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# client.py -- Implementation of the server side git protocols
# Copyright (C) 2008-2009 Jelmer Vernooij <jelmer@samba.org>
# Copyright (C) 2008 John Carr
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# or (at your option) a later version of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
# MA 02110-1301, USA.
"""Client side support for the Git protocol.
The Dulwich client supports the following capabilities:
* thin-pack
* multi_ack_detailed
* multi_ack
* side-band-64k
* ofs-delta
* report-status
* delete-refs
Known capabilities that are not supported:
* shallow
* no-progress
* include-tag
"""
__docformat__ = 'restructuredText'
from cStringIO import StringIO
import select
import socket
import subprocess
import urllib2
import urlparse
from dulwich.errors import (
GitProtocolError,
NotGitRepository,
SendPackError,
UpdateRefsError,
)
from dulwich.protocol import (
_RBUFSIZE,
PktLineParser,
Protocol,
TCP_GIT_PORT,
ZERO_SHA,
extract_capabilities,
)
from dulwich.pack import (
write_pack_objects,
)
# Python 2.6.6 included these in urlparse.uses_netloc upstream. Do
# monkeypatching to enable similar behaviour in earlier Pythons:
for scheme in ('git', 'git+ssh'):
if scheme not in urlparse.uses_netloc:
urlparse.uses_netloc.append(scheme)
def _fileno_can_read(fileno):
"""Check if a file descriptor is readable."""
return len(select.select([fileno], [], [], 0)[0]) > 0
COMMON_CAPABILITIES = ['ofs-delta', 'side-band-64k']
FETCH_CAPABILITIES = ['multi_ack', 'multi_ack_detailed'] + COMMON_CAPABILITIES
SEND_CAPABILITIES = ['report-status'] + COMMON_CAPABILITIES
class ReportStatusParser(object):
"""Handle status as reported by servers with the 'report-status' capability.
"""
def __init__(self):
self._done = False
self._pack_status = None
self._ref_status_ok = True
self._ref_statuses = []
def check(self):
"""Check if there were any errors and, if so, raise exceptions.
:raise SendPackError: Raised when the server could not unpack
:raise UpdateRefsError: Raised when refs could not be updated
"""
if self._pack_status not in ('unpack ok', None):
raise SendPackError(self._pack_status)
if not self._ref_status_ok:
ref_status = {}
ok = set()
for status in self._ref_statuses:
if ' ' not in status:
# malformed response, move on to the next one
continue
status, ref = status.split(' ', 1)
if status == 'ng':
if ' ' in ref:
ref, status = ref.split(' ', 1)
else:
ok.add(ref)
ref_status[ref] = status
raise UpdateRefsError('%s failed to update' %
', '.join([ref for ref in ref_status
if ref not in ok]),
ref_status=ref_status)
def handle_packet(self, pkt):
"""Handle a packet.
:raise GitProtocolError: Raised when packets are received after a
flush packet.
"""
if self._done:
raise GitProtocolError("received more data after status report")
if pkt is None:
self._done = True
return
if self._pack_status is None:
self._pack_status = pkt.strip()
else:
ref_status = pkt.strip()
self._ref_statuses.append(ref_status)
if not ref_status.startswith('ok '):
self._ref_status_ok = False
# TODO(durin42): this doesn't correctly degrade if the server doesn't
# support some capabilities. This should work properly with servers
# that don't support multi_ack.
class GitClient(object):
"""Git smart server client.
"""
def __init__(self, thin_packs=True, report_activity=None):
"""Create a new GitClient instance.
:param thin_packs: Whether or not thin packs should be retrieved
:param report_activity: Optional callback for reporting transport
activity.
"""
self._report_activity = report_activity
self._fetch_capabilities = set(FETCH_CAPABILITIES)
self._send_capabilities = set(SEND_CAPABILITIES)
if thin_packs:
self._fetch_capabilities.add('thin-pack')
def _read_refs(self, proto):
server_capabilities = None
refs = {}
# Receive refs from server
for pkt in proto.read_pkt_seq():
(sha, ref) = pkt.rstrip('\n').split(' ', 1)
if sha == 'ERR':
raise GitProtocolError(ref)
if server_capabilities is None:
(ref, server_capabilities) = extract_capabilities(ref)
refs[ref] = sha
return refs, set(server_capabilities)
def send_pack(self, path, determine_wants, generate_pack_contents,
progress=None):
"""Upload a pack to a remote repository.
:param path: Repository path
:param generate_pack_contents: Function that can return a sequence of the
shas of the objects to upload.
:param progress: Optional progress function
:raises SendPackError: if server rejects the pack data
:raises UpdateRefsError: if the server supports report-status
and rejects ref updates
"""
raise NotImplementedError(self.send_pack)
def fetch(self, path, target, determine_wants=None, progress=None):
"""Fetch into a target repository.
:param path: Path to fetch from
:param target: Target repository to fetch into
:param determine_wants: Optional function to determine what refs
to fetch
:param progress: Optional progress function
:return: remote refs as dictionary
"""
if determine_wants is None:
determine_wants = target.object_store.determine_wants_all
f, commit = target.object_store.add_pack()
try:
return self.fetch_pack(path, determine_wants,
target.get_graph_walker(), f.write, progress)
finally:
commit()
def fetch_pack(self, path, determine_wants, graph_walker, pack_data,
progress=None):
"""Retrieve a pack from a git smart server.
:param determine_wants: Callback that returns list of commits to fetch
:param graph_walker: Object with next() and ack().
:param pack_data: Callback called for each bit of data in the pack
:param progress: Callback for progress reports (strings)
"""
raise NotImplementedError(self.fetch_pack)
def _parse_status_report(self, proto):
unpack = proto.read_pkt_line().strip()
if unpack != 'unpack ok':
st = True
# flush remaining error data
while st is not None:
st = proto.read_pkt_line()
raise SendPackError(unpack)
statuses = []
errs = False
ref_status = proto.read_pkt_line()
while ref_status:
ref_status = ref_status.strip()
statuses.append(ref_status)
if not ref_status.startswith('ok '):
errs = True
ref_status = proto.read_pkt_line()
if errs:
ref_status = {}
ok = set()
for status in statuses:
if ' ' not in status:
# malformed response, move on to the next one
continue
status, ref = status.split(' ', 1)
if status == 'ng':
if ' ' in ref:
ref, status = ref.split(' ', 1)
else:
ok.add(ref)
ref_status[ref] = status
raise UpdateRefsError('%s failed to update' %
', '.join([ref for ref in ref_status
if ref not in ok]),
ref_status=ref_status)
def _read_side_band64k_data(self, proto, channel_callbacks):
"""Read per-channel data.
This requires the side-band-64k capability.
:param proto: Protocol object to read from
:param channel_callbacks: Dictionary mapping channels to packet
handlers to use. None for a callback discards channel data.
"""
for pkt in proto.read_pkt_seq():
channel = ord(pkt[0])
pkt = pkt[1:]
try:
cb = channel_callbacks[channel]
except KeyError:
raise AssertionError('Invalid sideband channel %d' % channel)
else:
if cb is not None:
cb(pkt)
def _handle_receive_pack_head(self, proto, capabilities, old_refs, new_refs):
"""Handle the head of a 'git-receive-pack' request.
:param proto: Protocol object to read from
:param capabilities: List of negotiated capabilities
:param old_refs: Old refs, as received from the server
:param new_refs: New refs
:return: (have, want) tuple
"""
want = []
have = [x for x in old_refs.values() if not x == ZERO_SHA]
sent_capabilities = False
for refname in set(new_refs.keys() + old_refs.keys()):
old_sha1 = old_refs.get(refname, ZERO_SHA)
new_sha1 = new_refs.get(refname, ZERO_SHA)
if old_sha1 != new_sha1:
if sent_capabilities:
proto.write_pkt_line('%s %s %s' % (old_sha1, new_sha1,
refname))
else:
proto.write_pkt_line(
'%s %s %s\0%s' % (old_sha1, new_sha1, refname,
' '.join(capabilities)))
sent_capabilities = True
if new_sha1 not in have and new_sha1 != ZERO_SHA:
want.append(new_sha1)
proto.write_pkt_line(None)
return (have, want)
def _handle_receive_pack_tail(self, proto, capabilities, progress=None):
"""Handle the tail of a 'git-receive-pack' request.
:param proto: Protocol object to read from
:param capabilities: List of negotiated capabilities
:param progress: Optional progress reporting function
"""
if 'report-status' in capabilities:
report_status_parser = ReportStatusParser()
else:
report_status_parser = None
if "side-band-64k" in capabilities:
if progress is None:
progress = lambda x: None
channel_callbacks = { 2: progress }
if 'report-status' in capabilities:
channel_callbacks[1] = PktLineParser(
report_status_parser.handle_packet).parse
self._read_side_band64k_data(proto, channel_callbacks)
else:
if 'report-status' in capabilities:
for pkt in proto.read_pkt_seq():
report_status_parser.handle_packet(pkt)
if report_status_parser is not None:
report_status_parser.check()
# wait for EOF before returning
data = proto.read()
if data:
raise SendPackError('Unexpected response %r' % data)
def _handle_upload_pack_head(self, proto, capabilities, graph_walker,
wants, can_read):
"""Handle the head of a 'git-upload-pack' request.
:param proto: Protocol object to read from
:param capabilities: List of negotiated capabilities
:param graph_walker: GraphWalker instance to call .ack() on
:param wants: List of commits to fetch
:param can_read: function that returns a boolean that indicates
whether there is extra graph data to read on proto
"""
assert isinstance(wants, list) and type(wants[0]) == str
proto.write_pkt_line('want %s %s\n' % (
wants[0], ' '.join(capabilities)))
for want in wants[1:]:
proto.write_pkt_line('want %s\n' % want)
proto.write_pkt_line(None)
have = graph_walker.next()
while have:
proto.write_pkt_line('have %s\n' % have)
if can_read():
pkt = proto.read_pkt_line()
parts = pkt.rstrip('\n').split(' ')
if parts[0] == 'ACK':
graph_walker.ack(parts[1])
if parts[2] in ('continue', 'common'):
pass
elif parts[2] == 'ready':
break
else:
raise AssertionError(
"%s not in ('continue', 'ready', 'common)" %
parts[2])
have = graph_walker.next()
proto.write_pkt_line('done\n')
def _handle_upload_pack_tail(self, proto, capabilities, graph_walker,
pack_data, progress=None, rbufsize=_RBUFSIZE):
"""Handle the tail of a 'git-upload-pack' request.
:param proto: Protocol object to read from
:param capabilities: List of negotiated capabilities
:param graph_walker: GraphWalker instance to call .ack() on
:param pack_data: Function to call with pack data
:param progress: Optional progress reporting function
:param rbufsize: Read buffer size
"""
pkt = proto.read_pkt_line()
while pkt:
parts = pkt.rstrip('\n').split(' ')
if parts[0] == 'ACK':
graph_walker.ack(pkt.split(' ')[1])
if len(parts) < 3 or parts[2] not in (
'ready', 'continue', 'common'):
break
pkt = proto.read_pkt_line()
if "side-band-64k" in capabilities:
if progress is None:
# Just ignore progress data
progress = lambda x: None
self._read_side_band64k_data(proto, {1: pack_data, 2: progress})
# wait for EOF before returning
data = proto.read()
if data:
raise Exception('Unexpected response %r' % data)
else:
while True:
data = self.read(rbufsize)
if data == "":
break
pack_data(data)
class TraditionalGitClient(GitClient):
"""Traditional Git client."""
def _connect(self, cmd, path):
"""Create a connection to the server.
This method is abstract - concrete implementations should
implement their own variant which connects to the server and
returns an initialized Protocol object with the service ready
for use and a can_read function which may be used to see if
reads would block.
:param cmd: The git service name to which we should connect.
:param path: The path we should pass to the service.
"""
raise NotImplementedError()
def send_pack(self, path, determine_wants, generate_pack_contents,
progress=None):
"""Upload a pack to a remote repository.
:param path: Repository path
:param generate_pack_contents: Function that can return a sequence of the
shas of the objects to upload.
:param progress: Optional callback called with progress updates
:raises SendPackError: if server rejects the pack data
:raises UpdateRefsError: if the server supports report-status
and rejects ref updates
"""
proto, unused_can_read = self._connect('receive-pack', path)
old_refs, server_capabilities = self._read_refs(proto)
negotiated_capabilities = self._send_capabilities & server_capabilities
try:
new_refs = determine_wants(dict(old_refs))
except:
proto.write_pkt_line(None)
raise
if new_refs is None:
proto.write_pkt_line(None)
return old_refs
(have, want) = self._handle_receive_pack_head(proto,
negotiated_capabilities, old_refs, new_refs)
if not want and old_refs == new_refs:
return new_refs
objects = generate_pack_contents(have, want)
if len(objects) > 0:
entries, sha = write_pack_objects(proto.write_file(), objects)
self._handle_receive_pack_tail(proto, negotiated_capabilities,
progress)
return new_refs
def fetch_pack(self, path, determine_wants, graph_walker, pack_data,
progress=None):
"""Retrieve a pack from a git smart server.
:param determine_wants: Callback that returns list of commits to fetch
:param graph_walker: Object with next() and ack().
:param pack_data: Callback called for each bit of data in the pack
:param progress: Callback for progress reports (strings)
"""
proto, can_read = self._connect('upload-pack', path)
refs, server_capabilities = self._read_refs(proto)
negotiated_capabilities = self._fetch_capabilities & server_capabilities
try:
wants = determine_wants(refs)
except:
proto.write_pkt_line(None)
raise
if wants is not None:
wants = [cid for cid in wants if cid != ZERO_SHA]
if not wants:
proto.write_pkt_line(None)
return refs
self._handle_upload_pack_head(proto, negotiated_capabilities,
graph_walker, wants, can_read)
self._handle_upload_pack_tail(proto, negotiated_capabilities,
graph_walker, pack_data, progress)
return refs
def archive(self, path, committish, write_data, progress=None):
proto, can_read = self._connect('upload-archive', path)
proto.write_pkt_line("argument %s" % committish)
proto.write_pkt_line(None)
pkt = proto.read_pkt_line()
if pkt == "NACK\n":
return
elif pkt == "ACK\n":
pass
elif pkt.startswith("ERR "):
raise GitProtocolError(pkt[4:].rstrip("\n"))
else:
raise AssertionError("invalid response %r" % pkt)
ret = proto.read_pkt_line()
if ret is not None:
raise AssertionError("expected pkt tail")
self._read_side_band64k_data(proto, {1: write_data, 2: progress})
class TCPGitClient(TraditionalGitClient):
"""A Git Client that works over TCP directly (i.e. git://)."""
def __init__(self, host, port=None, *args, **kwargs):
if port is None:
port = TCP_GIT_PORT
self._host = host
self._port = port
TraditionalGitClient.__init__(self, *args, **kwargs)
def _connect(self, cmd, path):
sockaddrs = socket.getaddrinfo(self._host, self._port,
socket.AF_UNSPEC, socket.SOCK_STREAM)
s = None
err = socket.error("no address found for %s" % self._host)
for (family, socktype, proto, canonname, sockaddr) in sockaddrs:
s = socket.socket(family, socktype, proto)
s.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
try:
s.connect(sockaddr)
break
except socket.error, err:
if s is not None:
s.close()
s = None
if s is None:
raise err
# -1 means system default buffering
rfile = s.makefile('rb', -1)
# 0 means unbuffered
wfile = s.makefile('wb', 0)
proto = Protocol(rfile.read, wfile.write,
report_activity=self._report_activity)
if path.startswith("/~"):
path = path[1:]
proto.send_cmd('git-%s' % cmd, path, 'host=%s' % self._host)
return proto, lambda: _fileno_can_read(s)
class SubprocessWrapper(object):
"""A socket-like object that talks to a subprocess via pipes."""
def __init__(self, proc):
self.proc = proc
self.read = proc.stdout.read
self.write = proc.stdin.write
def can_read(self):
if subprocess.mswindows:
from msvcrt import get_osfhandle
from win32pipe import PeekNamedPipe
handle = get_osfhandle(self.proc.stdout.fileno())
return PeekNamedPipe(handle, 0)[2] != 0
else:
return _fileno_can_read(self.proc.stdout.fileno())
def close(self):
self.proc.stdin.close()
self.proc.stdout.close()
self.proc.wait()
class SubprocessGitClient(TraditionalGitClient):
"""Git client that talks to a server using a subprocess."""
def __init__(self, *args, **kwargs):
self._connection = None
self._stderr = None
self._stderr = kwargs.get('stderr')
if 'stderr' in kwargs:
del kwargs['stderr']
TraditionalGitClient.__init__(self, *args, **kwargs)
def _connect(self, service, path):
import subprocess
argv = ['git', service, path]
p = SubprocessWrapper(
subprocess.Popen(argv, bufsize=0, stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=self._stderr))
return Protocol(p.read, p.write,
report_activity=self._report_activity), p.can_read
class SSHVendor(object):
def connect_ssh(self, host, command, username=None, port=None):
import subprocess
#FIXME: This has no way to deal with passwords..
args = ['ssh', '-x']
if port is not None:
args.extend(['-p', str(port)])
if username is not None:
host = '%s@%s' % (username, host)
args.append(host)
proc = subprocess.Popen(args + command,
stdin=subprocess.PIPE,
stdout=subprocess.PIPE)
return SubprocessWrapper(proc)
# Can be overridden by users
get_ssh_vendor = SSHVendor
class SSHGitClient(TraditionalGitClient):
def __init__(self, host, port=None, username=None, *args, **kwargs):
self.host = host
self.port = port
self.username = username
TraditionalGitClient.__init__(self, *args, **kwargs)
self.alternative_paths = {}
def _get_cmd_path(self, cmd):
return self.alternative_paths.get(cmd, 'git-%s' % cmd)
def _connect(self, cmd, path):
con = get_ssh_vendor().connect_ssh(
self.host, ["%s '%s'" % (self._get_cmd_path(cmd), path)],
port=self.port, username=self.username)
return (Protocol(con.read, con.write, report_activity=self._report_activity),
con.can_read)
class HttpGitClient(GitClient):
def __init__(self, base_url, dumb=None, *args, **kwargs):
self.base_url = base_url.rstrip("/") + "/"
self.dumb = dumb
GitClient.__init__(self, *args, **kwargs)
def _get_url(self, path):
return urlparse.urljoin(self.base_url, path).rstrip("/") + "/"
def _perform(self, req):
"""Perform a HTTP request.
This is provided so subclasses can provide their own version.
:param req: urllib2.Request instance
:return: matching response
"""
return urllib2.urlopen(req)
def _discover_references(self, service, url):
assert url[-1] == "/"
url = urlparse.urljoin(url, "info/refs")
headers = {}
if self.dumb != False:
url += "?service=%s" % service
headers["Content-Type"] = "application/x-%s-request" % service
req = urllib2.Request(url, headers=headers)
resp = self._perform(req)
if resp.getcode() == 404:
raise NotGitRepository()
if resp.getcode() != 200:
raise GitProtocolError("unexpected http response %d" %
resp.getcode())
self.dumb = (not resp.info().gettype().startswith("application/x-git-"))
proto = Protocol(resp.read, None)
if not self.dumb:
# The first line should mention the service
pkts = list(proto.read_pkt_seq())
if pkts != [('# service=%s\n' % service)]:
raise GitProtocolError(
"unexpected first line %r from smart server" % pkts)
return self._read_refs(proto)
def _smart_request(self, service, url, data):
assert url[-1] == "/"
url = urlparse.urljoin(url, service)
req = urllib2.Request(url,
headers={"Content-Type": "application/x-%s-request" % service},
data=data)
resp = self._perform(req)
if resp.getcode() == 404:
raise NotGitRepository()
if resp.getcode() != 200:
raise GitProtocolError("Invalid HTTP response from server: %d"
% resp.getcode())
if resp.info().gettype() != ("application/x-%s-result" % service):
raise GitProtocolError("Invalid content-type from server: %s"
% resp.info().gettype())
return resp
def send_pack(self, path, determine_wants, generate_pack_contents,
progress=None):
"""Upload a pack to a remote repository.
:param path: Repository path
:param generate_pack_contents: Function that can return a sequence of the
shas of the objects to upload.
:param progress: Optional progress function
:raises SendPackError: if server rejects the pack data
:raises UpdateRefsError: if the server supports report-status
and rejects ref updates
"""
url = self._get_url(path)
old_refs, server_capabilities = self._discover_references(
"git-receive-pack", url)
negotiated_capabilities = self._send_capabilities & server_capabilities
new_refs = determine_wants(dict(old_refs))
if new_refs is None:
return old_refs
if self.dumb:
raise NotImplementedError(self.fetch_pack)
req_data = StringIO()
req_proto = Protocol(None, req_data.write)
(have, want) = self._handle_receive_pack_head(
req_proto, negotiated_capabilities, old_refs, new_refs)
if not want and old_refs == new_refs:
return new_refs
objects = generate_pack_contents(have, want)
if len(objects) > 0:
entries, sha = write_pack_objects(req_proto.write_file(), objects)
resp = self._smart_request("git-receive-pack", url,
data=req_data.getvalue())
resp_proto = Protocol(resp.read, None)
self._handle_receive_pack_tail(resp_proto, negotiated_capabilities,
progress)
return new_refs
def fetch_pack(self, path, determine_wants, graph_walker, pack_data,
progress=None):
"""Retrieve a pack from a git smart server.
:param determine_wants: Callback that returns list of commits to fetch
:param graph_walker: Object with next() and ack().
:param pack_data: Callback called for each bit of data in the pack
:param progress: Callback for progress reports (strings)
:return: Dictionary with the refs of the remote repository
"""
url = self._get_url(path)
refs, server_capabilities = self._discover_references(
"git-upload-pack", url)
negotiated_capabilities = server_capabilities
wants = determine_wants(refs)
if wants is not None:
wants = [cid for cid in wants if cid != ZERO_SHA]
if not wants:
return refs
if self.dumb:
raise NotImplementedError(self.send_pack)
req_data = StringIO()
req_proto = Protocol(None, req_data.write)
self._handle_upload_pack_head(req_proto,
negotiated_capabilities, graph_walker, wants,
lambda: False)
resp = self._smart_request("git-upload-pack", url,
data=req_data.getvalue())
resp_proto = Protocol(resp.read, None)
self._handle_upload_pack_tail(resp_proto, negotiated_capabilities,
graph_walker, pack_data, progress)
return refs
def get_transport_and_path(uri, **kwargs):
"""Obtain a git client from a URI or path.
:param uri: URI or path
:param thin_packs: Whether or not thin packs should be retrieved
:param report_activity: Optional callback for reporting transport
activity.
:return: Tuple with client instance and relative path.
"""
parsed = urlparse.urlparse(uri)
if parsed.scheme == 'git':
return (TCPGitClient(parsed.hostname, port=parsed.port, **kwargs),
parsed.path)
elif parsed.scheme == 'git+ssh':
return SSHGitClient(parsed.hostname, port=parsed.port,
username=parsed.username, **kwargs), parsed.path
elif parsed.scheme in ('http', 'https'):
return HttpGitClient(urlparse.urlunparse(parsed)), parsed.path
if parsed.scheme and not parsed.netloc:
# SSH with no user@, zero or one leading slash.
return SSHGitClient(parsed.scheme, **kwargs), parsed.path
elif parsed.scheme:
raise ValueError('Unknown git protocol scheme: %s' % parsed.scheme)
elif '@' in parsed.path and ':' in parsed.path:
# SSH with user@host:foo.
user_host, path = parsed.path.split(':')
user, host = user_host.rsplit('@')
return SSHGitClient(host, username=user, **kwargs), path
# Otherwise, assume it's a local path.
return SubprocessGitClient(**kwargs), uri
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