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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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bzrlib/transport/smart/__init__.py.
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from bzrlib.lazy_import import lazy_import
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lazy_import(globals(), """
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from bzrlib.i18n import gettext
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from bzrlib.smart import client, protocol, request, vfs
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from bzrlib.transport import ssh
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from bzrlib import osutils
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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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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('\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, bytes):
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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 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 = bytes
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def _get_push_back_buffer(self):
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if self._push_back_buffer == '':
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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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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='/'):
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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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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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stderr.write("%s terminating on exception %s\n" % (self, e))
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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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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 _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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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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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 _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):
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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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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 _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('\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 errors.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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bzrlib.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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bzrlib.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)
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if medium._is_remote_before(needed_version):
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fallback_to_pre_1_2_rpc()
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except UnknownSmartMethod:
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medium._remember_remote_is_before(needed_version)
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fallback_to_pre_1_2_rpc()
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:seealso: _remember_remote_is_before
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if self._remote_version_is_before is None:
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# So far, the remote side seems to support everything
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return version_tuple >= self._remote_version_is_before
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def _remember_remote_is_before(self, version_tuple):
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"""Tell this medium that the remote side is older the given version.
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:seealso: _is_remote_before
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if (self._remote_version_is_before is not None and
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version_tuple > self._remote_version_is_before):
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# We have been told that the remote side is older than some version
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# which is newer than a previously supplied older-than version.
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# This indicates that some smart verb call is not guarded
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# appropriately (it should simply not have been tried).
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"_remember_remote_is_before(%r) called, but "
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"_remember_remote_is_before(%r) was called previously."
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, version_tuple, self._remote_version_is_before)
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if 'hpss' in debug.debug_flags:
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ui.ui_factory.show_warning(
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"_remember_remote_is_before(%r) called, but "
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"_remember_remote_is_before(%r) was called previously."
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% (version_tuple, self._remote_version_is_before))
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self._remote_version_is_before = version_tuple
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def protocol_version(self):
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"""Find out if 'hello' smart request works."""
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if self._protocol_version_error is not None:
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raise self._protocol_version_error
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if not self._done_hello:
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medium_request = self.get_request()
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# Send a 'hello' request in protocol version one, for maximum
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# backwards compatibility.
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client_protocol = protocol.SmartClientRequestProtocolOne(medium_request)
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client_protocol.query_version()
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self._done_hello = True
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except errors.SmartProtocolError, e:
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# Cache the error, just like we would cache a successful
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self._protocol_version_error = e
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def should_probe(self):
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"""Should RemoteBzrDirFormat.probe_transport send a smart request on
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Some transports are unambiguously smart-only; there's no need to check
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if the transport is able to carry smart requests, because that's all
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it is for. In those cases, this method should return False.
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But some HTTP transports can sometimes fail to carry smart requests,
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but still be usuable for accessing remote bzrdirs via plain file
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accesses. So for those transports, their media should return True here
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so that RemoteBzrDirFormat can determine if it is appropriate for that
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def disconnect(self):
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"""If this medium maintains a persistent connection, close it.
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The default implementation does nothing.
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def remote_path_from_transport(self, transport):
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"""Convert transport into a path suitable for using in a request.
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Note that the resulting remote path doesn't encode the host name or
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anything but path, so it is only safe to use it in requests sent over
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the medium from the matching transport.
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medium_base = urlutils.join(self.base, '/')
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rel_url = urlutils.relative_url(medium_base, transport.base)
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return urllib.unquote(rel_url)
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class SmartClientStreamMedium(SmartClientMedium):
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"""Stream based medium common class.
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SmartClientStreamMediums operate on a stream. All subclasses use a common
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SmartClientStreamMediumRequest for their requests, and should implement
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_accept_bytes and _read_bytes to allow the request objects to send and
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def __init__(self, base):
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SmartClientMedium.__init__(self, base)
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self._current_request = None
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def accept_bytes(self, bytes):
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self._accept_bytes(bytes)
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"""The SmartClientStreamMedium knows how to close the stream when it is
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"""Flush the output stream.
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This method is used by the SmartClientStreamMediumRequest to ensure that
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all data for a request is sent, to avoid long timeouts or deadlocks.
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raise NotImplementedError(self._flush)
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def get_request(self):
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"""See SmartClientMedium.get_request().
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SmartClientStreamMedium always returns a SmartClientStreamMediumRequest
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return SmartClientStreamMediumRequest(self)
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class SmartSimplePipesClientMedium(SmartClientStreamMedium):
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"""A client medium using simple pipes.
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This client does not manage the pipes: it assumes they will always be open.
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def __init__(self, readable_pipe, writeable_pipe, base):
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SmartClientStreamMedium.__init__(self, base)
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self._readable_pipe = readable_pipe
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self._writeable_pipe = writeable_pipe
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def _accept_bytes(self, bytes):
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"""See SmartClientStreamMedium.accept_bytes."""
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self._writeable_pipe.write(bytes)
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self._report_activity(len(bytes), 'write')
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"""See SmartClientStreamMedium._flush()."""
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self._writeable_pipe.flush()
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def _read_bytes(self, count):
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"""See SmartClientStreamMedium._read_bytes."""
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bytes_to_read = min(count, _MAX_READ_SIZE)
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bytes = self._readable_pipe.read(bytes_to_read)
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self._report_activity(len(bytes), 'read')
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class SSHParams(object):
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"""A set of parameters for starting a remote bzr via SSH."""
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def __init__(self, host, port=None, username=None, password=None,
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bzr_remote_path='bzr'):
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self.username = username
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self.password = password
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self.bzr_remote_path = bzr_remote_path
778
class SmartSSHClientMedium(SmartClientStreamMedium):
779
"""A client medium using SSH.
781
It delegates IO to a SmartClientSocketMedium or
782
SmartClientAlreadyConnectedSocketMedium (depending on platform).
785
def __init__(self, base, ssh_params, vendor=None):
786
"""Creates a client that will connect on the first use.
788
:param ssh_params: A SSHParams instance.
789
:param vendor: An optional override for the ssh vendor to use. See
790
bzrlib.transport.ssh for details on ssh vendors.
792
self._real_medium = None
793
self._ssh_params = ssh_params
794
# for the benefit of progress making a short description of this
796
self._scheme = 'bzr+ssh'
797
# SmartClientStreamMedium stores the repr of this object in its
798
# _DebugCounter so we have to store all the values used in our repr
799
# method before calling the super init.
800
SmartClientStreamMedium.__init__(self, base)
801
self._vendor = vendor
802
self._ssh_connection = None
805
if self._ssh_params.port is None:
808
maybe_port = ':%s' % self._ssh_params.port
809
return "%s(%s://%s@%s%s/)" % (
810
self.__class__.__name__,
812
self._ssh_params.username,
813
self._ssh_params.host,
816
def _accept_bytes(self, bytes):
817
"""See SmartClientStreamMedium.accept_bytes."""
818
self._ensure_connection()
819
self._real_medium.accept_bytes(bytes)
821
def disconnect(self):
822
"""See SmartClientMedium.disconnect()."""
823
if self._real_medium is not None:
824
self._real_medium.disconnect()
825
self._real_medium = None
826
if self._ssh_connection is not None:
827
self._ssh_connection.close()
828
self._ssh_connection = None
830
def _ensure_connection(self):
831
"""Connect this medium if not already connected."""
832
if self._real_medium is not None:
834
if self._vendor is None:
835
vendor = ssh._get_ssh_vendor()
837
vendor = self._vendor
838
self._ssh_connection = vendor.connect_ssh(self._ssh_params.username,
839
self._ssh_params.password, self._ssh_params.host,
840
self._ssh_params.port,
841
command=[self._ssh_params.bzr_remote_path, 'serve', '--inet',
842
'--directory=/', '--allow-writes'])
843
io_kind, io_object = self._ssh_connection.get_sock_or_pipes()
844
if io_kind == 'socket':
845
self._real_medium = SmartClientAlreadyConnectedSocketMedium(
846
self.base, io_object)
847
elif io_kind == 'pipes':
848
read_from, write_to = io_object
849
self._real_medium = SmartSimplePipesClientMedium(
850
read_from, write_to, self.base)
852
raise AssertionError(
853
"Unexpected io_kind %r from %r"
854
% (io_kind, self._ssh_connection))
857
"""See SmartClientStreamMedium._flush()."""
858
self._real_medium._flush()
860
def _read_bytes(self, count):
861
"""See SmartClientStreamMedium.read_bytes."""
862
if self._real_medium is None:
863
raise errors.MediumNotConnected(self)
864
return self._real_medium.read_bytes(count)
867
# Port 4155 is the default port for bzr://, registered with IANA.
868
BZR_DEFAULT_INTERFACE = None
869
BZR_DEFAULT_PORT = 4155
872
class SmartClientSocketMedium(SmartClientStreamMedium):
873
"""A client medium using a socket.
875
This class isn't usable directly. Use one of its subclasses instead.
878
def __init__(self, base):
879
SmartClientStreamMedium.__init__(self, base)
881
self._connected = False
883
def _accept_bytes(self, bytes):
884
"""See SmartClientMedium.accept_bytes."""
885
self._ensure_connection()
886
osutils.send_all(self._socket, bytes, self._report_activity)
888
def _ensure_connection(self):
889
"""Connect this medium if not already connected."""
890
raise NotImplementedError(self._ensure_connection)
893
"""See SmartClientStreamMedium._flush().
895
For sockets we do no flushing. For TCP sockets we may want to turn off
896
TCP_NODELAY and add a means to do a flush, but that can be done in the
900
def _read_bytes(self, count):
901
"""See SmartClientMedium.read_bytes."""
902
if not self._connected:
903
raise errors.MediumNotConnected(self)
904
return osutils.read_bytes_from_socket(
905
self._socket, self._report_activity)
907
def disconnect(self):
908
"""See SmartClientMedium.disconnect()."""
909
if not self._connected:
913
self._connected = False
916
class SmartTCPClientMedium(SmartClientSocketMedium):
917
"""A client medium that creates a TCP connection."""
919
def __init__(self, host, port, base):
920
"""Creates a client that will connect on the first use."""
921
SmartClientSocketMedium.__init__(self, base)
925
def _ensure_connection(self):
926
"""Connect this medium if not already connected."""
929
if self._port is None:
930
port = BZR_DEFAULT_PORT
932
port = int(self._port)
934
sockaddrs = socket.getaddrinfo(self._host, port, socket.AF_UNSPEC,
935
socket.SOCK_STREAM, 0, 0)
936
except socket.gaierror, (err_num, err_msg):
937
raise errors.ConnectionError("failed to lookup %s:%d: %s" %
938
(self._host, port, err_msg))
939
# Initialize err in case there are no addresses returned:
940
err = socket.error("no address found for %s" % self._host)
941
for (family, socktype, proto, canonname, sockaddr) in sockaddrs:
943
self._socket = socket.socket(family, socktype, proto)
944
self._socket.setsockopt(socket.IPPROTO_TCP,
945
socket.TCP_NODELAY, 1)
946
self._socket.connect(sockaddr)
947
except socket.error, err:
948
if self._socket is not None:
953
if self._socket is None:
954
# socket errors either have a (string) or (errno, string) as their
956
if type(err.args) is str:
959
err_msg = err.args[1]
960
raise errors.ConnectionError("failed to connect to %s:%d: %s" %
961
(self._host, port, err_msg))
962
self._connected = True
965
class SmartClientAlreadyConnectedSocketMedium(SmartClientSocketMedium):
966
"""A client medium for an already connected socket.
968
Note that this class will assume it "owns" the socket, so it will close it
969
when its disconnect method is called.
972
def __init__(self, base, sock):
973
SmartClientSocketMedium.__init__(self, base)
975
self._connected = True
977
def _ensure_connection(self):
978
# Already connected, by definition! So nothing to do.
982
class SmartClientStreamMediumRequest(SmartClientMediumRequest):
983
"""A SmartClientMediumRequest that works with an SmartClientStreamMedium."""
985
def __init__(self, medium):
986
SmartClientMediumRequest.__init__(self, medium)
987
# check that we are safe concurrency wise. If some streams start
988
# allowing concurrent requests - i.e. via multiplexing - then this
989
# assert should be moved to SmartClientStreamMedium.get_request,
990
# and the setting/unsetting of _current_request likewise moved into
991
# that class : but its unneeded overhead for now. RBC 20060922
992
if self._medium._current_request is not None:
993
raise errors.TooManyConcurrentRequests(self._medium)
994
self._medium._current_request = self
996
def _accept_bytes(self, bytes):
997
"""See SmartClientMediumRequest._accept_bytes.
999
This forwards to self._medium._accept_bytes because we are operating
1000
on the mediums stream.
1002
self._medium._accept_bytes(bytes)
1004
def _finished_reading(self):
1005
"""See SmartClientMediumRequest._finished_reading.
1007
This clears the _current_request on self._medium to allow a new
1008
request to be created.
1010
if self._medium._current_request is not self:
1011
raise AssertionError()
1012
self._medium._current_request = None
1014
def _finished_writing(self):
1015
"""See SmartClientMediumRequest._finished_writing.
1017
This invokes self._medium._flush to ensure all bytes are transmitted.
1019
self._medium._flush()
added
removed
bzrlib/smart/medium.py
