httppeer: use compression engine API for decompressing responses
In preparation for supporting multiple compression formats on the
wire protocol, we need all users of the wire protocol to use
compression engine APIs.
This commit ports the HTTP wire protocol client to use the
compression engine API.
The code for handling the HTTPException is a bit hacky. Essentially,
HTTPException could be thrown by any read() from the socket. However,
as part of porting the API, we no longer have a generator wrapping
the socket and we don't have a single place where we can trap the
exception. We solve this by introducing a proxy class that intercepts
read() and converts the exception appropriately.
In the future, we could introduce a new compression engine API that
supports emitting a generator of decompressed chunks. This would
eliminate the need for the proxy class. As I said when I introduced
the decompressorreader() API, I'm not fond of it and would support
transitioning to something better. This can be done as a follow-up,
preferably once all the code is using the compression engine API and
we have a better idea of the API needs of all the consumers.
# httppeer.py - HTTP repository proxy classes for mercurial
#
# Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>
# Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.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 errno
import os
import socket
import tempfile
from .i18n import _
from .node import nullid
from . import (
bundle2,
error,
httpconnection,
statichttprepo,
url,
util,
wireproto,
)
httplib = util.httplib
urlerr = util.urlerr
urlreq = util.urlreq
# FUTURE: consider refactoring this API to use generators. This will
# require a compression engine API to emit generators.
def decompressresponse(response, engine):
try:
reader = engine.decompressorreader(response)
except httplib.HTTPException:
raise IOError(None, _('connection ended unexpectedly'))
# We need to wrap reader.read() so HTTPException on subsequent
# reads is also converted.
origread = reader.read
class readerproxy(reader.__class__):
def read(self, *args, **kwargs):
try:
return origread(*args, **kwargs)
except httplib.HTTPException:
raise IOError(None, _('connection ended unexpectedly'))
reader.__class__ = readerproxy
return reader
class httppeer(wireproto.wirepeer):
def __init__(self, ui, path):
self.path = path
self.caps = None
self.handler = None
self.urlopener = None
self.requestbuilder = None
u = util.url(path)
if u.query or u.fragment:
raise error.Abort(_('unsupported URL component: "%s"') %
(u.query or u.fragment))
# urllib cannot handle URLs with embedded user or passwd
self._url, authinfo = u.authinfo()
self.ui = ui
self.ui.debug('using %s\n' % self._url)
self.urlopener = url.opener(ui, authinfo)
self.requestbuilder = urlreq.request
def __del__(self):
urlopener = getattr(self, 'urlopener', None)
if urlopener:
for h in urlopener.handlers:
h.close()
getattr(h, "close_all", lambda : None)()
def url(self):
return self.path
# look up capabilities only when needed
def _fetchcaps(self):
self.caps = set(self._call('capabilities').split())
def _capabilities(self):
if self.caps is None:
try:
self._fetchcaps()
except error.RepoError:
self.caps = set()
self.ui.debug('capabilities: %s\n' %
(' '.join(self.caps or ['none'])))
return self.caps
def lock(self):
raise error.Abort(_('operation not supported over http'))
def _callstream(self, cmd, _compressible=False, **args):
if cmd == 'pushkey':
args['data'] = ''
data = args.pop('data', None)
headers = args.pop('headers', {})
self.ui.debug("sending %s command\n" % cmd)
q = [('cmd', cmd)]
headersize = 0
# Important: don't use self.capable() here or else you end up
# with infinite recursion when trying to look up capabilities
# for the first time.
postargsok = self.caps is not None and 'httppostargs' in self.caps
# TODO: support for httppostargs when data is a file-like
# object rather than a basestring
canmungedata = not data or isinstance(data, basestring)
if postargsok and canmungedata:
strargs = urlreq.urlencode(sorted(args.items()))
if strargs:
if not data:
data = strargs
elif isinstance(data, basestring):
data = strargs + data
headers['X-HgArgs-Post'] = len(strargs)
else:
if len(args) > 0:
httpheader = self.capable('httpheader')
if httpheader:
headersize = int(httpheader.split(',', 1)[0])
if headersize > 0:
# The headers can typically carry more data than the URL.
encargs = urlreq.urlencode(sorted(args.items()))
headerfmt = 'X-HgArg-%s'
contentlen = headersize - len(headerfmt % '000' + ': \r\n')
headernum = 0
varyheaders = []
for i in xrange(0, len(encargs), contentlen):
headernum += 1
header = headerfmt % str(headernum)
headers[header] = encargs[i:i + contentlen]
varyheaders.append(header)
headers['Vary'] = ','.join(varyheaders)
else:
q += sorted(args.items())
qs = '?%s' % urlreq.urlencode(q)
cu = "%s%s" % (self._url, qs)
size = 0
if util.safehasattr(data, 'length'):
size = data.length
elif data is not None:
size = len(data)
if size and self.ui.configbool('ui', 'usehttp2', False):
headers['Expect'] = '100-Continue'
headers['X-HgHttp2'] = '1'
if data is not None and 'Content-Type' not in headers:
headers['Content-Type'] = 'application/mercurial-0.1'
req = self.requestbuilder(cu, data, headers)
if data is not None:
self.ui.debug("sending %s bytes\n" % size)
req.add_unredirected_header('Content-Length', '%d' % size)
try:
resp = self.urlopener.open(req)
except urlerr.httperror as inst:
if inst.code == 401:
raise error.Abort(_('authorization failed'))
raise
except httplib.HTTPException as inst:
self.ui.debug('http error while sending %s command\n' % cmd)
self.ui.traceback()
raise IOError(None, inst)
except IndexError:
# this only happens with Python 2.3, later versions raise URLError
raise error.Abort(_('http error, possibly caused by proxy setting'))
# record the url we got redirected to
resp_url = resp.geturl()
if resp_url.endswith(qs):
resp_url = resp_url[:-len(qs)]
if self._url.rstrip('/') != resp_url.rstrip('/'):
if not self.ui.quiet:
self.ui.warn(_('real URL is %s\n') % resp_url)
self._url = resp_url
try:
proto = resp.getheader('content-type')
except AttributeError:
proto = resp.headers.get('content-type', '')
safeurl = util.hidepassword(self._url)
if proto.startswith('application/hg-error'):
raise error.OutOfBandError(resp.read())
# accept old "text/plain" and "application/hg-changegroup" for now
if not (proto.startswith('application/mercurial-') or
(proto.startswith('text/plain')
and not resp.headers.get('content-length')) or
proto.startswith('application/hg-changegroup')):
self.ui.debug("requested URL: '%s'\n" % util.hidepassword(cu))
raise error.RepoError(
_("'%s' does not appear to be an hg repository:\n"
"---%%<--- (%s)\n%s\n---%%<---\n")
% (safeurl, proto or 'no content-type', resp.read(1024)))
if proto.startswith('application/mercurial-'):
try:
version = proto.split('-', 1)[1]
version_info = tuple([int(n) for n in version.split('.')])
except ValueError:
raise error.RepoError(_("'%s' sent a broken Content-Type "
"header (%s)") % (safeurl, proto))
if version_info > (0, 1):
raise error.RepoError(_("'%s' uses newer protocol %s") %
(safeurl, version))
if _compressible:
return decompressresponse(resp, util.compengines['zlib'])
return resp
def _call(self, cmd, **args):
fp = self._callstream(cmd, **args)
try:
return fp.read()
finally:
# if using keepalive, allow connection to be reused
fp.close()
def _callpush(self, cmd, cg, **args):
# have to stream bundle to a temp file because we do not have
# http 1.1 chunked transfer.
types = self.capable('unbundle')
try:
types = types.split(',')
except AttributeError:
# servers older than d1b16a746db6 will send 'unbundle' as a
# boolean capability. They only support headerless/uncompressed
# bundles.
types = [""]
for x in types:
if x in bundle2.bundletypes:
type = x
break
tempname = bundle2.writebundle(self.ui, cg, None, type)
fp = httpconnection.httpsendfile(self.ui, tempname, "rb")
headers = {'Content-Type': 'application/mercurial-0.1'}
try:
r = self._call(cmd, data=fp, headers=headers, **args)
vals = r.split('\n', 1)
if len(vals) < 2:
raise error.ResponseError(_("unexpected response:"), r)
return vals
except socket.error as err:
if err.args[0] in (errno.ECONNRESET, errno.EPIPE):
raise error.Abort(_('push failed: %s') % err.args[1])
raise error.Abort(err.args[1])
finally:
fp.close()
os.unlink(tempname)
def _calltwowaystream(self, cmd, fp, **args):
fh = None
fp_ = None
filename = None
try:
# dump bundle to disk
fd, filename = tempfile.mkstemp(prefix="hg-bundle-", suffix=".hg")
fh = os.fdopen(fd, "wb")
d = fp.read(4096)
while d:
fh.write(d)
d = fp.read(4096)
fh.close()
# start http push
fp_ = httpconnection.httpsendfile(self.ui, filename, "rb")
headers = {'Content-Type': 'application/mercurial-0.1'}
return self._callstream(cmd, data=fp_, headers=headers, **args)
finally:
if fp_ is not None:
fp_.close()
if fh is not None:
fh.close()
os.unlink(filename)
def _callcompressable(self, cmd, **args):
return self._callstream(cmd, _compressible=True, **args)
def _abort(self, exception):
raise exception
class httpspeer(httppeer):
def __init__(self, ui, path):
if not url.has_https:
raise error.Abort(_('Python support for SSL and HTTPS '
'is not installed'))
httppeer.__init__(self, ui, path)
def instance(ui, path, create):
if create:
raise error.Abort(_('cannot create new http repository'))
try:
if path.startswith('https:'):
inst = httpspeer(ui, path)
else:
inst = httppeer(ui, path)
try:
# Try to do useful work when checking compatibility.
# Usually saves a roundtrip since we want the caps anyway.
inst._fetchcaps()
except error.RepoError:
# No luck, try older compatibility check.
inst.between([(nullid, nullid)])
return inst
except error.RepoError as httpexception:
try:
r = statichttprepo.instance(ui, "static-" + path, create)
ui.note(_('(falling back to static-http)\n'))
return r
except error.RepoError:
raise httpexception # use the original http RepoError instead