARG_' + str(i))
if h is None:
break
chunks += [h]
i += 1
args.update(cgi.parse_qs(''.join(chunks), keep_blank_values=True))
return args
def getfile(self, fp):
length = int(self.req.env['CONTENT_LENGTH'])
for s in util.filechunkiter(self.req, limit=length):
fp.write(s)
def redirect(self):
self.oldio = self.ui.fout, self.ui.ferr
self.ui.ferr = self.ui.fout = stringio()
def restore(self):
val = self.ui.fout.getvalue()
self.ui.ferr, self.ui.fout = self.oldio
return val
def compresschunks(self, chunks):
# Don't allow untrusted settings because disabling compression or
# setting a very high compression level could lead to flooding
# the server's network or CPU.
opts = {'level': self.ui.configint('server', 'zliblevel', -1)}
return util.compengines['zlib'].compressstream(chunks, opts)
def _client(self):
return 'remote:%s:%s:%s' % (
self.req.env.get('wsgi.url_scheme') or 'http',
urlreq.quote(self.req.env.get('REMOTE_HOST', '')),
urlreq.quote(self.req.env.get('REMOTE_USER', '')))
def iscmd(cmd):
return cmd in wireproto.commands
def call(repo, req, cmd):
p = webproto(req, repo.ui)
rsp = wireproto.dispatch(repo, p, cmd)
if isinstance(rsp, str):
req.respond(HTTP_OK, HGTYPE, body=rsp)
return []
elif isinstance(rsp, wireproto.streamres):
if rsp.reader:
gen = iter(lambda: rsp.reader.read(32768), '')
else:
gen = rsp.gen
if rsp.v1compressible:
gen = p.compresschunks(gen)
req.respond(HTTP_OK, HGTYPE)
return gen
elif isinstance(rsp, wireproto.pushres):
val = p.restore()
rsp = '%d\n%s' % (rsp.res, val)
req.respond(HTTP_OK, HGTYPE, body=rsp)
return []
elif isinstance(rsp, wireproto.pusherr):
# drain the incoming bundle
req.drain()
p.restore()
rsp = '0\n%s\n' % rsp.res
req.respond(HTTP_OK, HGTYPE, body=rsp)
return []
elif isinstance(rsp, wireproto.ooberror):
rsp = rsp.message
req.respond(HTTP_OK, HGERRTYPE, body=rsp)
return []