lbry-sdk/lbrynet/core/client/ClientProtocol.py
2018-08-24 11:42:06 -04:00

284 lines
11 KiB
Python

import json
import logging
from decimal import Decimal
from twisted.internet import error, defer
from twisted.internet.protocol import Protocol, ClientFactory
from twisted.protocols.policies import TimeoutMixin
from twisted.python import failure
from lbrynet import conf
from lbrynet.core import utils
from lbrynet.core.Error import ConnectionClosedBeforeResponseError, NoResponseError
from lbrynet.core.Error import DownloadCanceledError, MisbehavingPeerError
from lbrynet.core.Error import RequestCanceledError
log = logging.getLogger(__name__)
def encode_decimal(obj):
if isinstance(obj, Decimal):
return float(obj)
raise TypeError(repr(obj) + " is not JSON serializable")
class ClientProtocol(Protocol, TimeoutMixin):
#implements(IRequestSender, IRateLimited)
######### Protocol #########
PROTOCOL_TIMEOUT = 30
def connectionMade(self):
log.debug("Connection made to %s", self.factory.peer)
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 = b''
self._downloading_blob = False
self._blob_download_request = None
self._next_request = {}
self.connection_closed = False
self.connection_closing = False
# This needs to be set for TimeoutMixin
self.callLater = utils.call_later
self.peer.report_up()
self._ask_for_request()
def dataReceived(self, data):
log.debug("Received %d bytes from %s", len(data), self.peer)
self.setTimeout(None)
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) > conf.settings['MAX_RESPONSE_INFO_SIZE']:
log.warning("Response is too large from %s. Size %s",
self.peer, 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 = b''
self._handle_response(response)
if self._downloading_blob is True and len(extra_data) != 0:
self._blob_download_request.write(extra_data)
def timeoutConnection(self):
log.info("Connection timed out to %s", self.peer)
self.peer.report_down()
self.transport.abortConnection()
def connectionLost(self, reason=None):
log.debug("Connection lost to %s: %s", self.peer, reason)
self.setTimeout(None)
self.connection_closed = True
if reason.check(error.ConnectionDone) or reason is None:
err = failure.Failure(ConnectionClosedBeforeResponseError())
else:
err = reason
for key, d in self._response_deferreds.items():
d.errback(err)
self._response_deferreds.clear()
if self._blob_download_request is not None:
self._blob_download_request.cancel(err)
self.factory.connection_was_made_deferred.callback(True)
######### IRequestSender #########
def add_request(self, request):
if request.response_identifier in self._response_deferreds:
raise 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 for %s. Request: %s", self.peer, 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._handle_response_error)
return d
else:
return defer.fail(ValueError("There is already a blob download request active"))
def cancel_requests(self):
self.connection_closing = True
ds = []
err = RequestCanceledError()
for key, d in list(self._response_deferreds.items()):
del self._response_deferreds[key]
d.errback(err)
ds.append(d)
if self._blob_download_request is not None:
ds.append(self._blob_download_request.finished_deferred)
self._blob_download_request.cancel(err)
self._blob_download_request = None
self._downloading_blob = False
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. %s: %s",
self.peer, err.type, err)
self.transport.loseConnection()
def _ask_for_request(self):
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.debug("Closing the connection to %s due to having no further requests to send",
self.peer)
self.peer.report_success()
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):
self.setTimeout(self.PROTOCOL_TIMEOUT)
# TODO: compare this message to the last one. If they're the same,
# TODO: incrementally delay this message.
m = json.dumps(request_msg, default=encode_decimal).encode()
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(b'}', 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 err.check(DownloadCanceledError, RequestCanceledError, error.ConnectionAborted,
ConnectionClosedBeforeResponseError):
# 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.info("Closing the connection to %s because the download of blob %s was canceled",
self.peer, self._blob_download_request.blob)
result = None
elif err.check(MisbehavingPeerError):
log.warning("The connection to %s is closing due to: %s", self.peer, err)
result = err
else:
log.error("The connection to %s is closing due to an unexpected error: %s",
self.peer, err)
result = err
self._blob_download_request = None
self._downloading_blob = False
self.transport.loseConnection()
return result
def _handle_response(self, response):
ds = []
log.debug(
"Handling a response from %s. Expected responses: %s. Actual responses: %s",
self.peer, self._response_deferreds.keys(), response.keys())
for key, val in response.items():
if key in self._response_deferreds:
d = self._response_deferreds.pop(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)
# TODO: are we sure we want to consume errors here
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 to %s is closing due to an error: %s",
self.peer, result.getTraceback())
self.peer.report_down()
if failed is False:
log.debug("Asking for another request from %s", self.peer)
self._ask_for_request()
else:
log.warning("Not asking for another request from %s", self.peer)
self.transport.loseConnection()
dl.addCallback(get_next_request)
def _downloading_finished(self, arg):
log.debug("The blob has finished downloading from %s", self.peer)
self._blob_download_request = None
self._downloading_blob = False
return arg
######### 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
# This defer fires and returns True when connection was
# made and completed, or fires and returns False if
# connection failed
self.connection_was_made_deferred = defer.Deferred()
def clientConnectionFailed(self, connector, reason):
log.debug("Connection failed to %s: %s", self.peer, reason)
self.peer.report_down()
self.connection_was_made_deferred.callback(False)
def buildProtocol(self, addr):
p = self.protocol()
p.factory = self
self.p = p
return p