lbry-sdk/lbrynet/core/client/ClientProtocol.py
Jack 1720cce3b0 negotiated downloads
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2016-09-27 13:52:44 -04:00

258 lines
10 KiB
Python

import json
import logging
from twisted.internet import error, defer
from twisted.internet.protocol import Protocol, ClientFactory
from twisted.python import failure
from lbrynet.conf import MAX_RESPONSE_INFO_SIZE as MAX_RESPONSE_SIZE
from lbrynet.core.Error import ConnectionClosedBeforeResponseError, NoResponseError
from lbrynet.core.Error import DownloadCanceledError, MisbehavingPeerError
from lbrynet.core.Error import RequestCanceledError
from lbrynet.interfaces import IRequestSender, IRateLimited
from zope.interface import implements
log = logging.getLogger(__name__)
class ClientProtocol(Protocol):
implements(IRequestSender, IRateLimited)
######### Protocol #########
def connectionMade(self):
self._connection_manager = self.factory.connection_manager
self._rate_limiter = self.factory.rate_limiter
self.peer = self.factory.peer
self._response_deferreds = {}
self._response_buff = ''
self._downloading_blob = False
self._blob_download_request = None
self._next_request = {}
self.connection_closed = False
self.connection_closing = False
self.peer.report_up()
self._ask_for_request()
def dataReceived(self, data):
self._rate_limiter.report_dl_bytes(len(data))
if self._downloading_blob is True:
self._blob_download_request.write(data)
else:
self._response_buff += data
if len(self._response_buff) > MAX_RESPONSE_SIZE:
log.warning("Response is too large. Size %s", len(self._response_buff))
self.transport.loseConnection()
response, extra_data = self._get_valid_response(self._response_buff)
if response is not None:
self._response_buff = ''
self._handle_response(response)
if self._downloading_blob is True and len(extra_data) != 0:
self._blob_download_request.write(extra_data)
def connectionLost(self, reason):
self.connection_closed = True
if reason.check(error.ConnectionDone):
err = failure.Failure(ConnectionClosedBeforeResponseError())
else:
err = reason
#if self._response_deferreds:
# log.warning("Lost connection with active response deferreds. %s", str(self._response_deferreds))
for key, d in self._response_deferreds.items():
del self._response_deferreds[key]
d.errback(err)
if self._blob_download_request is not None:
self._blob_download_request.cancel(err)
self._connection_manager.protocol_disconnected(self.peer, self)
######### IRequestSender #########
def add_request(self, request):
if request.response_identifier in self._response_deferreds:
return defer.fail(failure.Failure(ValueError("There is already a request for that response active")))
self._next_request.update(request.request_dict)
d = defer.Deferred()
log.debug("Adding a request. Request: %s", str(request.request_dict))
self._response_deferreds[request.response_identifier] = d
return d
def add_blob_request(self, blob_request):
if self._blob_download_request is None:
d = self.add_request(blob_request)
self._blob_download_request = blob_request
blob_request.finished_deferred.addCallbacks(self._downloading_finished,
self._downloading_failed)
blob_request.finished_deferred.addErrback(self._handle_response_error)
return d
else:
return defer.fail(failure.Failure(ValueError("There is already a blob download request active")))
def cancel_requests(self):
self.connection_closing = True
ds = []
err = failure.Failure(RequestCanceledError())
for key, d in self._response_deferreds.items():
del self._response_deferreds[key]
d.errback(err)
ds.append(d)
if self._blob_download_request is not None:
self._blob_download_request.cancel(err)
ds.append(self._blob_download_request.finished_deferred)
self._blob_download_request = None
return defer.DeferredList(ds)
######### Internal request handling #########
def _handle_request_error(self, err):
log.error("An unexpected error occurred creating or sending a request to %s. Error message: %s",
str(self.peer), err.getTraceback())
self.transport.loseConnection()
def _ask_for_request(self):
log.debug("In _ask_for_request")
if self.connection_closed is True or self.connection_closing is True:
return
def send_request_or_close(do_request):
if do_request is True:
request_msg, self._next_request = self._next_request, {}
self._send_request_message(request_msg)
else:
# The connection manager has indicated that this connection should be terminated
log.info("Closing the connection to %s due to having no further requests to send", str(self.peer))
self.transport.loseConnection()
d = self._connection_manager.get_next_request(self.peer, self)
d.addCallback(send_request_or_close)
d.addErrback(self._handle_request_error)
def _send_request_message(self, request_msg):
# TODO: compare this message to the last one. If they're the same,
# TODO: incrementally delay this message.
m = json.dumps(request_msg)
self.transport.write(m)
def _get_valid_response(self, response_msg):
extra_data = None
response = None
curr_pos = 0
while 1:
next_close_paren = response_msg.find('}', curr_pos)
if next_close_paren != -1:
curr_pos = next_close_paren + 1
try:
response = json.loads(response_msg[:curr_pos])
except ValueError:
pass
else:
extra_data = response_msg[curr_pos:]
break
else:
break
return response, extra_data
def _handle_response_error(self, err):
# If an error gets to this point, log it and kill the connection.
if not err.check(MisbehavingPeerError, ConnectionClosedBeforeResponseError, DownloadCanceledError,
RequestCanceledError):
log.error("The connection to %s is closing due to an unexpected error: %s", str(self.peer),
err.getErrorMessage())
if not err.check(RequestCanceledError): # The connection manager is closing the connection, so
# there's no need to do it here.
return err
def _handle_response(self, response):
ds = []
log.debug("Handling a response. Current expected responses: %s", str(self._response_deferreds))
for key, val in response.items():
if key in self._response_deferreds:
d = self._response_deferreds[key]
del self._response_deferreds[key]
d.callback({key: val})
ds.append(d)
for k, d in self._response_deferreds.items():
del self._response_deferreds[k]
d.errback(failure.Failure(NoResponseError()))
ds.append(d)
if self._blob_download_request is not None:
self._downloading_blob = True
d = self._blob_download_request.finished_deferred
d.addErrback(self._handle_response_error)
ds.append(d)
dl = defer.DeferredList(ds, consumeErrors=True)
def get_next_request(results):
failed = False
for success, result in results:
if success is False:
failed = True
if not isinstance(result.value, DownloadCanceledError):
log.info(result.value)
log.info("The connection is closing due to an error: %s", str(result.getTraceback()))
if failed is False:
log.debug("Asking for another request.")
from twisted.internet import reactor
reactor.callLater(0, self._ask_for_request)
#self._ask_for_request()
else:
log.debug("Not asking for another request.")
self.transport.loseConnection()
dl.addCallback(get_next_request)
def _downloading_finished(self, arg):
log.debug("The blob has finished downloading")
self._blob_download_request = None
self._downloading_blob = False
return arg
def _downloading_failed(self, err):
if err.check(DownloadCanceledError):
# TODO: (wish-list) it seems silly to close the connection over this, and it shouldn't
# TODO: always be this way. it's done this way now because the client has no other way
# TODO: of telling the server it wants the download to stop. It would be great if the
# TODO: protocol had such a mechanism.
log.debug("Closing the connection to %s because the download of blob %s was canceled",
str(self.peer), str(self._blob_download_request.blob))
#self.transport.loseConnection()
#return True
return err
######### IRateLimited #########
def throttle_upload(self):
pass
def unthrottle_upload(self):
pass
def throttle_download(self):
self.transport.pauseProducing()
def unthrottle_download(self):
self.transport.resumeProducing()
class ClientProtocolFactory(ClientFactory):
protocol = ClientProtocol
def __init__(self, peer, rate_limiter, connection_manager):
self.peer = peer
self.rate_limiter = rate_limiter
self.connection_manager = connection_manager
self.p = None
def clientConnectionFailed(self, connector, reason):
self.peer.report_down()
self.connection_manager.protocol_disconnected(self.peer, connector)
def buildProtocol(self, addr):
p = self.protocol()
p.factory = self
self.p = p
return p