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from bzrlib.lazy_import import lazy_import
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lazy_import(globals(), """
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from bzrlib import (
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from bzrlib.smart.protocol import (
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SmartClientRequestProtocolOne,
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SmartServerRequestProtocolOne,
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SmartServerRequestProtocolTwo,
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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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class SmartServerStreamMedium(object):
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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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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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self.socket = sock
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def _serve_one_request_unguarded(self, protocol):
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while protocol.next_read_size():
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protocol.accept_bytes(self.push_back)
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bytes = self._get_bytes(4096)
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protocol.accept_bytes(bytes)
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self.push_back = protocol.excess_buffer
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def _get_bytes(self, desired_count):
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# We ignore the desired_count because on sockets it's more efficient to
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return self.socket.recv(4096)
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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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"""Called when an unhandled exception from the protocol occurs."""
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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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self.socket.close()
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self.finished = True
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def _write_out(self, bytes):
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osutils.send_all(self.socket, 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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return self._read_bytes(count)
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def _read_bytes(self, count):
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"""Helper for read_bytes.
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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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raise NotImplementedError(self._read_bytes)
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return self._medium.read_bytes(count)
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def read_line(self):
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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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# XXX: this duplicates SmartClientRequestProtocolOne._recv_tuple
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while not line or line[-1] != '\n':
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new_char = self.read_bytes(1)
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# end of file encountered reading from server
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raise errors.ConnectionReset(
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"please check connectivity and permissions",
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"(and try -Dhpss if further diagnosis is required)")
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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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class SmartClientMedium(object):
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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 _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 atexit functions
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are run, the total number of calls made on that medium are reported via
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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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atexit.register(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('HPSS calls: %d (%d vfs) %s',
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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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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 the best protocol version to use."""
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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 self._protocol_version is None:
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if not self._done_hello:
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628
medium_request = self.get_request()
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# Send a 'hello' request in protocol version one, for maximum
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630
# backwards compatibility.
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client_protocol = SmartClientRequestProtocolOne(medium_request)
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self._protocol_version = client_protocol.query_version()
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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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635
# Cache the error, just like we would cache a successful
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637
self._protocol_version_error = e
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return self._protocol_version
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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
651
accesses. So for those transports, their media should return True here
652
so that RemoteBzrDirFormat can determine if it is appropriate for that
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657
def disconnect(self):
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658
"""If this medium maintains a persistent connection, close it.
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660
The default implementation does nothing.
663
def remote_path_from_transport(self, transport):
664
"""Convert transport into a path suitable for using in a request.
666
Note that the resulting remote path doesn't encode the host name or
667
anything but path, so it is only safe to use it in requests sent over
668
the medium from the matching transport.
670
medium_base = urlutils.join(self.base, '/')
671
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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738
def _read_bytes(self, count):
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739
"""See SmartClientStreamMedium._read_bytes."""
472
return self._readable_pipe.read(count)
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bytes = osutils.until_no_eintr(self._readable_pipe.read, count)
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self._report_activity(len(bytes), 'read')
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745
class SmartSSHClientMedium(SmartClientStreamMedium):
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"""A client medium using SSH."""
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def __init__(self, host, port=None, username=None, password=None,
479
vendor=None, bzr_remote_path=None):
749
base=None, vendor=None, bzr_remote_path=None):
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750
"""Creates a client that will connect on the first use.
482
752
:param vendor: An optional override for the ssh vendor to use. See
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753
bzrlib.transport.ssh for details on ssh vendors.
485
SmartClientStreamMedium.__init__(self)
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755
self._connected = False
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756
self._host = host
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self._password = password
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self._port = port
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self._username = username
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# for the benefit of progress making a short description of this
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self._scheme = 'bzr+ssh'
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# SmartClientStreamMedium stores the repr of this object in its
764
# _DebugCounter so we have to store all the values used in our repr
765
# method before calling the super init.
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SmartClientStreamMedium.__init__(self, base)
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767
self._read_from = None
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768
self._ssh_connection = None
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769
self._vendor = vendor
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770
self._write_to = None
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771
self._bzr_remote_path = bzr_remote_path
496
if self._bzr_remote_path is None:
497
symbol_versioning.warn(
498
'bzr_remote_path is required as of bzr 0.92',
499
DeprecationWarning, stacklevel=2)
500
self._bzr_remote_path = os.environ.get('BZR_REMOTE_PATH', 'bzr')
774
if self._port is None:
777
maybe_port = ':%s' % self._port
778
return "%s(%s://%s@%s%s/)" % (
779
self.__class__.__name__,
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785
def _accept_bytes(self, bytes):
503
786
"""See SmartClientStreamMedium.accept_bytes."""
504
787
self._ensure_connection()
505
788
self._write_to.write(bytes)
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self._report_activity(len(bytes), 'write')
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791
def disconnect(self):
508
792
"""See SmartClientMedium.disconnect()."""
added
removed
bzrlib/smart/medium.py
