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# Copyright (C) 2006-2011 Canonical Ltd
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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"""The 'medium' layer for the smart servers and clients.
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"Medium" here is the noun meaning "a means of transmission", not the adjective
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for "the quality between big and small."
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Media carry the bytes of the requests somehow (e.g. via TCP, wrapped in HTTP, or
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over SSH), and pass them to and from the protocol logic. See the overview in
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breezy/transport/smart/__init__.py.
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from __future__ import absolute_import
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import thread as _thread
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from ...lazy_import import lazy_import
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lazy_import(globals(), """
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from breezy.i18n import gettext
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from breezy.bzr.smart import client, protocol, request, signals, vfs
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from breezy.transport import ssh
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# Throughout this module buffer size parameters are either limited to be at
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# most _MAX_READ_SIZE, or are ignored and _MAX_READ_SIZE is used instead.
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# For this module's purposes, MAX_SOCKET_CHUNK is a reasonable size for reads
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# from non-sockets as well.
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_MAX_READ_SIZE = osutils.MAX_SOCKET_CHUNK
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class HpssVfsRequestNotAllowed(errors.BzrError):
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_fmt = ("VFS requests over the smart server are not allowed. Encountered: "
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"%(method)s, %(arguments)s.")
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def __init__(self, method, arguments):
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self.arguments = arguments
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def _get_protocol_factory_for_bytes(bytes):
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"""Determine the right protocol factory for 'bytes'.
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This will return an appropriate protocol factory depending on the version
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of the protocol being used, as determined by inspecting the given bytes.
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The bytes should have at least one newline byte (i.e. be a whole line),
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otherwise it's possible that a request will be incorrectly identified as
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Typical use would be::
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factory, unused_bytes = _get_protocol_factory_for_bytes(bytes)
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server_protocol = factory(transport, write_func, root_client_path)
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server_protocol.accept_bytes(unused_bytes)
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:param bytes: a str of bytes of the start of the request.
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:returns: 2-tuple of (protocol_factory, unused_bytes). protocol_factory is
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a callable that takes three args: transport, write_func,
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root_client_path. unused_bytes are any bytes that were not part of a
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protocol version marker.
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if bytes.startswith(protocol.MESSAGE_VERSION_THREE):
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protocol_factory = protocol.build_server_protocol_three
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bytes = bytes[len(protocol.MESSAGE_VERSION_THREE):]
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elif bytes.startswith(protocol.REQUEST_VERSION_TWO):
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protocol_factory = protocol.SmartServerRequestProtocolTwo
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bytes = bytes[len(protocol.REQUEST_VERSION_TWO):]
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protocol_factory = protocol.SmartServerRequestProtocolOne
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return protocol_factory, bytes
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def _get_line(read_bytes_func):
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"""Read bytes using read_bytes_func until a newline byte.
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This isn't particularly efficient, so should only be used when the
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expected size of the line is quite short.
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:returns: a tuple of two strs: (line, excess)
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while newline_pos == -1:
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new_bytes = read_bytes_func(1)
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# Ran out of bytes before receiving a complete line.
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newline_pos = bytes.find(b'\n')
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line = bytes[:newline_pos + 1]
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excess = bytes[newline_pos + 1:]
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class SmartMedium(object):
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"""Base class for smart protocol media, both client- and server-side."""
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self._push_back_buffer = None
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def _push_back(self, data):
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"""Return unused bytes to the medium, because they belong to the next
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This sets the _push_back_buffer to the given bytes.
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if not isinstance(data, bytes):
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raise TypeError(data)
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if self._push_back_buffer is not None:
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raise AssertionError(
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"_push_back called when self._push_back_buffer is %r"
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% (self._push_back_buffer,))
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self._push_back_buffer = data
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def _get_push_back_buffer(self):
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if self._push_back_buffer == b'':
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raise AssertionError(
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'%s._push_back_buffer should never be the empty string, '
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'which can be confused with EOF' % (self,))
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bytes = self._push_back_buffer
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self._push_back_buffer = None
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def read_bytes(self, desired_count):
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"""Read some bytes from this medium.
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:returns: some bytes, possibly more or less than the number requested
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in 'desired_count' depending on the medium.
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if self._push_back_buffer is not None:
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return self._get_push_back_buffer()
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bytes_to_read = min(desired_count, _MAX_READ_SIZE)
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return self._read_bytes(bytes_to_read)
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def _read_bytes(self, count):
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raise NotImplementedError(self._read_bytes)
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"""Read bytes from this request's response until a newline byte.
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This isn't particularly efficient, so should only be used when the
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expected size of the line is quite short.
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:returns: a string of bytes ending in a newline (byte 0x0A).
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line, excess = _get_line(self.read_bytes)
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self._push_back(excess)
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def _report_activity(self, bytes, direction):
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"""Notify that this medium has activity.
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Implementations should call this from all methods that actually do IO.
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Be careful that it's not called twice, if one method is implemented on
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:param bytes: Number of bytes read or written.
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:param direction: 'read' or 'write' or None.
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ui.ui_factory.report_transport_activity(self, bytes, direction)
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_bad_file_descriptor = (errno.EBADF,)
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if sys.platform == 'win32':
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# Given on Windows if you pass a closed socket to select.select. Probably
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# also given if you pass a file handle to select.
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_bad_file_descriptor += (WSAENOTSOCK,)
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class SmartServerStreamMedium(SmartMedium):
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"""Handles smart commands coming over a stream.
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The stream may be a pipe connected to sshd, or a tcp socket, or an
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in-process fifo for testing.
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One instance is created for each connected client; it can serve multiple
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requests in the lifetime of the connection.
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The server passes requests through to an underlying backing transport,
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which will typically be a LocalTransport looking at the server's filesystem.
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:ivar _push_back_buffer: a str of bytes that have been read from the stream
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but not used yet, or None if there are no buffered bytes. Subclasses
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should make sure to exhaust this buffer before reading more bytes from
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the stream. See also the _push_back method.
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def __init__(self, backing_transport, root_client_path='/', timeout=None):
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"""Construct new server.
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:param backing_transport: Transport for the directory served.
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# backing_transport could be passed to serve instead of __init__
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self.backing_transport = backing_transport
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self.root_client_path = root_client_path
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self.finished = False
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raise AssertionError('You must supply a timeout.')
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self._client_timeout = timeout
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self._client_poll_timeout = min(timeout / 10.0, 1.0)
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SmartMedium.__init__(self)
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"""Serve requests until the client disconnects."""
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# Keep a reference to stderr because the sys module's globals get set to
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# None during interpreter shutdown.
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from sys import stderr
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while not self.finished:
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server_protocol = self._build_protocol()
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self._serve_one_request(server_protocol)
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except errors.ConnectionTimeout as e:
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trace.note('%s' % (e,))
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trace.log_exception_quietly()
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self._disconnect_client()
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# We reported it, no reason to make a big fuss.
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except Exception as e:
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stderr.write("%s terminating on exception %s\n" % (self, e))
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self._disconnect_client()
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def _stop_gracefully(self):
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"""When we finish this message, stop looking for more."""
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trace.mutter('Stopping %s' % (self,))
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def _disconnect_client(self):
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"""Close the current connection. We stopped due to a timeout/etc."""
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# The default implementation is a no-op, because that is all we used to
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# do when disconnecting from a client. I suppose we never had the
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# *server* initiate a disconnect, before
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def _wait_for_bytes_with_timeout(self, timeout_seconds):
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"""Wait for more bytes to be read, but timeout if none available.
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This allows us to detect idle connections, and stop trying to read from
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them, without setting the socket itself to non-blocking. This also
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allows us to specify when we watch for idle timeouts.
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:return: Did we timeout? (True if we timed out, False if there is data
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raise NotImplementedError(self._wait_for_bytes_with_timeout)
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def _build_protocol(self):
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"""Identifies the version of the incoming request, and returns an
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a protocol object that can interpret it.
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If more bytes than the version prefix of the request are read, they will
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be fed into the protocol before it is returned.
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:returns: a SmartServerRequestProtocol.
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self._wait_for_bytes_with_timeout(self._client_timeout)
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# We're stopping, so don't try to do any more work
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bytes = self._get_line()
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protocol_factory, unused_bytes = _get_protocol_factory_for_bytes(bytes)
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protocol = protocol_factory(
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self.backing_transport, self._write_out, self.root_client_path)
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protocol.accept_bytes(unused_bytes)
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def _wait_on_descriptor(self, fd, timeout_seconds):
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"""select() on a file descriptor, waiting for nonblocking read()
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This will raise a ConnectionTimeout exception if we do not get a
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readable handle before timeout_seconds.
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t_end = self._timer() + timeout_seconds
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poll_timeout = min(timeout_seconds, self._client_poll_timeout)
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while not rs and not xs and self._timer() < t_end:
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rs, _, xs = select.select([fd], [], [fd], poll_timeout)
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except (select.error, socket.error) as e:
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err = getattr(e, 'errno', None)
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if err is None and getattr(e, 'args', None) is not None:
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# select.error doesn't have 'errno', it just has args[0]
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if err in _bad_file_descriptor:
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return # Not a socket indicates read() will fail
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elif err == errno.EINTR:
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# Interrupted, keep looping.
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return # Socket may already be closed
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raise errors.ConnectionTimeout('disconnecting client after %.1f seconds'
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% (timeout_seconds,))
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def _serve_one_request(self, protocol):
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"""Read one request from input, process, send back a response.
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:param protocol: a SmartServerRequestProtocol.
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self._serve_one_request_unguarded(protocol)
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except KeyboardInterrupt:
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except Exception as e:
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self.terminate_due_to_error()
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def terminate_due_to_error(self):
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"""Called when an unhandled exception from the protocol occurs."""
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raise NotImplementedError(self.terminate_due_to_error)
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def _read_bytes(self, desired_count):
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"""Get some bytes from the medium.
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:param desired_count: number of bytes we want to read.
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raise NotImplementedError(self._read_bytes)
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class SmartServerSocketStreamMedium(SmartServerStreamMedium):
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def __init__(self, sock, backing_transport, root_client_path='/',
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:param sock: the socket the server will read from. It will be put
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SmartServerStreamMedium.__init__(
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self, backing_transport, root_client_path=root_client_path,
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sock.setblocking(True)
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# Get the getpeername now, as we might be closed later when we care.
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self._client_info = sock.getpeername()
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self._client_info = '<unknown>'
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return '%s(client=%s)' % (self.__class__.__name__, self._client_info)
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return '%s.%s(client=%s)' % (self.__module__, self.__class__.__name__,
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def _serve_one_request_unguarded(self, protocol):
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while protocol.next_read_size():
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# We can safely try to read large chunks. If there is less data
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# than MAX_SOCKET_CHUNK ready, the socket will just return a
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# short read immediately rather than block.
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bytes = self.read_bytes(osutils.MAX_SOCKET_CHUNK)
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protocol.accept_bytes(bytes)
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self._push_back(protocol.unused_data)
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def _disconnect_client(self):
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"""Close the current connection. We stopped due to a timeout/etc."""
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def _wait_for_bytes_with_timeout(self, timeout_seconds):
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"""Wait for more bytes to be read, but timeout if none available.
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This allows us to detect idle connections, and stop trying to read from
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them, without setting the socket itself to non-blocking. This also
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allows us to specify when we watch for idle timeouts.
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:return: None, this will raise ConnectionTimeout if we time out before
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return self._wait_on_descriptor(self.socket, timeout_seconds)
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def _read_bytes(self, desired_count):
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return osutils.read_bytes_from_socket(
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self.socket, self._report_activity)
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def terminate_due_to_error(self):
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# TODO: This should log to a server log file, but no such thing
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# exists yet. Andrew Bennetts 2006-09-29.
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def _write_out(self, bytes):
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tstart = osutils.timer_func()
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osutils.send_all(self.socket, bytes, self._report_activity)
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if 'hpss' in debug.debug_flags:
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thread_id = _thread.get_ident()
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trace.mutter('%12s: [%s] %d bytes to the socket in %.3fs'
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% ('wrote', thread_id, len(bytes),
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osutils.timer_func() - tstart))
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class SmartServerPipeStreamMedium(SmartServerStreamMedium):
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def __init__(self, in_file, out_file, backing_transport, timeout=None):
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"""Construct new server.
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:param in_file: Python file from which requests can be read.
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:param out_file: Python file to write responses.
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:param backing_transport: Transport for the directory served.
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SmartServerStreamMedium.__init__(self, backing_transport,
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if sys.platform == 'win32':
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# force binary mode for files
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for f in (in_file, out_file):
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fileno = getattr(f, 'fileno', None)
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msvcrt.setmode(fileno(), os.O_BINARY)
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"""See SmartServerStreamMedium.serve"""
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# This is the regular serve, except it adds signal trapping for soft
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stop_gracefully = self._stop_gracefully
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signals.register_on_hangup(id(self), stop_gracefully)
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return super(SmartServerPipeStreamMedium, self).serve()
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signals.unregister_on_hangup(id(self))
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def _serve_one_request_unguarded(self, protocol):
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# We need to be careful not to read past the end of the current
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# request, or else the read from the pipe will block, so we use
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# protocol.next_read_size().
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bytes_to_read = protocol.next_read_size()
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if bytes_to_read == 0:
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# Finished serving this request.
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bytes = self.read_bytes(bytes_to_read)
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# Connection has been closed.
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protocol.accept_bytes(bytes)
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def _disconnect_client(self):
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def _wait_for_bytes_with_timeout(self, timeout_seconds):
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"""Wait for more bytes to be read, but timeout if none available.
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This allows us to detect idle connections, and stop trying to read from
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them, without setting the socket itself to non-blocking. This also
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allows us to specify when we watch for idle timeouts.
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:return: None, this will raise ConnectionTimeout if we time out before
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if (getattr(self._in, 'fileno', None) is None
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or sys.platform == 'win32'):
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# You can't select() file descriptors on Windows.
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return self._wait_on_descriptor(self._in, timeout_seconds)
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except io.UnsupportedOperation:
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def _read_bytes(self, desired_count):
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return self._in.read(desired_count)
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def terminate_due_to_error(self):
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# TODO: This should log to a server log file, but no such thing
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# exists yet. Andrew Bennetts 2006-09-29.
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def _write_out(self, bytes):
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self._out.write(bytes)
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class SmartClientMediumRequest(object):
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"""A request on a SmartClientMedium.
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Each request allows bytes to be provided to it via accept_bytes, and then
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the response bytes to be read via read_bytes.
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request.accept_bytes('123')
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request.finished_writing()
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result = request.read_bytes(3)
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request.finished_reading()
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It is up to the individual SmartClientMedium whether multiple concurrent
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requests can exist. See SmartClientMedium.get_request to obtain instances
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of SmartClientMediumRequest, and the concrete Medium you are using for
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details on concurrency and pipelining.
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def __init__(self, medium):
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"""Construct a SmartClientMediumRequest for the medium medium."""
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self._medium = medium
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# we track state by constants - we may want to use the same
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# pattern as BodyReader if it gets more complex.
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# valid states are: "writing", "reading", "done"
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self._state = "writing"
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def accept_bytes(self, bytes):
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"""Accept bytes for inclusion in this request.
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This method may not be called after finished_writing() has been
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called. It depends upon the Medium whether or not the bytes will be
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immediately transmitted. Message based Mediums will tend to buffer the
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bytes until finished_writing() is called.
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:param bytes: A bytestring.
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if self._state != "writing":
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raise errors.WritingCompleted(self)
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self._accept_bytes(bytes)
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def _accept_bytes(self, bytes):
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"""Helper for accept_bytes.
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Accept_bytes checks the state of the request to determing if bytes
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should be accepted. After that it hands off to _accept_bytes to do the
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raise NotImplementedError(self._accept_bytes)
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def finished_reading(self):
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"""Inform the request that all desired data has been read.
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This will remove the request from the pipeline for its medium (if the
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medium supports pipelining) and any further calls to methods on the
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request will raise ReadingCompleted.
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if self._state == "writing":
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raise errors.WritingNotComplete(self)
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if self._state != "reading":
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raise errors.ReadingCompleted(self)
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self._finished_reading()
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def _finished_reading(self):
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"""Helper for finished_reading.
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finished_reading checks the state of the request to determine if
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finished_reading is allowed, and if it is hands off to _finished_reading
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to perform the action.
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raise NotImplementedError(self._finished_reading)
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def finished_writing(self):
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"""Finish the writing phase of this request.
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This will flush all pending data for this request along the medium.
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After calling finished_writing, you may not call accept_bytes anymore.
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if self._state != "writing":
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raise errors.WritingCompleted(self)
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self._state = "reading"
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self._finished_writing()
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def _finished_writing(self):
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"""Helper for finished_writing.
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finished_writing checks the state of the request to determine if
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finished_writing is allowed, and if it is hands off to _finished_writing
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to perform the action.
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raise NotImplementedError(self._finished_writing)
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def read_bytes(self, count):
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"""Read bytes from this requests response.
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This method will block and wait for count bytes to be read. It may not
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be invoked until finished_writing() has been called - this is to ensure
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a message-based approach to requests, for compatibility with message
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based mediums like HTTP.
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if self._state == "writing":
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raise errors.WritingNotComplete(self)
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if self._state != "reading":
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raise errors.ReadingCompleted(self)
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return self._read_bytes(count)
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def _read_bytes(self, count):
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"""Helper for SmartClientMediumRequest.read_bytes.
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read_bytes checks the state of the request to determing if bytes
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should be read. After that it hands off to _read_bytes to do the
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By default this forwards to self._medium.read_bytes because we are
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operating on the medium's stream.
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return self._medium.read_bytes(count)
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line = self._read_line()
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if not line.endswith(b'\n'):
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# end of file encountered reading from server
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raise errors.ConnectionReset(
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"Unexpected end of message. Please check connectivity "
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"and permissions, and report a bug if problems persist.")
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def _read_line(self):
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"""Helper for SmartClientMediumRequest.read_line.
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By default this forwards to self._medium._get_line because we are
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operating on the medium's stream.
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return self._medium._get_line()
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class _VfsRefuser(object):
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"""An object that refuses all VFS requests.
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client._SmartClient.hooks.install_named_hook(
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'call', self.check_vfs, 'vfs refuser')
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def check_vfs(self, params):
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request_method = request.request_handlers.get(params.method)
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# A method we don't know about doesn't count as a VFS method.
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if issubclass(request_method, vfs.VfsRequest):
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raise HpssVfsRequestNotAllowed(params.method, params.args)
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class _DebugCounter(object):
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"""An object that counts the HPSS calls made to each client medium.
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When a medium is garbage-collected, or failing that when
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breezy.global_state exits, the total number of calls made on that medium
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are reported via trace.note.
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self.counts = weakref.WeakKeyDictionary()
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client._SmartClient.hooks.install_named_hook(
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'call', self.increment_call_count, 'hpss call counter')
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breezy.get_global_state().cleanups.add_cleanup(self.flush_all)
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def track(self, medium):
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"""Start tracking calls made to a medium.
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This only keeps a weakref to the medium, so shouldn't affect the
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medium_repr = repr(medium)
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# Add this medium to the WeakKeyDictionary
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self.counts[medium] = dict(count=0, vfs_count=0,
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medium_repr=medium_repr)
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# Weakref callbacks are fired in reverse order of their association
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# with the referenced object. So we add a weakref *after* adding to
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# the WeakKeyDict so that we can report the value from it before the
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# entry is removed by the WeakKeyDict's own callback.
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ref = weakref.ref(medium, self.done)
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def increment_call_count(self, params):
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# Increment the count in the WeakKeyDictionary
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value = self.counts[params.medium]
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request_method = request.request_handlers.get(params.method)
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# A method we don't know about doesn't count as a VFS method.
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if issubclass(request_method, vfs.VfsRequest):
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value['vfs_count'] += 1
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value = self.counts[ref]
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count, vfs_count, medium_repr = (
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value['count'], value['vfs_count'], value['medium_repr'])
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# In case this callback is invoked for the same ref twice (by the
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# weakref callback and by the atexit function), set the call count back
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# to 0 so this item won't be reported twice.
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value['vfs_count'] = 0
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trace.note(gettext('HPSS calls: {0} ({1} vfs) {2}').format(
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count, vfs_count, medium_repr))
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for ref in list(self.counts.keys()):
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_debug_counter = None
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class SmartClientMedium(SmartMedium):
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"""Smart client is a medium for sending smart protocol requests over."""
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def __init__(self, base):
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super(SmartClientMedium, self).__init__()
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self._protocol_version_error = None
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self._protocol_version = None
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self._done_hello = False
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# Be optimistic: we assume the remote end can accept new remote
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# requests until we get an error saying otherwise.
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# _remote_version_is_before tracks the bzr version the remote side
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# can be based on what we've seen so far.
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self._remote_version_is_before = None
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# Install debug hook function if debug flag is set.
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if 'hpss' in debug.debug_flags:
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global _debug_counter
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if _debug_counter is None:
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_debug_counter = _DebugCounter()
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_debug_counter.track(self)
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if 'hpss_client_no_vfs' in debug.debug_flags:
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if _vfs_refuser is None:
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_vfs_refuser = _VfsRefuser()
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def _is_remote_before(self, version_tuple):
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"""Is it possible the remote side supports RPCs for a given version?
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needed_version = (1, 2)
782
if medium._is_remote_before(needed_version):
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fallback_to_pre_1_2_rpc()
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except UnknownSmartMethod:
788
medium._remember_remote_is_before(needed_version)
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fallback_to_pre_1_2_rpc()
791
:seealso: _remember_remote_is_before
793
if self._remote_version_is_before is None:
794
# So far, the remote side seems to support everything
796
return version_tuple >= self._remote_version_is_before
798
def _remember_remote_is_before(self, version_tuple):
799
"""Tell this medium that the remote side is older the given version.
801
:seealso: _is_remote_before
803
if (self._remote_version_is_before is not None and
804
version_tuple > self._remote_version_is_before):
805
# We have been told that the remote side is older than some version
806
# which is newer than a previously supplied older-than version.
807
# This indicates that some smart verb call is not guarded
808
# appropriately (it should simply not have been tried).
810
"_remember_remote_is_before(%r) called, but "
811
"_remember_remote_is_before(%r) was called previously.", version_tuple, self._remote_version_is_before)
812
if 'hpss' in debug.debug_flags:
813
ui.ui_factory.show_warning(
814
"_remember_remote_is_before(%r) called, but "
815
"_remember_remote_is_before(%r) was called previously."
816
% (version_tuple, self._remote_version_is_before))
818
self._remote_version_is_before = version_tuple
820
def protocol_version(self):
821
"""Find out if 'hello' smart request works."""
822
if self._protocol_version_error is not None:
823
raise self._protocol_version_error
824
if not self._done_hello:
826
medium_request = self.get_request()
827
# Send a 'hello' request in protocol version one, for maximum
828
# backwards compatibility.
829
client_protocol = protocol.SmartClientRequestProtocolOne(
831
client_protocol.query_version()
832
self._done_hello = True
833
except errors.SmartProtocolError as e:
834
# Cache the error, just like we would cache a successful
836
self._protocol_version_error = e
840
def should_probe(self):
841
"""Should RemoteBzrDirFormat.probe_transport send a smart request on
844
Some transports are unambiguously smart-only; there's no need to check
845
if the transport is able to carry smart requests, because that's all
846
it is for. In those cases, this method should return False.
848
But some HTTP transports can sometimes fail to carry smart requests,
849
but still be usuable for accessing remote bzrdirs via plain file
850
accesses. So for those transports, their media should return True here
851
so that RemoteBzrDirFormat can determine if it is appropriate for that
856
def disconnect(self):
857
"""If this medium maintains a persistent connection, close it.
859
The default implementation does nothing.
862
def remote_path_from_transport(self, transport):
863
"""Convert transport into a path suitable for using in a request.
865
Note that the resulting remote path doesn't encode the host name or
866
anything but path, so it is only safe to use it in requests sent over
867
the medium from the matching transport.
869
medium_base = urlutils.join(self.base, '/')
870
rel_url = urlutils.relative_url(medium_base, transport.base)
871
return urlutils.unquote(rel_url)
874
class SmartClientStreamMedium(SmartClientMedium):
875
"""Stream based medium common class.
877
SmartClientStreamMediums operate on a stream. All subclasses use a common
878
SmartClientStreamMediumRequest for their requests, and should implement
879
_accept_bytes and _read_bytes to allow the request objects to send and
883
def __init__(self, base):
884
SmartClientMedium.__init__(self, base)
885
self._current_request = None
887
def accept_bytes(self, bytes):
888
self._accept_bytes(bytes)
891
"""The SmartClientStreamMedium knows how to close the stream when it is
897
"""Flush the output stream.
899
This method is used by the SmartClientStreamMediumRequest to ensure that
900
all data for a request is sent, to avoid long timeouts or deadlocks.
902
raise NotImplementedError(self._flush)
904
def get_request(self):
905
"""See SmartClientMedium.get_request().
907
SmartClientStreamMedium always returns a SmartClientStreamMediumRequest
910
return SmartClientStreamMediumRequest(self)
913
"""We have been disconnected, reset current state.
915
This resets things like _current_request and connected state.
918
self._current_request = None
921
class SmartSimplePipesClientMedium(SmartClientStreamMedium):
922
"""A client medium using simple pipes.
924
This client does not manage the pipes: it assumes they will always be open.
927
def __init__(self, readable_pipe, writeable_pipe, base):
928
SmartClientStreamMedium.__init__(self, base)
929
self._readable_pipe = readable_pipe
930
self._writeable_pipe = writeable_pipe
932
def _accept_bytes(self, data):
933
"""See SmartClientStreamMedium.accept_bytes."""
935
self._writeable_pipe.write(data)
937
if e.errno in (errno.EINVAL, errno.EPIPE):
938
raise errors.ConnectionReset(
939
"Error trying to write to subprocess", e)
941
self._report_activity(len(data), 'write')
944
"""See SmartClientStreamMedium._flush()."""
945
# Note: If flush were to fail, we'd like to raise ConnectionReset, etc.
946
# However, testing shows that even when the child process is
947
# gone, this doesn't error.
948
self._writeable_pipe.flush()
950
def _read_bytes(self, count):
951
"""See SmartClientStreamMedium._read_bytes."""
952
bytes_to_read = min(count, _MAX_READ_SIZE)
953
data = self._readable_pipe.read(bytes_to_read)
954
self._report_activity(len(data), 'read')
958
class SSHParams(object):
959
"""A set of parameters for starting a remote bzr via SSH."""
961
def __init__(self, host, port=None, username=None, password=None,
962
bzr_remote_path='bzr'):
965
self.username = username
966
self.password = password
967
self.bzr_remote_path = bzr_remote_path
970
class SmartSSHClientMedium(SmartClientStreamMedium):
971
"""A client medium using SSH.
973
It delegates IO to a SmartSimplePipesClientMedium or
974
SmartClientAlreadyConnectedSocketMedium (depending on platform).
977
def __init__(self, base, ssh_params, vendor=None):
978
"""Creates a client that will connect on the first use.
980
:param ssh_params: A SSHParams instance.
981
:param vendor: An optional override for the ssh vendor to use. See
982
breezy.transport.ssh for details on ssh vendors.
984
self._real_medium = None
985
self._ssh_params = ssh_params
986
# for the benefit of progress making a short description of this
988
self._scheme = 'bzr+ssh'
989
# SmartClientStreamMedium stores the repr of this object in its
990
# _DebugCounter so we have to store all the values used in our repr
991
# method before calling the super init.
992
SmartClientStreamMedium.__init__(self, base)
993
self._vendor = vendor
994
self._ssh_connection = None
997
if self._ssh_params.port is None:
1000
maybe_port = ':%s' % self._ssh_params.port
1001
if self._ssh_params.username is None:
1004
maybe_user = '%s@' % self._ssh_params.username
1005
return "%s(%s://%s%s%s/)" % (
1006
self.__class__.__name__,
1009
self._ssh_params.host,
1012
def _accept_bytes(self, bytes):
1013
"""See SmartClientStreamMedium.accept_bytes."""
1014
self._ensure_connection()
1015
self._real_medium.accept_bytes(bytes)
1017
def disconnect(self):
1018
"""See SmartClientMedium.disconnect()."""
1019
if self._real_medium is not None:
1020
self._real_medium.disconnect()
1021
self._real_medium = None
1022
if self._ssh_connection is not None:
1023
self._ssh_connection.close()
1024
self._ssh_connection = None
1026
def _ensure_connection(self):
1027
"""Connect this medium if not already connected."""
1028
if self._real_medium is not None:
1030
if self._vendor is None:
1031
vendor = ssh._get_ssh_vendor()
1033
vendor = self._vendor
1034
self._ssh_connection = vendor.connect_ssh(self._ssh_params.username,
1035
self._ssh_params.password, self._ssh_params.host,
1036
self._ssh_params.port,
1037
command=[self._ssh_params.bzr_remote_path, 'serve', '--inet',
1038
'--directory=/', '--allow-writes'])
1039
io_kind, io_object = self._ssh_connection.get_sock_or_pipes()
1040
if io_kind == 'socket':
1041
self._real_medium = SmartClientAlreadyConnectedSocketMedium(
1042
self.base, io_object)
1043
elif io_kind == 'pipes':
1044
read_from, write_to = io_object
1045
self._real_medium = SmartSimplePipesClientMedium(
1046
read_from, write_to, self.base)
1048
raise AssertionError(
1049
"Unexpected io_kind %r from %r"
1050
% (io_kind, self._ssh_connection))
1051
for hook in transport.Transport.hooks["post_connect"]:
1055
"""See SmartClientStreamMedium._flush()."""
1056
self._real_medium._flush()
1058
def _read_bytes(self, count):
1059
"""See SmartClientStreamMedium.read_bytes."""
1060
if self._real_medium is None:
1061
raise errors.MediumNotConnected(self)
1062
return self._real_medium.read_bytes(count)
1065
# Port 4155 is the default port for bzr://, registered with IANA.
1066
BZR_DEFAULT_INTERFACE = None
1067
BZR_DEFAULT_PORT = 4155
1070
class SmartClientSocketMedium(SmartClientStreamMedium):
1071
"""A client medium using a socket.
1073
This class isn't usable directly. Use one of its subclasses instead.
1076
def __init__(self, base):
1077
SmartClientStreamMedium.__init__(self, base)
1079
self._connected = False
1081
def _accept_bytes(self, bytes):
1082
"""See SmartClientMedium.accept_bytes."""
1083
self._ensure_connection()
1084
osutils.send_all(self._socket, bytes, self._report_activity)
1086
def _ensure_connection(self):
1087
"""Connect this medium if not already connected."""
1088
raise NotImplementedError(self._ensure_connection)
1091
"""See SmartClientStreamMedium._flush().
1093
For sockets we do no flushing. For TCP sockets we may want to turn off
1094
TCP_NODELAY and add a means to do a flush, but that can be done in the
1098
def _read_bytes(self, count):
1099
"""See SmartClientMedium.read_bytes."""
1100
if not self._connected:
1101
raise errors.MediumNotConnected(self)
1102
return osutils.read_bytes_from_socket(
1103
self._socket, self._report_activity)
1105
def disconnect(self):
1106
"""See SmartClientMedium.disconnect()."""
1107
if not self._connected:
1109
self._socket.close()
1111
self._connected = False
1114
class SmartTCPClientMedium(SmartClientSocketMedium):
1115
"""A client medium that creates a TCP connection."""
1117
def __init__(self, host, port, base):
1118
"""Creates a client that will connect on the first use."""
1119
SmartClientSocketMedium.__init__(self, base)
1123
def _ensure_connection(self):
1124
"""Connect this medium if not already connected."""
1127
if self._port is None:
1128
port = BZR_DEFAULT_PORT
1130
port = int(self._port)
1132
sockaddrs = socket.getaddrinfo(self._host, port, socket.AF_UNSPEC,
1133
socket.SOCK_STREAM, 0, 0)
1134
except socket.gaierror as xxx_todo_changeme:
1135
(err_num, err_msg) = xxx_todo_changeme.args
1136
raise errors.ConnectionError("failed to lookup %s:%d: %s" %
1137
(self._host, port, err_msg))
1138
# Initialize err in case there are no addresses returned:
1139
last_err = socket.error("no address found for %s" % self._host)
1140
for (family, socktype, proto, canonname, sockaddr) in sockaddrs:
1142
self._socket = socket.socket(family, socktype, proto)
1143
self._socket.setsockopt(socket.IPPROTO_TCP,
1144
socket.TCP_NODELAY, 1)
1145
self._socket.connect(sockaddr)
1146
except socket.error as err:
1147
if self._socket is not None:
1148
self._socket.close()
1153
if self._socket is None:
1154
# socket errors either have a (string) or (errno, string) as their
1156
if isinstance(last_err.args, str):
1157
err_msg = last_err.args
1159
err_msg = last_err.args[1]
1160
raise errors.ConnectionError("failed to connect to %s:%d: %s" %
1161
(self._host, port, err_msg))
1162
self._connected = True
1163
for hook in transport.Transport.hooks["post_connect"]:
1167
class SmartClientAlreadyConnectedSocketMedium(SmartClientSocketMedium):
1168
"""A client medium for an already connected socket.
1170
Note that this class will assume it "owns" the socket, so it will close it
1171
when its disconnect method is called.
1174
def __init__(self, base, sock):
1175
SmartClientSocketMedium.__init__(self, base)
1177
self._connected = True
1179
def _ensure_connection(self):
1180
# Already connected, by definition! So nothing to do.
1184
class SmartClientStreamMediumRequest(SmartClientMediumRequest):
1185
"""A SmartClientMediumRequest that works with an SmartClientStreamMedium."""
1187
def __init__(self, medium):
1188
SmartClientMediumRequest.__init__(self, medium)
1189
# check that we are safe concurrency wise. If some streams start
1190
# allowing concurrent requests - i.e. via multiplexing - then this
1191
# assert should be moved to SmartClientStreamMedium.get_request,
1192
# and the setting/unsetting of _current_request likewise moved into
1193
# that class : but its unneeded overhead for now. RBC 20060922
1194
if self._medium._current_request is not None:
1195
raise errors.TooManyConcurrentRequests(self._medium)
1196
self._medium._current_request = self
1198
def _accept_bytes(self, bytes):
1199
"""See SmartClientMediumRequest._accept_bytes.
1201
This forwards to self._medium._accept_bytes because we are operating
1202
on the mediums stream.
1204
self._medium._accept_bytes(bytes)
1206
def _finished_reading(self):
1207
"""See SmartClientMediumRequest._finished_reading.
1209
This clears the _current_request on self._medium to allow a new
1210
request to be created.
1212
if self._medium._current_request is not self:
1213
raise AssertionError()
1214
self._medium._current_request = None
1216
def _finished_writing(self):
1217
"""See SmartClientMediumRequest._finished_writing.
1219
This invokes self._medium._flush to ensure all bytes are transmitted.
1221
self._medium._flush()
added
removed
breezy/bzr/smart/medium.py
